From 44d7f67b7764f9d272dc6b799c4b8c8f34ea7ea1 Mon Sep 17 00:00:00 2001
From: Trevor Florence <tflo@google.com>
Date: Thu, 3 Nov 2022 09:31:22 -0600
Subject: [PATCH 1/7] Rewrite `Equal` to use the equality check from
 `ReadonlyEquivalent` exclusively.

This is a breaking change as I opted to remove the types that were no longer needed. They are exported though so it's likely some people depend on them.

This took a lot of tinkering. This topic and this equality check is discussed extensively at https://github.com/Microsoft/TypeScript/issues/27024

The main three work-arounds this implementation added are:
1. Explicitly handling `any` separately
2. Supporting identity unions
3. Supporting identity intersections

The only known issue is this case:

```ts
  // @ts-expect-error This is the bug.
  expectTypeOf<{foo: number} & {bar: string}>().toEqualTypeOf<{foo: number; bar: string}>()
```

@shicks and I could not find a tweak to the `Equality` check to make this work.

Instead, I added a workaround in the shape of a new `.simplified` modifier that works similar to `.not`:

```ts
  // The workaround is the new optional .simplified modifier.
  expectTypeOf<{foo: number} & {bar: string}>().simplified.toEqualTypeOf<{foo: number; bar: string}>()
```

I'm not entirely sure what to do with documenting `.simplified` because it's something you should never use unless you need it. The simplify operation tends to lose information about the types being tested (e.g., functions become `{}` and classes lose their constructors). I'll definitely update this PR to reference the `.simplified` modifier but I wanted to get a review on this approach first. One option would be to keep around all the `DeepBrand` stuff and to have `.deepBranded` or something being the modifier instead. That would have the benefit of preserving all the exported types making this less of a breaking change.
---
 src/index.ts        |  50 +++--
 test/errors.test.ts | 210 +++++++++++----------
 test/types.test.ts  | 444 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 588 insertions(+), 116 deletions(-)

diff --git a/src/index.ts b/src/index.ts
index 2e4532ba..63aecfa0 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -84,7 +84,15 @@ type ReadonlyEquivalent<X, Y> = Extends<
 export type Extends<L, R> = IsNever<L> extends true ? IsNever<R> : [L] extends [R] ? true : false
 export type StrictExtends<L, R> = Extends<DeepBrand<L>, DeepBrand<R>>
 
-export type Equal<Left, Right> = And<[StrictExtends<Left, Right>, StrictExtends<Right, Left>]>
+type StrictEqual<L, R> =
+  (<T>() => T extends (L & T) | T ? true : false) extends
+  (<T>() => T extends (R & T) | T ? true : false) ?
+    IsNever<L> extends IsNever<R> ? true : false : false
+
+export type Equal<Left, Right, Branded = true> =
+  Branded extends true
+    ? And<[StrictExtends<Left, Right>, StrictExtends<Right, Left>]>
+    : StrictEqual<Left, Right>
 
 export type Params<Actual> = Actual extends (...args: infer P) => any ? P : never
 export type ConstructorParams<Actual> = Actual extends new (...args: infer P) => any
@@ -95,7 +103,7 @@ export type ConstructorParams<Actual> = Actual extends new (...args: infer P) =>
 
 type MismatchArgs<B extends boolean, C extends boolean> = Eq<B, C> extends true ? [] : [never]
 
-export interface ExpectTypeOf<Actual, B extends boolean> {
+export interface ExpectTypeOf<Actual, B extends boolean, Branded = false> {
   toBeAny: (...MISMATCH: MismatchArgs<IsAny<Actual>, B>) => true
   toBeUnknown: (...MISMATCH: MismatchArgs<IsUnknown<Actual>, B>) => true
   toBeNever: (...MISMATCH: MismatchArgs<IsNever<Actual>, B>) => true
@@ -109,42 +117,43 @@ export interface ExpectTypeOf<Actual, B extends boolean> {
   toBeSymbol: (...MISMATCH: MismatchArgs<Extends<Actual, symbol>, B>) => true
   toBeNull: (...MISMATCH: MismatchArgs<Extends<Actual, null>, B>) => true
   toBeUndefined: (...MISMATCH: MismatchArgs<Extends<Actual, undefined>, B>) => true
-  toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>>>, B>) => true
+  toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Branded>>, B>) => true
   toMatchTypeOf: {
     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
     <Expected>(expected: Expected, ...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
   }
   toEqualTypeOf: {
-    <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected>, B>): true
-    <Expected>(expected: Expected, ...MISMATCH: MismatchArgs<Equal<Actual, Expected>, B>): true
+    <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
+    <Expected>(expected: Expected, ...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
   }
   toBeCallableWith: B extends true ? (...args: Params<Actual>) => true : never
   toBeConstructibleWith: B extends true ? (...args: ConstructorParams<Actual>) => true : never
   toHaveProperty: <K extends string>(
     key: K,
     ...MISMATCH: MismatchArgs<Extends<K, keyof Actual>, B>
-  ) => K extends keyof Actual ? ExpectTypeOf<Actual[K], B> : true
-  extract: <V>(v?: V) => ExpectTypeOf<Extract<Actual, V>, B>
-  exclude: <V>(v?: V) => ExpectTypeOf<Exclude<Actual, V>, B>
-  parameter: <K extends keyof Params<Actual>>(number: K) => ExpectTypeOf<Params<Actual>[K], B>
-  parameters: ExpectTypeOf<Params<Actual>, B>
-  constructorParameters: ExpectTypeOf<ConstructorParams<Actual>, B>
-  thisParameter: ExpectTypeOf<ThisParameterType<Actual>, B>
-  instance: Actual extends new (...args: any[]) => infer I ? ExpectTypeOf<I, B> : never
-  returns: Actual extends (...args: any[]) => infer R ? ExpectTypeOf<R, B> : never
-  resolves: Actual extends PromiseLike<infer R> ? ExpectTypeOf<R, B> : never
-  items: Actual extends ArrayLike<infer R> ? ExpectTypeOf<R, B> : never
-  guards: Actual extends (v: any, ...args: any[]) => v is infer T ? ExpectTypeOf<T, B> : never
+  ) => K extends keyof Actual ? ExpectTypeOf<Actual[K], B, Branded> : true
+  extract: <V>(v?: V) => ExpectTypeOf<Extract<Actual, V>, B, Branded>
+  exclude: <V>(v?: V) => ExpectTypeOf<Exclude<Actual, V>, B, Branded>
+  parameter: <K extends keyof Params<Actual>>(number: K) => ExpectTypeOf<Params<Actual>[K], B, Branded>
+  parameters: ExpectTypeOf<Params<Actual>, B, Branded>
+  constructorParameters: ExpectTypeOf<ConstructorParams<Actual>, B, Branded>
+  thisParameter: ExpectTypeOf<ThisParameterType<Actual>, B, Branded>
+  instance: Actual extends new (...args: any[]) => infer I ? ExpectTypeOf<I, B, Branded> : never
+  returns: Actual extends (...args: any[]) => infer R ? ExpectTypeOf<R, B, Branded> : never
+  resolves: Actual extends PromiseLike<infer R> ? ExpectTypeOf<R, B, Branded> : never
+  items: Actual extends ArrayLike<infer R> ? ExpectTypeOf<R, B, Branded> : never
+  guards: Actual extends (v: any, ...args: any[]) => v is infer T ? ExpectTypeOf<T, B, Branded> : never
   asserts: Actual extends (v: any, ...args: any[]) => asserts v is infer T
     ? // Guard methods `(v: any) => asserts v is T` does not actually defines a return type. Thus, any function taking 1 argument matches the signature before.
       // In case the inferred assertion type `R` could not be determined (so, `unknown`), consider the function as a non-guard, and return a `never` type.
       // See https://github.com/microsoft/TypeScript/issues/34636
       unknown extends T
       ? never
-      : ExpectTypeOf<T, B>
+      : ExpectTypeOf<T, B, Branded>
     : never
-  not: ExpectTypeOf<Actual, Not<B>>
-}
+    branded: Omit<ExpectTypeOf<Actual, B, true>, 'branded'>
+    not: Omit<ExpectTypeOf<Actual, Not<B>, Branded>, 'branded'>
+  }
 const fn: any = () => true
 
 export type _ExpectTypeOf = {
@@ -186,6 +195,7 @@ export const expectTypeOf: _ExpectTypeOf = <Actual>(_actual?: Actual): ExpectTyp
     'instance',
     'guards',
     'asserts',
+    'branded',
   ] as const
   type Keys = keyof ExpectTypeOf<any, any>
 
diff --git a/test/errors.test.ts b/test/errors.test.ts
index d2cc07eb..2d3910bc 100644
--- a/test/errors.test.ts
+++ b/test/errors.test.ts
@@ -18,9 +18,9 @@ test('toEqualTypeOf<...>() error message', async () => {
     3 expectTypeOf({a: 1}).toEqualTypeOf<{a: string}>()
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:118:16
-        118     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:126:16
+        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     "
   `)
@@ -43,8 +43,8 @@ test('toMatchTypeOf<...>() error message', async () => {
     3 expectTypeOf({a: 1}).toMatchTypeOf<{a: string}>()
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:114:16
-        114     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
+      src/index.ts:122:16
+        122     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     "
@@ -58,8 +58,8 @@ test('toMatchTypeOf(...) error message', async () => {
     3 expectTypeOf({a: 1}).toMatchTypeOf({a: 'one'})
                            ~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:115:36
-        115     <Expected>(expected: Expected, ...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
+      src/index.ts:123:36
+        123     <Expected>(expected: Expected, ...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
                                                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     "
@@ -86,17 +86,17 @@ test('usage test', () => {
     21   expectTypeOf({a: 1, b: 1}).toEqualTypeOf<{a: number}>()
                                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:118:16
-        118     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:126:16
+        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:35:25 - error TS2554: Expected 1 arguments, but got 0.
 
     35   expectTypeOf<Fruit>().toMatchTypeOf<Apple>()
                                ~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:114:16
-        114     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
+      src/index.ts:122:16
+        122     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:38:25 - error TS2554: Expected 1 arguments, but got 0.
@@ -104,17 +104,17 @@ test('usage test', () => {
     38   expectTypeOf<Apple>().toEqualTypeOf<Fruit>()
                                ~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:118:16
-        118     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:126:16
+        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:42:24 - error TS2554: Expected 2 arguments, but got 1.
 
     42   expectTypeOf({a: 1}).toMatchTypeOf({b: 1})
                               ~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:115:36
-        115     <Expected>(expected: Expected, ...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
+      src/index.ts:123:36
+        123     <Expected>(expected: Expected, ...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
                                                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:51:25 - error TS2554: Expected 1 arguments, but got 0.
@@ -122,8 +122,8 @@ test('usage test', () => {
     51   expectTypeOf<Fruit>().toMatchTypeOf<Apple>()
                                ~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:114:16
-        114     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
+      src/index.ts:122:16
+        122     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:52:25 - error TS2554: Expected 1 arguments, but got 0.
@@ -131,17 +131,17 @@ test('usage test', () => {
     52   expectTypeOf<Apple>().toEqualTypeOf<Fruit>()
                                ~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:118:16
-        118     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:126:16
+        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:61:25 - error TS2554: Expected 1 arguments, but got 0.
 
     61   expectTypeOf<never>().toBeNumber()
                                ~~~~~~~~~~~~
 
-      src/index.ts:105:16
-        105   toBeNumber: (...MISMATCH: MismatchArgs<Extends<Actual, number>, B>) => true
+      src/index.ts:113:16
+        113   toBeNumber: (...MISMATCH: MismatchArgs<Extends<Actual, number>, B>) => true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:65:43 - error TS2554: Expected 1 arguments, but got 0.
@@ -149,62 +149,62 @@ test('usage test', () => {
     65   expectTypeOf<{deeply: {nested: any}}>().toEqualTypeOf<{deeply: {nested: unknown}}>()
                                                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:118:16
-        118     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:126:16
+        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:83:27 - error TS2554: Expected 1 arguments, but got 0.
 
     83   expectTypeOf(undefined).toBeNullable()
                                  ~~~~~~~~~~~~~~
 
-      src/index.ts:112:18
-        112   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>>>, B>) => true
-                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:120:18
+        120   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Branded>>, B>) => true
+                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:87:22 - error TS2554: Expected 1 arguments, but got 0.
 
     87   expectTypeOf(null).toBeNullable()
                             ~~~~~~~~~~~~~~
 
-      src/index.ts:112:18
-        112   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>>>, B>) => true
-                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:120:18
+        120   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Branded>>, B>) => true
+                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:90:33 - error TS2554: Expected 1 arguments, but got 0.
 
     90   expectTypeOf<1 | undefined>().toBeNullable()
                                        ~~~~~~~~~~~~~~
 
-      src/index.ts:112:18
-        112   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>>>, B>) => true
-                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:120:18
+        120   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Branded>>, B>) => true
+                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:91:28 - error TS2554: Expected 1 arguments, but got 0.
 
     91   expectTypeOf<1 | null>().toBeNullable()
                                   ~~~~~~~~~~~~~~
 
-      src/index.ts:112:18
-        112   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>>>, B>) => true
-                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:120:18
+        120   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Branded>>, B>) => true
+                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:92:40 - error TS2554: Expected 1 arguments, but got 0.
 
     92   expectTypeOf<1 | undefined | null>().toBeNullable()
                                               ~~~~~~~~~~~~~~
 
-      src/index.ts:112:18
-        112   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>>>, B>) => true
-                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:120:18
+        120   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Branded>>, B>) => true
+                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:96:19 - error TS2554: Expected 1 arguments, but got 0.
 
     96   expectTypeOf(1).toBeUnknown()
                          ~~~~~~~~~~~~~
 
-      src/index.ts:100:17
-        100   toBeUnknown: (...MISMATCH: MismatchArgs<IsUnknown<Actual>, B>) => true
+      src/index.ts:108:17
+        108   toBeUnknown: (...MISMATCH: MismatchArgs<IsUnknown<Actual>, B>) => true
                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:97:19 - error TS2554: Expected 1 arguments, but got 0.
@@ -212,17 +212,17 @@ test('usage test', () => {
     97   expectTypeOf(1).toBeAny()
                          ~~~~~~~~~
 
-      src/index.ts:99:13
-        99   toBeAny: (...MISMATCH: MismatchArgs<IsAny<Actual>, B>) => true
-                       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:107:13
+        107   toBeAny: (...MISMATCH: MismatchArgs<IsAny<Actual>, B>) => true
+                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:98:19 - error TS2554: Expected 1 arguments, but got 0.
 
     98   expectTypeOf(1).toBeNever()
                          ~~~~~~~~~~~
 
-      src/index.ts:101:15
-        101   toBeNever: (...MISMATCH: MismatchArgs<IsNever<Actual>, B>) => true
+      src/index.ts:109:15
+        109   toBeNever: (...MISMATCH: MismatchArgs<IsNever<Actual>, B>) => true
                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:99:19 - error TS2554: Expected 1 arguments, but got 0.
@@ -230,8 +230,8 @@ test('usage test', () => {
     99   expectTypeOf(1).toBeNull()
                          ~~~~~~~~~~
 
-      src/index.ts:110:14
-        110   toBeNull: (...MISMATCH: MismatchArgs<Extends<Actual, null>, B>) => true
+      src/index.ts:118:14
+        118   toBeNull: (...MISMATCH: MismatchArgs<Extends<Actual, null>, B>) => true
                          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:100:19 - error TS2554: Expected 1 arguments, but got 0.
@@ -239,8 +239,8 @@ test('usage test', () => {
     100   expectTypeOf(1).toBeUndefined()
                           ~~~~~~~~~~~~~~~
 
-      src/index.ts:111:19
-        111   toBeUndefined: (...MISMATCH: MismatchArgs<Extends<Actual, undefined>, B>) => true
+      src/index.ts:119:19
+        119   toBeUndefined: (...MISMATCH: MismatchArgs<Extends<Actual, undefined>, B>) => true
                               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:101:19 - error TS2554: Expected 1 arguments, but got 0.
@@ -248,17 +248,17 @@ test('usage test', () => {
     101   expectTypeOf(1).toBeNullable()
                           ~~~~~~~~~~~~~~
 
-      src/index.ts:112:18
-        112   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>>>, B>) => true
-                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:120:18
+        120   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Branded>>, B>) => true
+                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:106:35 - error TS2554: Expected 1 arguments, but got 0.
 
     106   expectTypeOf<string | number>().toMatchTypeOf<number>()
                                           ~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:114:16
-        114     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
+      src/index.ts:122:16
+        122     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:130:71 - error TS2554: Expected 2 arguments, but got 1.
@@ -266,8 +266,8 @@ test('usage test', () => {
     130   expectTypeOf<ResponsiveProp<number>>().exclude<number | number[]>().toHaveProperty('xxl')
                                                                               ~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:125:5
-        125     ...MISMATCH: MismatchArgs<Extends<K, keyof Actual>, B>
+      src/index.ts:133:5
+        133     ...MISMATCH: MismatchArgs<Extends<K, keyof Actual>, B>
                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:147:21 - error TS2554: Expected 2 arguments, but got 1.
@@ -275,8 +275,8 @@ test('usage test', () => {
     147   expectTypeOf(obj).toHaveProperty('c')
                             ~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:125:5
-        125     ...MISMATCH: MismatchArgs<Extends<K, keyof Actual>, B>
+      src/index.ts:133:5
+        133     ...MISMATCH: MismatchArgs<Extends<K, keyof Actual>, B>
                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:152:41 - error TS2554: Expected 1 arguments, but got 0.
@@ -284,8 +284,8 @@ test('usage test', () => {
     152   expectTypeOf(obj).toHaveProperty('a').toBeString()
                                                 ~~~~~~~~~~~~
 
-      src/index.ts:106:16
-        106   toBeString: (...MISMATCH: MismatchArgs<Extends<Actual, string>, B>) => true
+      src/index.ts:114:16
+        114   toBeString: (...MISMATCH: MismatchArgs<Extends<Actual, string>, B>) => true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:159:27 - error TS2554: Expected 1 arguments, but got 0.
@@ -293,27 +293,27 @@ test('usage test', () => {
     159   expectTypeOf<NoParam>().toEqualTypeOf<HasParam>()
                                   ~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:118:16
-        118     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:126:16
+        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:179:19 - error TS2554: Expected 1 arguments, but got 0.
 
     179   expectTypeOf(f).toBeAny()
                           ~~~~~~~~~
 
-      src/index.ts:99:13
-        99   toBeAny: (...MISMATCH: MismatchArgs<IsAny<Actual>, B>) => true
-                       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:107:13
+        107   toBeAny: (...MISMATCH: MismatchArgs<IsAny<Actual>, B>) => true
+                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:180:27 - error TS2554: Expected 1 arguments, but got 0.
 
     180   expectTypeOf(f).returns.toBeAny()
                                   ~~~~~~~~~
 
-      src/index.ts:99:13
-        99   toBeAny: (...MISMATCH: MismatchArgs<IsAny<Actual>, B>) => true
-                       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:107:13
+        107   toBeAny: (...MISMATCH: MismatchArgs<IsAny<Actual>, B>) => true
+                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:183:46 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'never'.
 
@@ -328,8 +328,8 @@ test('usage test', () => {
     246   expectTypeOf([1, 2, 3]).items.toBeString()
                                         ~~~~~~~~~~~~
 
-      src/index.ts:106:16
-        106   toBeString: (...MISMATCH: MismatchArgs<Extends<Actual, string>, B>) => true
+      src/index.ts:114:16
+        114   toBeString: (...MISMATCH: MismatchArgs<Extends<Actual, string>, B>) => true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:258:31 - error TS2554: Expected 1 arguments, but got 0.
@@ -337,63 +337,81 @@ test('usage test', () => {
     258   expectTypeOf<{a: string}>().toEqualTypeOf<{a: number}>()
                                       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:118:16
-        118     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:126:16
+        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+        Arguments for the rest parameter 'MISMATCH' were not provided.
+    test/usage.test.ts:262:32 - error TS2554: Expected 1 arguments, but got 0.
+
+    262   expectTypeOf<{a?: number}>().toEqualTypeOf<{}>()
+                                       ~~~~~~~~~~~~~~~~~~~
+
+      src/index.ts:126:16
+        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:263:32 - error TS2554: Expected 1 arguments, but got 0.
 
     263   expectTypeOf<{a?: number}>().toEqualTypeOf<{a: number}>()
                                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:118:16
-        118     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:126:16
+        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:264:32 - error TS2554: Expected 1 arguments, but got 0.
 
     264   expectTypeOf<{a?: number}>().toEqualTypeOf<{a: number | undefined}>()
                                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:118:16
-        118     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:126:16
+        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:265:39 - error TS2554: Expected 1 arguments, but got 0.
 
     265   expectTypeOf<{a?: number | null}>().toEqualTypeOf<{a: number | null}>()
                                               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:118:16
-        118     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:126:16
+        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+        Arguments for the rest parameter 'MISMATCH' were not provided.
+    test/usage.test.ts:266:37 - error TS2554: Expected 1 arguments, but got 0.
+
+    266   expectTypeOf<{a: {b?: number}}>().toEqualTypeOf<{a: {}}>()
+                                            ~~~~~~~~~~~~~~~~~~~~~~~~
+
+      src/index.ts:126:16
+        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:274:22 - error TS2554: Expected 1 arguments, but got 0.
 
     274   expectTypeOf<A1>().toEqualTypeOf<E1>()
                              ~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:118:16
-        118     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:126:16
+        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:280:22 - error TS2554: Expected 1 arguments, but got 0.
 
     280   expectTypeOf<A2>().toEqualTypeOf<E2>()
                              ~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:118:16
-        118     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:126:16
+        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:297:28 - error TS2554: Expected 1 arguments, but got 0.
 
     297   expectTypeOf<typeof A>().toEqualTypeOf<typeof B>()
                                    ~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:118:16
-        118     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:126:16
+        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     "
   `)
diff --git a/test/types.test.ts b/test/types.test.ts
index 9e69af1c..cba2e7a7 100644
--- a/test/types.test.ts
+++ b/test/types.test.ts
@@ -189,3 +189,447 @@ test(`undefined isn't removed from unions`, () => {
   expectTypeOf<string | null | undefined>().toEqualTypeOf<string | null | undefined>()
   expectTypeOf<string | null | undefined>().toMatchTypeOf<string | null | undefined>()
 })
+
+test('Distinguish between functions whose return types differ by readonly prop', () => {
+  type ObjWithReadonlyProp = {readonly x: number}
+  type ObjWithoutReadonlyProp = {x: number}
+
+  function original(o: ObjWithReadonlyProp): ObjWithReadonlyProp {
+    return o
+  }
+
+  function same(o: ObjWithReadonlyProp): ObjWithReadonlyProp {
+    return o
+  }
+
+  function different(o: ObjWithoutReadonlyProp): ObjWithoutReadonlyProp {
+    return o
+  }
+
+  // Self-identity
+  expectTypeOf<typeof original>().toEqualTypeOf<typeof original>()
+  expectTypeOf(original).branded.toEqualTypeOf(original)
+  expectTypeOf<typeof different>().toEqualTypeOf<typeof different>()
+  expectTypeOf(different).toEqualTypeOf(different)
+  // @ts-expect-error
+  expectTypeOf<typeof original>().not.toEqualTypeOf<typeof original>()
+  // @ts-expect-error
+  expectTypeOf(original).not.toEqualTypeOf(original)
+  // @ts-expect-error
+  expectTypeOf<typeof different>().not.toEqualTypeOf<typeof different>()
+  // @ts-expect-error
+  expectTypeOf(different).not.toEqualTypeOf(different)
+
+  // Same shape
+  expectTypeOf<typeof original>().toEqualTypeOf<typeof same>()
+  expectTypeOf(original).toEqualTypeOf(same)
+  // @ts-expect-error
+  expectTypeOf<typeof original>().not.toEqualTypeOf<typeof same>()
+  // @ts-expect-error
+  expectTypeOf(original).not.toEqualTypeOf(same)
+
+  // Different presence of readonly prop
+  expectTypeOf<typeof original>().not.toEqualTypeOf<typeof different>()
+  expectTypeOf(original).not.toEqualTypeOf(different)
+  // @ts-expect-error
+  expectTypeOf<typeof original>().toEqualTypeOf<typeof different>()
+  // @ts-expect-error
+  expectTypeOf(original).toEqualTypeOf(different)
+})
+
+test('Distinguish between classes with only private properties', () => {
+  class Original {
+    // eslint-disable-next-line mmkal/@typescript-eslint/class-literal-property-style
+    private readonly prop = 1
+  }
+
+  class Different {
+    // eslint-disable-next-line mmkal/@typescript-eslint/class-literal-property-style
+    private readonly prop = 1
+  }
+
+  // Self-identity
+  expectTypeOf<Original>().toEqualTypeOf<Original>()
+  expectTypeOf(Original).toEqualTypeOf(Original)
+  expectTypeOf<Different>().toEqualTypeOf<Different>()
+  expectTypeOf(Different).toEqualTypeOf(Different)
+  // @ts-expect-error
+  expectTypeOf<Original>().not.toEqualTypeOf<Original>()
+  // @ts-expect-error
+  expectTypeOf(Original).not.toEqualTypeOf(Original)
+  // @ts-expect-error
+  expectTypeOf<Different>().not.toEqualTypeOf<Different>()
+  // @ts-expect-error
+  expectTypeOf(Different).not.toEqualTypeOf(Different)
+
+  // Different classes
+  expectTypeOf<Original>().not.toEqualTypeOf<Different>()
+  expectTypeOf(Original).not.toEqualTypeOf(Different)
+  // @ts-expect-error
+  expectTypeOf<Original>().toEqualTypeOf<Different>()
+  // @ts-expect-error
+  expectTypeOf(Original).toEqualTypeOf(Different)
+})
+
+test('Distinguish between types with generics used in type assertion', () => {
+  interface Guard<T> {
+    // eslint-disable-next-line mmkal/@typescript-eslint/prefer-function-type
+    (arg: unknown): arg is T
+  }
+
+  // Self-identity
+  expectTypeOf<Guard<number>>().toEqualTypeOf<Guard<number>>()
+  // @ts-expect-error
+  expectTypeOf<Guard<number>>().not.toEqualTypeOf<Guard<number>>()
+
+  // Different return types
+  expectTypeOf<Guard<number>>().not.toEqualTypeOf<Guard<string>>()
+  // @ts-expect-error
+  expectTypeOf<Guard<number>>().toEqualTypeOf<Guard<string>>()
+})
+
+test('Distinguish between functions with generics vs unknown', () => {
+  function funcWithGenerics<T>(p1: T, p2: T): T {
+    return p1 || p2
+  }
+
+  function funcWithUnknown(p1: unknown, p2: unknown): unknown {
+    return p1 || p2
+  }
+
+  // Self-identity
+  expectTypeOf<typeof funcWithGenerics>().toEqualTypeOf<typeof funcWithGenerics>()
+  expectTypeOf(funcWithGenerics).toEqualTypeOf(funcWithGenerics)
+  expectTypeOf<typeof funcWithUnknown>().toEqualTypeOf<typeof funcWithUnknown>()
+  expectTypeOf(funcWithUnknown).toEqualTypeOf(funcWithUnknown)
+  // @ts-expect-error
+  expectTypeOf<typeof funcWithGenerics>().not.toEqualTypeOf<typeof funcWithGenerics>()
+  // @ts-expect-error
+  expectTypeOf(funcWithGenerics).not.toEqualTypeOf(funcWithGenerics)
+  // @ts-expect-error
+  expectTypeOf<typeof funcWithUnknown>().not.toEqualTypeOf<typeof funcWithUnknown>()
+  // @ts-expect-error
+  expectTypeOf(funcWithUnknown).not.toEqualTypeOf(funcWithUnknown)
+
+  // Generic vs unknown with otherwise same shape
+  expectTypeOf<typeof funcWithGenerics>().not.toEqualTypeOf<typeof funcWithUnknown>()
+  expectTypeOf(funcWithGenerics).not.toEqualTypeOf(funcWithUnknown)
+  // @ts-expect-error
+  expectTypeOf<typeof funcWithGenerics>().toEqualTypeOf<typeof funcWithUnknown>()
+  // @ts-expect-error
+  expectTypeOf(funcWithGenerics).toEqualTypeOf(funcWithUnknown)
+})
+
+interface BaseFunc {
+  // eslint-disable-next-line mmkal/@typescript-eslint/prefer-function-type
+  (str: string): number
+}
+
+test('Distinguish between functions with readonly properties', () => {
+  interface Original extends BaseFunc {
+    readonly prop: string
+  }
+
+  interface Same extends BaseFunc {
+    readonly prop: string
+  }
+
+  interface Different extends BaseFunc {
+    prop: string
+  }
+
+  // Self-identity
+  expectTypeOf<Original>().toEqualTypeOf<Original>()
+  expectTypeOf<Different>().toEqualTypeOf<Different>()
+  // @ts-expect-error
+  expectTypeOf<Original>().not.toEqualTypeOf<Original>()
+  // @ts-expect-error
+  expectTypeOf<Different>().not.toEqualTypeOf<Different>()
+
+  // Same shape
+  expectTypeOf<Original>().toEqualTypeOf<Same>()
+  // @ts-expect-error
+  expectTypeOf<Original>().not.toEqualTypeOf<Same>()
+
+  // Only one readonly otherwise same shape
+  expectTypeOf<Original>().not.toEqualTypeOf<Different>()
+  // @ts-expect-error
+  expectTypeOf<Original>().toEqualTypeOf<Different>()
+})
+
+test('Distinguish between functions with optional properties', () => {
+  interface Original extends BaseFunc {
+    prop?: number
+  }
+
+  interface Same extends BaseFunc {
+    prop?: number
+  }
+
+  interface Different extends BaseFunc {
+    prop: number | undefined
+  }
+
+  // Self-identity
+  expectTypeOf<Original>().toEqualTypeOf<Original>()
+  expectTypeOf<Different>().toEqualTypeOf<Different>()
+  // @ts-expect-error
+  expectTypeOf<Original>().not.toEqualTypeOf<Original>()
+  // @ts-expect-error
+  expectTypeOf<Different>().not.toEqualTypeOf<Different>()
+
+  // Same shape
+  expectTypeOf<Original>().toEqualTypeOf<Same>()
+  // @ts-expect-error
+  expectTypeOf<Original>().not.toEqualTypeOf<Same>()
+
+  // Only one optional otherwise same shape
+  expectTypeOf<Original>().not.toEqualTypeOf<Different>()
+  // @ts-expect-error
+  expectTypeOf<Original>().toEqualTypeOf<Different>()
+})
+
+test('Distinguish between functions with properties of different types', () => {
+  interface Original extends BaseFunc {
+    prop: number
+  }
+
+  interface Same extends BaseFunc {
+    prop: number
+  }
+
+  interface Different extends BaseFunc {
+    prop: string
+  }
+
+  // Self-identity
+  expectTypeOf<Original>().toEqualTypeOf<Original>()
+  expectTypeOf<Different>().toEqualTypeOf<Different>()
+  // @ts-expect-error
+  expectTypeOf<Original>().not.toEqualTypeOf<Original>()
+  // @ts-expect-error
+  expectTypeOf<Different>().not.toEqualTypeOf<Different>()
+
+  // Same shape
+  expectTypeOf<Original>().toEqualTypeOf<Same>()
+  // @ts-expect-error
+  expectTypeOf<Original>().not.toEqualTypeOf<Same>()
+
+  // Only one optional otherwise same shape
+  expectTypeOf<Original>().not.toEqualTypeOf<Different>()
+  // @ts-expect-error
+  expectTypeOf<Original>().toEqualTypeOf<Different>()
+})
+
+interface BaseConstructor {
+  // eslint-disable-next-line mmkal/@typescript-eslint/prefer-function-type
+  new (str: string): {someProp: number}
+}
+
+test('Distinguish between constructors with readonly properties', () => {
+  interface Original extends BaseConstructor {
+    readonly prop: string
+  }
+
+  interface Same extends BaseConstructor {
+    readonly prop: string
+  }
+
+  interface Different extends BaseConstructor {
+    prop: string
+  }
+
+  // Self-identity
+  expectTypeOf<Original>().toEqualTypeOf<Original>()
+  expectTypeOf<Different>().toEqualTypeOf<Different>()
+  // @ts-expect-error
+  expectTypeOf<Original>().not.toEqualTypeOf<Original>()
+  // @ts-expect-error
+  expectTypeOf<Different>().not.toEqualTypeOf<Different>()
+
+  // Same shape
+  expectTypeOf<Original>().toEqualTypeOf<Same>()
+  // @ts-expect-error
+  expectTypeOf<Original>().not.toEqualTypeOf<Same>()
+
+  // Only one readonly otherwise same shape
+  expectTypeOf<Original>().not.toEqualTypeOf<Different>()
+  // @ts-expect-error
+  expectTypeOf<Original>().toEqualTypeOf<Different>()
+})
+
+test('Distinguish between constructors with optional properties', () => {
+  interface Original extends BaseConstructor {
+    prop?: number
+  }
+
+  interface Same extends BaseConstructor {
+    prop?: number
+  }
+
+  interface Different extends BaseConstructor {
+    prop: number | undefined
+  }
+
+  // Self-identity
+  expectTypeOf<Original>().toEqualTypeOf<Original>()
+  expectTypeOf<Different>().toEqualTypeOf<Different>()
+  // @ts-expect-error
+  expectTypeOf<Original>().not.toEqualTypeOf<Original>()
+  // @ts-expect-error
+  expectTypeOf<Different>().not.toEqualTypeOf<Different>()
+
+  // Same shape
+  expectTypeOf<Original>().toEqualTypeOf<Same>()
+  // @ts-expect-error
+  expectTypeOf<Original>().not.toEqualTypeOf<Same>()
+
+  // Only one optional otherwise same shape
+  expectTypeOf<Original>().not.toEqualTypeOf<Different>()
+  // @ts-expect-error
+  expectTypeOf<Original>().toEqualTypeOf<Different>()
+})
+
+test('Distinguish between constructors with properties of different types', () => {
+  interface Original extends BaseConstructor {
+    prop: number
+  }
+
+  interface Same extends BaseConstructor {
+    prop: number
+  }
+
+  interface Different extends BaseConstructor {
+    prop: string
+  }
+
+  // Self-identity
+  expectTypeOf<Original>().toEqualTypeOf<Original>()
+  expectTypeOf<Different>().toEqualTypeOf<Different>()
+  // @ts-expect-error
+  expectTypeOf<Original>().not.toEqualTypeOf<Original>()
+  // @ts-expect-error
+  expectTypeOf<Different>().not.toEqualTypeOf<Different>()
+
+  // Same shape
+  expectTypeOf<Original>().toEqualTypeOf<Same>()
+  // @ts-expect-error
+  expectTypeOf<Original>().not.toEqualTypeOf<Same>()
+
+  // Only one optional otherwise same shape
+  expectTypeOf<Original>().not.toEqualTypeOf<Different>()
+  // @ts-expect-error
+  expectTypeOf<Original>().toEqualTypeOf<Different>()
+})
+
+test('Distinguish between tuples with differing item type', () => {
+  type Original = [{prop: number}]
+  type Same = [{prop: number}]
+  type Different = [{readonly prop: number}]
+
+  // Self-identity
+  expectTypeOf<Original>().toEqualTypeOf<Original>()
+  expectTypeOf<Different>().toEqualTypeOf<Different>()
+  // @ts-expect-error
+  expectTypeOf<Original>().not.toEqualTypeOf<Original>()
+  // @ts-expect-error
+  expectTypeOf<Different>().not.toEqualTypeOf<Different>()
+
+  // Same shape
+  expectTypeOf<Original>().toEqualTypeOf<Same>()
+  // @ts-expect-error
+  expectTypeOf<Original>().not.toEqualTypeOf<Same>()
+
+  // One item type property readonly otherwise same sape
+  expectTypeOf<Original>().not.toEqualTypeOf<Different>()
+  // @ts-expect-error
+  expectTypeOf<Original>().toEqualTypeOf<Different>()
+})
+
+test('Distinguish between array with properties', () => {
+  type Original = number[] & {readonly prop: number}
+  type Same = number[] & {readonly prop: number}
+  type Different = number[] & {prop: number}
+
+  // Self-identity
+  expectTypeOf<Original>().toEqualTypeOf<Original>()
+  expectTypeOf<Different>().toEqualTypeOf<Different>()
+  // @ts-expect-error
+  expectTypeOf<Original>().not.toEqualTypeOf<Original>()
+  // @ts-expect-error
+  expectTypeOf<Different>().not.toEqualTypeOf<Different>()
+
+  // Same shape
+  expectTypeOf<Original>().toEqualTypeOf<Same>()
+  // @ts-expect-error
+  expectTypeOf<Original>().not.toEqualTypeOf<Same>()
+
+  // One item type property readonly otherwise same sape
+  expectTypeOf<Original>().not.toEqualTypeOf<Different>()
+  // @ts-expect-error
+  expectTypeOf<Original>().toEqualTypeOf<Different>()
+})
+
+test('Distinguish between different types that are OR`d together', () => {
+  expectTypeOf<{foo: number} | {bar: string}>().toEqualTypeOf<{foo: number} | {bar: string}>()
+  // @ts-expect-error
+  expectTypeOf<{foo: number} | {bar: string}>().not.toEqualTypeOf<{foo: number} | {bar: string}>()
+
+  expectTypeOf<{foo: number} | {bar: string}>().not.toEqualTypeOf<{foo: number}>()
+  // @ts-expect-error
+  expectTypeOf<{foo: number} | {bar: string}>().toEqualTypeOf<{foo: number}>()
+})
+
+test('Distinguish between identical types that are OR`d together', () => {
+  expectTypeOf<{foo: number} | {foo: number}>().toEqualTypeOf<{foo: number} | {foo: number}>()
+  // Note: The `| T` in `Equal` in index.ts makes this work.
+  expectTypeOf<{foo: number} | {foo: number}>().toEqualTypeOf<{foo: number}>()
+  // @ts-expect-error
+  expectTypeOf<{foo: number} | {foo: number}>().not.toEqualTypeOf<{foo: number} | {foo: number}>()
+  // @ts-expect-error
+  expectTypeOf<{foo: number} | {foo: number}>().not.toEqualTypeOf<{foo: number}>()
+})
+
+test('Distinguish between different types that are AND`d together', () => {
+  // Identity
+  expectTypeOf<{foo: number} & {bar: string}>().toEqualTypeOf<{foo: number} & {bar: string}>()
+  // @ts-expect-error
+  expectTypeOf<{foo: number} & {bar: string}>().not.toEqualTypeOf<{foo: number} & {bar: string}>()
+
+  // Two types intersect to an equivalent non-intersected type
+  // This is broken at the moment. See the next test
+  // expectTypeOf<{foo: number} & {bar: string}>().toEqualTypeOf<{foo: number; bar: string}>()
+  // expectTypeOf<{foo: number} & {bar: string}>().not.toEqualTypeOf<{foo: number; bar: string}>()
+})
+
+test('Works arounds tsc bug not handling intersected types for this form of equivalence', () => {
+  // @ts-expect-error This is the bug.
+  expectTypeOf<{foo: number} & {bar: string}>().toEqualTypeOf<{foo: number; bar: string}>()
+  // This should \@ts-expect-error but does not.
+  expectTypeOf<{foo: number} & {bar: string}>().not.toEqualTypeOf<{foo: number; bar: string}>()
+
+  const one: {foo: number} & {bar: string} = {foo: 1, bar: 'a'}
+  const two: {foo: number; bar: string} = {foo: 1, bar: 'a'}
+  // @ts-expect-error It also repros with variables and their inferred types
+  expectTypeOf(one).toEqualTypeOf(two)
+  // This should \@ts-expect-error but does not.
+  expectTypeOf(one).not.toEqualTypeOf(two)
+
+  // The workaround is the new optional .branded modifier.
+  expectTypeOf<{foo: number} & {bar: string}>().branded.toEqualTypeOf<{foo: number; bar: string}>()
+  expectTypeOf(one).branded.toEqualTypeOf(two)
+  // @ts-expect-error
+  expectTypeOf<{foo: number} & {bar: string}>().branded.not.toEqualTypeOf<{foo: number; bar: string}>()
+  // @ts-expect-error
+  expectTypeOf(one).branded.not.toEqualTypeOf(two)
+})
+
+test('Distinguish between identical types that are AND`d together', () => {
+  expectTypeOf<{foo: number} & {foo: number}>().toEqualTypeOf<{foo: number} & {foo: number}>()
+  // Note: The `& T` in `Equal` in index.ts makes this work.
+  expectTypeOf<{foo: number} & {foo: number}>().toEqualTypeOf<{foo: number}>()
+  // @ts-expect-error
+  expectTypeOf<{foo: number} & {foo: number}>().not.toEqualTypeOf<{foo: number} & {foo: number}>()
+  // @ts-expect-error
+  expectTypeOf<{foo: number} & {foo: number}>().not.toEqualTypeOf<{foo: number}>()
+})

From 8944ede5e2def5a4cefb0accaa993d9079f7bfe3 Mon Sep 17 00:00:00 2001
From: Misha Kaletsky <mmkal@users.noreply.github.com>
Date: Thu, 13 Apr 2023 13:38:06 -0400
Subject: [PATCH 2/7] Use options bag

---
 src/index.ts | 90 +++++++++++++++++++++++++++-------------------------
 1 file changed, 47 insertions(+), 43 deletions(-)

diff --git a/src/index.ts b/src/index.ts
index f9733022..1dc0cc91 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -101,64 +101,68 @@ export type ConstructorParams<Actual> = Actual extends new (...args: infer P) =>
     : P
   : never
 
-type MismatchArgs<B extends boolean, C extends boolean> = Eq<B, C> extends true ? [] : [never]
-
-export interface ExpectTypeOf<Actual, B extends boolean, Branded = false> {
-  toBeAny: (...MISMATCH: MismatchArgs<IsAny<Actual>, B>) => true
-  toBeUnknown: (...MISMATCH: MismatchArgs<IsUnknown<Actual>, B>) => true
-  toBeNever: (...MISMATCH: MismatchArgs<IsNever<Actual>, B>) => true
-  toBeFunction: (...MISMATCH: MismatchArgs<Extends<Actual, (...args: any[]) => any>, B>) => true
-  toBeObject: (...MISMATCH: MismatchArgs<Extends<Actual, object>, B>) => true
-  toBeArray: (...MISMATCH: MismatchArgs<Extends<Actual, any[]>, B>) => true
-  toBeNumber: (...MISMATCH: MismatchArgs<Extends<Actual, number>, B>) => true
-  toBeString: (...MISMATCH: MismatchArgs<Extends<Actual, string>, B>) => true
-  toBeBoolean: (...MISMATCH: MismatchArgs<Extends<Actual, boolean>, B>) => true
-  toBeVoid: (...MISMATCH: MismatchArgs<Extends<Actual, void>, B>) => true
-  toBeSymbol: (...MISMATCH: MismatchArgs<Extends<Actual, symbol>, B>) => true
-  toBeNull: (...MISMATCH: MismatchArgs<Extends<Actual, null>, B>) => true
-  toBeUndefined: (...MISMATCH: MismatchArgs<Extends<Actual, undefined>, B>) => true
-  toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Branded>>, B>) => true
+type MismatchArgs<ActualResult extends boolean, ExpectedResult extends boolean> = Eq<ActualResult, ExpectedResult> extends true ? [] : [never]
+
+export interface ExpectTypeOfOptions {
+  positive: boolean
+  branded: boolean
+}
+export interface ExpectTypeOf<Actual, Options extends ExpectTypeOfOptions> {
+  toBeAny: (...MISMATCH: MismatchArgs<IsAny<Actual>, Options['positive']>) => true
+  toBeUnknown: (...MISMATCH: MismatchArgs<IsUnknown<Actual>, Options['positive']>) => true
+  toBeNever: (...MISMATCH: MismatchArgs<IsNever<Actual>, Options['positive']>) => true
+  toBeFunction: (...MISMATCH: MismatchArgs<Extends<Actual, (...args: any[]) => any>, Options['positive']>) => true
+  toBeObject: (...MISMATCH: MismatchArgs<Extends<Actual, object>, Options['positive']>) => true
+  toBeArray: (...MISMATCH: MismatchArgs<Extends<Actual, any[]>, Options['positive']>) => true
+  toBeNumber: (...MISMATCH: MismatchArgs<Extends<Actual, number>, Options['positive']>) => true
+  toBeString: (...MISMATCH: MismatchArgs<Extends<Actual, string>, Options['positive']>) => true
+  toBeBoolean: (...MISMATCH: MismatchArgs<Extends<Actual, boolean>, Options['positive']>) => true
+  toBeVoid: (...MISMATCH: MismatchArgs<Extends<Actual, void>, Options['positive']>) => true
+  toBeSymbol: (...MISMATCH: MismatchArgs<Extends<Actual, symbol>, Options['positive']>) => true
+  toBeNull: (...MISMATCH: MismatchArgs<Extends<Actual, null>, Options['positive']>) => true
+  toBeUndefined: (...MISMATCH: MismatchArgs<Extends<Actual, undefined>, Options['positive']>) => true
+  toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Options['branded']>>, Options['positive']>) => true
   toMatchTypeOf: {
-    <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
-    <Expected>(expected: Expected, ...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
+    <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
+    <Expected>(expected: Expected, ...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
   }
   toEqualTypeOf: {
-    <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
-    <Expected>(expected: Expected, ...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
+    <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+    <Expected>(expected: Expected, ...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
   }
-  toBeCallableWith: B extends true ? (...args: Params<Actual>) => true : never
-  toBeConstructibleWith: B extends true ? (...args: ConstructorParams<Actual>) => true : never
+  toBeCallableWith: Options['positive'] extends true ? (...args: Params<Actual>) => true : never
+  toBeConstructibleWith: Options['positive'] extends true ? (...args: ConstructorParams<Actual>) => true : never
   toHaveProperty: <K extends string>(
     key: K,
-    ...MISMATCH: MismatchArgs<Extends<K, keyof Actual>, B>
-  ) => K extends keyof Actual ? ExpectTypeOf<Actual[K], B, Branded> : true
-  extract: <V>(v?: V) => ExpectTypeOf<Extract<Actual, V>, B, Branded>
-  exclude: <V>(v?: V) => ExpectTypeOf<Exclude<Actual, V>, B, Branded>
-  parameter: <K extends keyof Params<Actual>>(number: K) => ExpectTypeOf<Params<Actual>[K], B, Branded>
-  parameters: ExpectTypeOf<Params<Actual>, B, Branded>
-  constructorParameters: ExpectTypeOf<ConstructorParams<Actual>, B, Branded>
-  thisParameter: ExpectTypeOf<ThisParameterType<Actual>, B, Branded>
-  instance: Actual extends new (...args: any[]) => infer I ? ExpectTypeOf<I, B, Branded> : never
-  returns: Actual extends (...args: any[]) => infer R ? ExpectTypeOf<R, B, Branded> : never
-  resolves: Actual extends PromiseLike<infer R> ? ExpectTypeOf<R, B, Branded> : never
-  items: Actual extends ArrayLike<infer R> ? ExpectTypeOf<R, B, Branded> : never
-  guards: Actual extends (v: any, ...args: any[]) => v is infer T ? ExpectTypeOf<T, B, Branded> : never
+    ...MISMATCH: MismatchArgs<Extends<K, keyof Actual>, Options['positive']>
+  ) => K extends keyof Actual ? ExpectTypeOf<Actual[K], Options> : true
+  extract: <V>(v?: V) => ExpectTypeOf<Extract<Actual, V>, Options>
+  exclude: <V>(v?: V) => ExpectTypeOf<Exclude<Actual, V>, Options>
+  parameter: <K extends keyof Params<Actual>>(number: K) => ExpectTypeOf<Params<Actual>[K], Options>
+  parameters: ExpectTypeOf<Params<Actual>, Options>
+  constructorParameters: ExpectTypeOf<ConstructorParams<Actual>, Options>
+  thisParameter: ExpectTypeOf<ThisParameterType<Actual>, Options>
+  instance: Actual extends new (...args: any[]) => infer I ? ExpectTypeOf<I, Options> : never
+  returns: Actual extends (...args: any[]) => infer R ? ExpectTypeOf<R, Options> : never
+  resolves: Actual extends PromiseLike<infer R> ? ExpectTypeOf<R, Options> : never
+  items: Actual extends ArrayLike<infer R> ? ExpectTypeOf<R, Options> : never
+  guards: Actual extends (v: any, ...args: any[]) => v is infer T ? ExpectTypeOf<T, Options> : never
   asserts: Actual extends (v: any, ...args: any[]) => asserts v is infer T
     ? // Guard methods `(v: any) => asserts v is T` does not actually defines a return type. Thus, any function taking 1 argument matches the signature before.
       // In case the inferred assertion type `R` could not be determined (so, `unknown`), consider the function as a non-guard, and return a `never` type.
       // See https://github.com/microsoft/TypeScript/issues/34636
       unknown extends T
       ? never
-      : ExpectTypeOf<T, B, Branded>
+      : ExpectTypeOf<T, Options>
     : never
-  branded: Omit<ExpectTypeOf<Actual, B, true>, 'branded'>
-  not: Omit<ExpectTypeOf<Actual, Not<B>, Branded>, 'branded'>
+  branded: Omit<ExpectTypeOf<Actual, {positive: Options['positive']; branded: true}>, 'branded'>
+  not: Omit<ExpectTypeOf<Actual, {positive: Not<Options['positive']>; branded: Options['branded']}>, 'not'>
 }
 const fn: any = () => true
 
 export type _ExpectTypeOf = {
-  <Actual>(actual: Actual): ExpectTypeOf<Actual, true>
-  <Actual>(): ExpectTypeOf<Actual, true>
+  <Actual>(actual: Actual): ExpectTypeOf<Actual, {positive: true; branded: false}>
+  <Actual>(): ExpectTypeOf<Actual, {positive: true; branded: false}>
 }
 
 /**
@@ -183,7 +187,7 @@ export type _ExpectTypeOf = {
  * @description
  * See the [full docs](https://npmjs.com/package/expect-type#documentation) for lots more examples.
  */
-export const expectTypeOf: _ExpectTypeOf = <Actual>(_actual?: Actual): ExpectTypeOf<Actual, true> => {
+export const expectTypeOf: _ExpectTypeOf = <Actual>(_actual?: Actual): ExpectTypeOf<Actual, {positive: true; branded: false}> => {
   const nonFunctionProperties = [
     'parameters',
     'returns',
@@ -230,5 +234,5 @@ export const expectTypeOf: _ExpectTypeOf = <Actual>(_actual?: Actual): ExpectTyp
   const getterProperties: readonly Keys[] = nonFunctionProperties
   getterProperties.forEach((prop: Keys) => Object.defineProperty(obj, prop, {get: () => expectTypeOf({})}))
 
-  return obj as ExpectTypeOf<Actual, true>
+  return obj as ExpectTypeOf<Actual, {positive: true, branded: false}>
 }

From bd7275a58222791af20b76c042fef3a5b09dc340 Mon Sep 17 00:00:00 2001
From: Misha Kaletsky <mmkal@users.noreply.github.com>
Date: Thu, 13 Apr 2023 13:38:10 -0400
Subject: [PATCH 3/7] ts-expect-errors

---
 test/types.test.ts | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/test/types.test.ts b/test/types.test.ts
index 8d5c2ce7..23e33fd6 100644
--- a/test/types.test.ts
+++ b/test/types.test.ts
@@ -71,8 +71,10 @@ test(`never types don't sneak by`, () => {
 })
 
 test('intersections work properly', () => {
+  // @ts-expect-error limitation of new implementation
   expectTypeOf<{a: 1} & {b: 2}>().toEqualTypeOf<{a: 1; b: 2}>()
   expectTypeOf<{a: 1} & {b: 2}>().toMatchTypeOf<{a: 1; b: 2}>()
+  // @ts-expect-error limitation of new implementation
   expectTypeOf<{a: 1; b: 2}>().toEqualTypeOf<{a: 1} & {b: 2}>()
   expectTypeOf<{a: 1; b: 2}>().toMatchTypeOf<{a: 1} & {b: 2}>()
 })

From 3081e2edc300d6c3fe1e954617ac4ac21d0d48fc Mon Sep 17 00:00:00 2001
From: Misha Kaletsky <mmkal@users.noreply.github.com>
Date: Thu, 13 Apr 2023 13:48:37 -0400
Subject: [PATCH 4/7] update line numbers in snapshots

---
 test/errors.test.ts | 234 ++++++++++++++++++++++----------------------
 1 file changed, 117 insertions(+), 117 deletions(-)

diff --git a/test/errors.test.ts b/test/errors.test.ts
index 2d3910bc..2723873b 100644
--- a/test/errors.test.ts
+++ b/test/errors.test.ts
@@ -18,9 +18,9 @@ test('toEqualTypeOf<...>() error message', async () => {
     3 expectTypeOf({a: 1}).toEqualTypeOf<{a: string}>()
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:126:16
-        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:130:16
+        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     "
   `)
@@ -43,9 +43,9 @@ test('toMatchTypeOf<...>() error message', async () => {
     3 expectTypeOf({a: 1}).toMatchTypeOf<{a: string}>()
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:122:16
-        122     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:126:16
+        126     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     "
   `)
@@ -58,9 +58,9 @@ test('toMatchTypeOf(...) error message', async () => {
     3 expectTypeOf({a: 1}).toMatchTypeOf({a: 'one'})
                            ~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:123:36
-        123     <Expected>(expected: Expected, ...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
-                                               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:127:36
+        127     <Expected>(expected: Expected, ...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
+                                               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     "
   `)
@@ -86,234 +86,234 @@ test('usage test', () => {
     21   expectTypeOf({a: 1, b: 1}).toEqualTypeOf<{a: number}>()
                                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:126:16
-        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:130:16
+        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:35:25 - error TS2554: Expected 1 arguments, but got 0.
 
     35   expectTypeOf<Fruit>().toMatchTypeOf<Apple>()
                                ~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:122:16
-        122     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:126:16
+        126     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:38:25 - error TS2554: Expected 1 arguments, but got 0.
 
     38   expectTypeOf<Apple>().toEqualTypeOf<Fruit>()
                                ~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:126:16
-        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:130:16
+        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:42:24 - error TS2554: Expected 2 arguments, but got 1.
 
     42   expectTypeOf({a: 1}).toMatchTypeOf({b: 1})
                               ~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:123:36
-        123     <Expected>(expected: Expected, ...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
-                                               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:127:36
+        127     <Expected>(expected: Expected, ...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
+                                               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:51:25 - error TS2554: Expected 1 arguments, but got 0.
 
     51   expectTypeOf<Fruit>().toMatchTypeOf<Apple>()
                                ~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:122:16
-        122     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:126:16
+        126     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:52:25 - error TS2554: Expected 1 arguments, but got 0.
 
     52   expectTypeOf<Apple>().toEqualTypeOf<Fruit>()
                                ~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:126:16
-        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:130:16
+        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:61:25 - error TS2554: Expected 1 arguments, but got 0.
 
     61   expectTypeOf<never>().toBeNumber()
                                ~~~~~~~~~~~~
 
-      src/index.ts:113:16
-        113   toBeNumber: (...MISMATCH: MismatchArgs<Extends<Actual, number>, B>) => true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:117:16
+        117   toBeNumber: (...MISMATCH: MismatchArgs<Extends<Actual, number>, Options['positive']>) => true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:65:43 - error TS2554: Expected 1 arguments, but got 0.
 
     65   expectTypeOf<{deeply: {nested: any}}>().toEqualTypeOf<{deeply: {nested: unknown}}>()
                                                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:126:16
-        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:130:16
+        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:83:27 - error TS2554: Expected 1 arguments, but got 0.
 
     83   expectTypeOf(undefined).toBeNullable()
                                  ~~~~~~~~~~~~~~
 
-      src/index.ts:120:18
-        120   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Branded>>, B>) => true
-                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:124:18
+        124   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Options['branded']>>, Options['positive']>) => true
+                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:87:22 - error TS2554: Expected 1 arguments, but got 0.
 
     87   expectTypeOf(null).toBeNullable()
                             ~~~~~~~~~~~~~~
 
-      src/index.ts:120:18
-        120   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Branded>>, B>) => true
-                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:124:18
+        124   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Options['branded']>>, Options['positive']>) => true
+                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:90:33 - error TS2554: Expected 1 arguments, but got 0.
 
     90   expectTypeOf<1 | undefined>().toBeNullable()
                                        ~~~~~~~~~~~~~~
 
-      src/index.ts:120:18
-        120   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Branded>>, B>) => true
-                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:124:18
+        124   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Options['branded']>>, Options['positive']>) => true
+                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:91:28 - error TS2554: Expected 1 arguments, but got 0.
 
     91   expectTypeOf<1 | null>().toBeNullable()
                                   ~~~~~~~~~~~~~~
 
-      src/index.ts:120:18
-        120   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Branded>>, B>) => true
-                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:124:18
+        124   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Options['branded']>>, Options['positive']>) => true
+                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:92:40 - error TS2554: Expected 1 arguments, but got 0.
 
     92   expectTypeOf<1 | undefined | null>().toBeNullable()
                                               ~~~~~~~~~~~~~~
 
-      src/index.ts:120:18
-        120   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Branded>>, B>) => true
-                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:124:18
+        124   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Options['branded']>>, Options['positive']>) => true
+                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:96:19 - error TS2554: Expected 1 arguments, but got 0.
 
     96   expectTypeOf(1).toBeUnknown()
                          ~~~~~~~~~~~~~
 
-      src/index.ts:108:17
-        108   toBeUnknown: (...MISMATCH: MismatchArgs<IsUnknown<Actual>, B>) => true
-                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:112:17
+        112   toBeUnknown: (...MISMATCH: MismatchArgs<IsUnknown<Actual>, Options['positive']>) => true
+                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:97:19 - error TS2554: Expected 1 arguments, but got 0.
 
     97   expectTypeOf(1).toBeAny()
                          ~~~~~~~~~
 
-      src/index.ts:107:13
-        107   toBeAny: (...MISMATCH: MismatchArgs<IsAny<Actual>, B>) => true
-                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:111:13
+        111   toBeAny: (...MISMATCH: MismatchArgs<IsAny<Actual>, Options['positive']>) => true
+                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:98:19 - error TS2554: Expected 1 arguments, but got 0.
 
     98   expectTypeOf(1).toBeNever()
                          ~~~~~~~~~~~
 
-      src/index.ts:109:15
-        109   toBeNever: (...MISMATCH: MismatchArgs<IsNever<Actual>, B>) => true
-                          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:113:15
+        113   toBeNever: (...MISMATCH: MismatchArgs<IsNever<Actual>, Options['positive']>) => true
+                          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:99:19 - error TS2554: Expected 1 arguments, but got 0.
 
     99   expectTypeOf(1).toBeNull()
                          ~~~~~~~~~~
 
-      src/index.ts:118:14
-        118   toBeNull: (...MISMATCH: MismatchArgs<Extends<Actual, null>, B>) => true
-                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:122:14
+        122   toBeNull: (...MISMATCH: MismatchArgs<Extends<Actual, null>, Options['positive']>) => true
+                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:100:19 - error TS2554: Expected 1 arguments, but got 0.
 
     100   expectTypeOf(1).toBeUndefined()
                           ~~~~~~~~~~~~~~~
 
-      src/index.ts:119:19
-        119   toBeUndefined: (...MISMATCH: MismatchArgs<Extends<Actual, undefined>, B>) => true
-                              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:123:19
+        123   toBeUndefined: (...MISMATCH: MismatchArgs<Extends<Actual, undefined>, Options['positive']>) => true
+                              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:101:19 - error TS2554: Expected 1 arguments, but got 0.
 
     101   expectTypeOf(1).toBeNullable()
                           ~~~~~~~~~~~~~~
 
-      src/index.ts:120:18
-        120   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Branded>>, B>) => true
-                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:124:18
+        124   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Options['branded']>>, Options['positive']>) => true
+                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:106:35 - error TS2554: Expected 1 arguments, but got 0.
 
     106   expectTypeOf<string | number>().toMatchTypeOf<number>()
                                           ~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:122:16
-        122     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:126:16
+        126     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:130:71 - error TS2554: Expected 2 arguments, but got 1.
 
     130   expectTypeOf<ResponsiveProp<number>>().exclude<number | number[]>().toHaveProperty('xxl')
                                                                               ~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:133:5
-        133     ...MISMATCH: MismatchArgs<Extends<K, keyof Actual>, B>
-                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:137:5
+        137     ...MISMATCH: MismatchArgs<Extends<K, keyof Actual>, Options['positive']>
+                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:147:21 - error TS2554: Expected 2 arguments, but got 1.
 
     147   expectTypeOf(obj).toHaveProperty('c')
                             ~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:133:5
-        133     ...MISMATCH: MismatchArgs<Extends<K, keyof Actual>, B>
-                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:137:5
+        137     ...MISMATCH: MismatchArgs<Extends<K, keyof Actual>, Options['positive']>
+                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:152:41 - error TS2554: Expected 1 arguments, but got 0.
 
     152   expectTypeOf(obj).toHaveProperty('a').toBeString()
                                                 ~~~~~~~~~~~~
 
-      src/index.ts:114:16
-        114   toBeString: (...MISMATCH: MismatchArgs<Extends<Actual, string>, B>) => true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:118:16
+        118   toBeString: (...MISMATCH: MismatchArgs<Extends<Actual, string>, Options['positive']>) => true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:159:27 - error TS2554: Expected 1 arguments, but got 0.
 
     159   expectTypeOf<NoParam>().toEqualTypeOf<HasParam>()
                                   ~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:126:16
-        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:130:16
+        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:179:19 - error TS2554: Expected 1 arguments, but got 0.
 
     179   expectTypeOf(f).toBeAny()
                           ~~~~~~~~~
 
-      src/index.ts:107:13
-        107   toBeAny: (...MISMATCH: MismatchArgs<IsAny<Actual>, B>) => true
-                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:111:13
+        111   toBeAny: (...MISMATCH: MismatchArgs<IsAny<Actual>, Options['positive']>) => true
+                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:180:27 - error TS2554: Expected 1 arguments, but got 0.
 
     180   expectTypeOf(f).returns.toBeAny()
                                   ~~~~~~~~~
 
-      src/index.ts:107:13
-        107   toBeAny: (...MISMATCH: MismatchArgs<IsAny<Actual>, B>) => true
-                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:111:13
+        111   toBeAny: (...MISMATCH: MismatchArgs<IsAny<Actual>, Options['positive']>) => true
+                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:183:46 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'never'.
 
@@ -328,90 +328,90 @@ test('usage test', () => {
     246   expectTypeOf([1, 2, 3]).items.toBeString()
                                         ~~~~~~~~~~~~
 
-      src/index.ts:114:16
-        114   toBeString: (...MISMATCH: MismatchArgs<Extends<Actual, string>, B>) => true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:118:16
+        118   toBeString: (...MISMATCH: MismatchArgs<Extends<Actual, string>, Options['positive']>) => true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:258:31 - error TS2554: Expected 1 arguments, but got 0.
 
     258   expectTypeOf<{a: string}>().toEqualTypeOf<{a: number}>()
                                       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:126:16
-        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:130:16
+        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:262:32 - error TS2554: Expected 1 arguments, but got 0.
 
     262   expectTypeOf<{a?: number}>().toEqualTypeOf<{}>()
                                        ~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:126:16
-        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:130:16
+        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:263:32 - error TS2554: Expected 1 arguments, but got 0.
 
     263   expectTypeOf<{a?: number}>().toEqualTypeOf<{a: number}>()
                                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:126:16
-        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:130:16
+        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:264:32 - error TS2554: Expected 1 arguments, but got 0.
 
     264   expectTypeOf<{a?: number}>().toEqualTypeOf<{a: number | undefined}>()
                                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:126:16
-        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:130:16
+        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:265:39 - error TS2554: Expected 1 arguments, but got 0.
 
     265   expectTypeOf<{a?: number | null}>().toEqualTypeOf<{a: number | null}>()
                                               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:126:16
-        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:130:16
+        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:266:37 - error TS2554: Expected 1 arguments, but got 0.
 
     266   expectTypeOf<{a: {b?: number}}>().toEqualTypeOf<{a: {}}>()
                                             ~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:126:16
-        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:130:16
+        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:274:22 - error TS2554: Expected 1 arguments, but got 0.
 
     274   expectTypeOf<A1>().toEqualTypeOf<E1>()
                              ~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:126:16
-        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:130:16
+        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:280:22 - error TS2554: Expected 1 arguments, but got 0.
 
     280   expectTypeOf<A2>().toEqualTypeOf<E2>()
                              ~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:126:16
-        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:130:16
+        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:297:28 - error TS2554: Expected 1 arguments, but got 0.
 
     297   expectTypeOf<typeof A>().toEqualTypeOf<typeof B>()
                                    ~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:126:16
-        126     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Branded>, B>): true
-                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:130:16
+        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     "
   `)

From 5d5b1eba988a49e99547c307bb325f4e30f4711d Mon Sep 17 00:00:00 2001
From: Misha Kaletsky <mmkal@users.noreply.github.com>
Date: Tue, 9 May 2023 23:31:33 -0400
Subject: [PATCH 5/7] Add test for #29

---
 test/usage.test.ts | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/test/usage.test.ts b/test/usage.test.ts
index e1c0e6fe..8d189816 100644
--- a/test/usage.test.ts
+++ b/test/usage.test.ts
@@ -246,6 +246,10 @@ test('Array items can be checked with `.items`', () => {
   expectTypeOf([1, 2, 3]).items.not.toBeString()
 })
 
+test('You can also compare arrays directly', () => {
+  expectTypeOf<any[]>().not.toEqualTypeOf<number[]>()
+})
+
 test('Check that functions never return', () => {
   const thrower = () => {
     throw new Error('oh no')

From f4dab98cda34f5c28e81a827a64f6f59f478f03d Mon Sep 17 00:00:00 2001
From: Misha Kaletsky <mmkal@users.noreply.github.com>
Date: Tue, 9 May 2023 23:42:25 -0400
Subject: [PATCH 6/7] add to readme, update snapshots

---
 README.md           | 22 ++++++++++++++++++
 test/errors.test.ts | 54 ++++++++++++++++++++++++++++++---------------
 test/types.test.ts  |  6 ++---
 test/usage.test.ts  | 12 ++++++++++
 4 files changed, 73 insertions(+), 21 deletions(-)

diff --git a/README.md b/README.md
index f2bb1b16..66c47ca8 100644
--- a/README.md
+++ b/README.md
@@ -351,6 +351,12 @@ expectTypeOf([1, 2, 3]).items.toBeNumber()
 expectTypeOf([1, 2, 3]).items.not.toBeString()
 ```
 
+You can also compare arrays directly:
+
+```typescript
+expectTypeOf<any[]>().not.toEqualTypeOf<number[]>()
+```
+
 Check that functions never return:
 
 ```typescript
@@ -420,6 +426,22 @@ class C {
 
 expectTypeOf<typeof A>().toEqualTypeOf<typeof C>()
 ```
+
+Known limitation: Intersection types can cause issues with `toEqualTypeOf`:
+
+```typescript
+// @ts-expect-error the following line doesn't compile, even though the types are arguably the same.
+// See https://github.com/mmkal/expect-type/pull/21
+expectTypeOf<{a: 1} & {b: 2}>().toEqualTypeOf<{a: 1; b: 2}>()
+```
+
+To workaround, you can use a mapped type:
+
+```typescript
+type Simplify<T> = {[K in keyof T]: T[K]}
+
+expectTypeOf<Simplify<{a: 1} & {b: 2}>>().toEqualTypeOf<{a: 1; b: 2}>()
+```
 <!-- codegen:end -->
 
 ### Within test frameworks
diff --git a/test/errors.test.ts b/test/errors.test.ts
index 2723873b..4fd1261f 100644
--- a/test/errors.test.ts
+++ b/test/errors.test.ts
@@ -332,83 +332,101 @@ test('usage test', () => {
         118   toBeString: (...MISMATCH: MismatchArgs<Extends<Actual, string>, Options['positive']>) => true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
-    test/usage.test.ts:258:31 - error TS2554: Expected 1 arguments, but got 0.
+    test/usage.test.ts:250:25 - error TS2554: Expected 1 arguments, but got 0.
 
-    258   expectTypeOf<{a: string}>().toEqualTypeOf<{a: number}>()
+    250   expectTypeOf<any[]>().toEqualTypeOf<number[]>()
+                                ~~~~~~~~~~~~~~~~~~~~~~~~~
+
+      src/index.ts:130:16
+        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+        Arguments for the rest parameter 'MISMATCH' were not provided.
+    test/usage.test.ts:262:31 - error TS2554: Expected 1 arguments, but got 0.
+
+    262   expectTypeOf<{a: string}>().toEqualTypeOf<{a: number}>()
                                       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
       src/index.ts:130:16
         130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
-    test/usage.test.ts:262:32 - error TS2554: Expected 1 arguments, but got 0.
+    test/usage.test.ts:266:32 - error TS2554: Expected 1 arguments, but got 0.
 
-    262   expectTypeOf<{a?: number}>().toEqualTypeOf<{}>()
+    266   expectTypeOf<{a?: number}>().toEqualTypeOf<{}>()
                                        ~~~~~~~~~~~~~~~~~~~
 
       src/index.ts:130:16
         130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
-    test/usage.test.ts:263:32 - error TS2554: Expected 1 arguments, but got 0.
+    test/usage.test.ts:267:32 - error TS2554: Expected 1 arguments, but got 0.
 
-    263   expectTypeOf<{a?: number}>().toEqualTypeOf<{a: number}>()
+    267   expectTypeOf<{a?: number}>().toEqualTypeOf<{a: number}>()
                                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
       src/index.ts:130:16
         130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
-    test/usage.test.ts:264:32 - error TS2554: Expected 1 arguments, but got 0.
+    test/usage.test.ts:268:32 - error TS2554: Expected 1 arguments, but got 0.
 
-    264   expectTypeOf<{a?: number}>().toEqualTypeOf<{a: number | undefined}>()
+    268   expectTypeOf<{a?: number}>().toEqualTypeOf<{a: number | undefined}>()
                                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
       src/index.ts:130:16
         130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
-    test/usage.test.ts:265:39 - error TS2554: Expected 1 arguments, but got 0.
+    test/usage.test.ts:269:39 - error TS2554: Expected 1 arguments, but got 0.
 
-    265   expectTypeOf<{a?: number | null}>().toEqualTypeOf<{a: number | null}>()
+    269   expectTypeOf<{a?: number | null}>().toEqualTypeOf<{a: number | null}>()
                                               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
       src/index.ts:130:16
         130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
-    test/usage.test.ts:266:37 - error TS2554: Expected 1 arguments, but got 0.
+    test/usage.test.ts:270:37 - error TS2554: Expected 1 arguments, but got 0.
 
-    266   expectTypeOf<{a: {b?: number}}>().toEqualTypeOf<{a: {}}>()
+    270   expectTypeOf<{a: {b?: number}}>().toEqualTypeOf<{a: {}}>()
                                             ~~~~~~~~~~~~~~~~~~~~~~~~
 
       src/index.ts:130:16
         130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
-    test/usage.test.ts:274:22 - error TS2554: Expected 1 arguments, but got 0.
+    test/usage.test.ts:278:22 - error TS2554: Expected 1 arguments, but got 0.
 
-    274   expectTypeOf<A1>().toEqualTypeOf<E1>()
+    278   expectTypeOf<A1>().toEqualTypeOf<E1>()
                              ~~~~~~~~~~~~~~~~~~~
 
       src/index.ts:130:16
         130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
-    test/usage.test.ts:280:22 - error TS2554: Expected 1 arguments, but got 0.
+    test/usage.test.ts:284:22 - error TS2554: Expected 1 arguments, but got 0.
 
-    280   expectTypeOf<A2>().toEqualTypeOf<E2>()
+    284   expectTypeOf<A2>().toEqualTypeOf<E2>()
                              ~~~~~~~~~~~~~~~~~~~
 
       src/index.ts:130:16
         130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
-    test/usage.test.ts:297:28 - error TS2554: Expected 1 arguments, but got 0.
+    test/usage.test.ts:301:28 - error TS2554: Expected 1 arguments, but got 0.
 
-    297   expectTypeOf<typeof A>().toEqualTypeOf<typeof B>()
+    301   expectTypeOf<typeof A>().toEqualTypeOf<typeof B>()
                                    ~~~~~~~~~~~~~~~~~~~~~~~~~
 
+      src/index.ts:130:16
+        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+        Arguments for the rest parameter 'MISMATCH' were not provided.
+    test/usage.test.ts:316:35 - error TS2554: Expected 1 arguments, but got 0.
+
+    316   expectTypeOf<{a: 1} & {b: 2}>().toEqualTypeOf<{a: 1; b: 2}>()
+                                          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
       src/index.ts:130:16
         130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/test/types.test.ts b/test/types.test.ts
index 9825678a..2e57ed4f 100644
--- a/test/types.test.ts
+++ b/test/types.test.ts
@@ -70,11 +70,11 @@ test(`never types don't sneak by`, () => {
   expectTypeOf<never>().toMatchTypeOf<{foo: string}>()
 })
 
-test('intersections work properly', () => {
-  // @ts-expect-error limitation of new implementation
+test('intersections do not currently work properly', () => {
+  // @ts-expect-error limitation of new implementation https://github.com/mmkal/expect-type/pull/21
   expectTypeOf<{a: 1} & {b: 2}>().toEqualTypeOf<{a: 1; b: 2}>()
   expectTypeOf<{a: 1} & {b: 2}>().toMatchTypeOf<{a: 1; b: 2}>()
-  // @ts-expect-error limitation of new implementation
+  // @ts-expect-error limitation of new implementation https://github.com/mmkal/expect-type/pull/21
   expectTypeOf<{a: 1; b: 2}>().toEqualTypeOf<{a: 1} & {b: 2}>()
   expectTypeOf<{a: 1; b: 2}>().toMatchTypeOf<{a: 1} & {b: 2}>()
 })
diff --git a/test/usage.test.ts b/test/usage.test.ts
index 8d189816..950fd303 100644
--- a/test/usage.test.ts
+++ b/test/usage.test.ts
@@ -309,3 +309,15 @@ test('Distinguish between classes with different constructors', () => {
 
   expectTypeOf<typeof A>().toEqualTypeOf<typeof C>()
 })
+
+test('Known limitation: Intersection types can cause issues with `toEqualTypeOf`', () => {
+  // @ts-expect-error the following line doesn't compile, even though the types are arguably the same.
+  // See https://github.com/mmkal/expect-type/pull/21
+  expectTypeOf<{a: 1} & {b: 2}>().toEqualTypeOf<{a: 1; b: 2}>()
+})
+
+test('To workaround, you can use a mapped type', () => {
+  type Simplify<T> = {[K in keyof T]: T[K]}
+
+  expectTypeOf<Simplify<{a: 1} & {b: 2}>>().toEqualTypeOf<{a: 1; b: 2}>()
+})

From 241e1e57ffa2e5f09822837f648ffb3bb9d4fabf Mon Sep 17 00:00:00 2001
From: Misha Kaletsky <mmkal@users.noreply.github.com>
Date: Tue, 9 May 2023 23:44:14 -0400
Subject: [PATCH 7/7] prettier?

---
 src/index.ts        |  42 +++++++----
 test/errors.test.ts | 176 ++++++++++++++++++++++----------------------
 2 files changed, 116 insertions(+), 102 deletions(-)

diff --git a/src/index.ts b/src/index.ts
index 1dc0cc91..ded80201 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -84,15 +84,17 @@ type ReadonlyEquivalent<X, Y> = Extends<
 export type Extends<L, R> = IsNever<L> extends true ? IsNever<R> : [L] extends [R] ? true : false
 export type StrictExtends<L, R> = Extends<DeepBrand<L>, DeepBrand<R>>
 
-type StrictEqual<L, R> =
-  (<T>() => T extends (L & T) | T ? true : false) extends
-  (<T>() => T extends (R & T) | T ? true : false) ?
-    IsNever<L> extends IsNever<R> ? true : false : false
-
-export type Equal<Left, Right, Branded = true> =
-  Branded extends true
-    ? And<[StrictExtends<Left, Right>, StrictExtends<Right, Left>]>
-    : StrictEqual<Left, Right>
+type StrictEqual<L, R> = (<T>() => T extends (L & T) | T ? true : false) extends <T>() => T extends (R & T) | T
+  ? true
+  : false
+  ? IsNever<L> extends IsNever<R>
+    ? true
+    : false
+  : false
+
+export type Equal<Left, Right, Branded = true> = Branded extends true
+  ? And<[StrictExtends<Left, Right>, StrictExtends<Right, Left>]>
+  : StrictEqual<Left, Right>
 
 export type Params<Actual> = Actual extends (...args: infer P) => any ? P : never
 export type ConstructorParams<Actual> = Actual extends new (...args: infer P) => any
@@ -101,7 +103,12 @@ export type ConstructorParams<Actual> = Actual extends new (...args: infer P) =>
     : P
   : never
 
-type MismatchArgs<ActualResult extends boolean, ExpectedResult extends boolean> = Eq<ActualResult, ExpectedResult> extends true ? [] : [never]
+type MismatchArgs<ActualResult extends boolean, ExpectedResult extends boolean> = Eq<
+  ActualResult,
+  ExpectedResult
+> extends true
+  ? []
+  : [never]
 
 export interface ExpectTypeOfOptions {
   positive: boolean
@@ -121,14 +128,19 @@ export interface ExpectTypeOf<Actual, Options extends ExpectTypeOfOptions> {
   toBeSymbol: (...MISMATCH: MismatchArgs<Extends<Actual, symbol>, Options['positive']>) => true
   toBeNull: (...MISMATCH: MismatchArgs<Extends<Actual, null>, Options['positive']>) => true
   toBeUndefined: (...MISMATCH: MismatchArgs<Extends<Actual, undefined>, Options['positive']>) => true
-  toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Options['branded']>>, Options['positive']>) => true
+  toBeNullable: (
+    ...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Options['branded']>>, Options['positive']>
+  ) => true
   toMatchTypeOf: {
     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
     <Expected>(expected: Expected, ...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
   }
   toEqualTypeOf: {
     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
-    <Expected>(expected: Expected, ...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+    <Expected>(
+      expected: Expected,
+      ...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>
+    ): true
   }
   toBeCallableWith: Options['positive'] extends true ? (...args: Params<Actual>) => true : never
   toBeConstructibleWith: Options['positive'] extends true ? (...args: ConstructorParams<Actual>) => true : never
@@ -187,7 +199,9 @@ export type _ExpectTypeOf = {
  * @description
  * See the [full docs](https://npmjs.com/package/expect-type#documentation) for lots more examples.
  */
-export const expectTypeOf: _ExpectTypeOf = <Actual>(_actual?: Actual): ExpectTypeOf<Actual, {positive: true; branded: false}> => {
+export const expectTypeOf: _ExpectTypeOf = <Actual>(
+  _actual?: Actual,
+): ExpectTypeOf<Actual, {positive: true; branded: false}> => {
   const nonFunctionProperties = [
     'parameters',
     'returns',
@@ -234,5 +248,5 @@ export const expectTypeOf: _ExpectTypeOf = <Actual>(_actual?: Actual): ExpectTyp
   const getterProperties: readonly Keys[] = nonFunctionProperties
   getterProperties.forEach((prop: Keys) => Object.defineProperty(obj, prop, {get: () => expectTypeOf({})}))
 
-  return obj as ExpectTypeOf<Actual, {positive: true, branded: false}>
+  return obj as ExpectTypeOf<Actual, {positive: true; branded: false}>
 }
diff --git a/test/errors.test.ts b/test/errors.test.ts
index 4fd1261f..755b5cfa 100644
--- a/test/errors.test.ts
+++ b/test/errors.test.ts
@@ -18,8 +18,8 @@ test('toEqualTypeOf<...>() error message', async () => {
     3 expectTypeOf({a: 1}).toEqualTypeOf<{a: string}>()
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:130:16
-        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+      src/index.ts:139:16
+        139     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     "
@@ -43,8 +43,8 @@ test('toMatchTypeOf<...>() error message', async () => {
     3 expectTypeOf({a: 1}).toMatchTypeOf<{a: string}>()
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:126:16
-        126     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
+      src/index.ts:135:16
+        135     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     "
@@ -58,8 +58,8 @@ test('toMatchTypeOf(...) error message', async () => {
     3 expectTypeOf({a: 1}).toMatchTypeOf({a: 'one'})
                            ~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:127:36
-        127     <Expected>(expected: Expected, ...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
+      src/index.ts:136:36
+        136     <Expected>(expected: Expected, ...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
                                                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     "
@@ -86,8 +86,8 @@ test('usage test', () => {
     21   expectTypeOf({a: 1, b: 1}).toEqualTypeOf<{a: number}>()
                                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:130:16
-        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+      src/index.ts:139:16
+        139     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:35:25 - error TS2554: Expected 1 arguments, but got 0.
@@ -95,8 +95,8 @@ test('usage test', () => {
     35   expectTypeOf<Fruit>().toMatchTypeOf<Apple>()
                                ~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:126:16
-        126     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
+      src/index.ts:135:16
+        135     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:38:25 - error TS2554: Expected 1 arguments, but got 0.
@@ -104,8 +104,8 @@ test('usage test', () => {
     38   expectTypeOf<Apple>().toEqualTypeOf<Fruit>()
                                ~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:130:16
-        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+      src/index.ts:139:16
+        139     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:42:24 - error TS2554: Expected 2 arguments, but got 1.
@@ -113,8 +113,8 @@ test('usage test', () => {
     42   expectTypeOf({a: 1}).toMatchTypeOf({b: 1})
                               ~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:127:36
-        127     <Expected>(expected: Expected, ...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
+      src/index.ts:136:36
+        136     <Expected>(expected: Expected, ...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
                                                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:51:25 - error TS2554: Expected 1 arguments, but got 0.
@@ -122,8 +122,8 @@ test('usage test', () => {
     51   expectTypeOf<Fruit>().toMatchTypeOf<Apple>()
                                ~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:126:16
-        126     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
+      src/index.ts:135:16
+        135     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:52:25 - error TS2554: Expected 1 arguments, but got 0.
@@ -131,8 +131,8 @@ test('usage test', () => {
     52   expectTypeOf<Apple>().toEqualTypeOf<Fruit>()
                                ~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:130:16
-        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+      src/index.ts:139:16
+        139     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:61:25 - error TS2554: Expected 1 arguments, but got 0.
@@ -140,8 +140,8 @@ test('usage test', () => {
     61   expectTypeOf<never>().toBeNumber()
                                ~~~~~~~~~~~~
 
-      src/index.ts:117:16
-        117   toBeNumber: (...MISMATCH: MismatchArgs<Extends<Actual, number>, Options['positive']>) => true
+      src/index.ts:124:16
+        124   toBeNumber: (...MISMATCH: MismatchArgs<Extends<Actual, number>, Options['positive']>) => true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:65:43 - error TS2554: Expected 1 arguments, but got 0.
@@ -149,8 +149,8 @@ test('usage test', () => {
     65   expectTypeOf<{deeply: {nested: any}}>().toEqualTypeOf<{deeply: {nested: unknown}}>()
                                                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:130:16
-        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+      src/index.ts:139:16
+        139     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:83:27 - error TS2554: Expected 1 arguments, but got 0.
@@ -158,53 +158,53 @@ test('usage test', () => {
     83   expectTypeOf(undefined).toBeNullable()
                                  ~~~~~~~~~~~~~~
 
-      src/index.ts:124:18
-        124   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Options['branded']>>, Options['positive']>) => true
-                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:132:5
+        132     ...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Options['branded']>>, Options['positive']>
+                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:87:22 - error TS2554: Expected 1 arguments, but got 0.
 
     87   expectTypeOf(null).toBeNullable()
                             ~~~~~~~~~~~~~~
 
-      src/index.ts:124:18
-        124   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Options['branded']>>, Options['positive']>) => true
-                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:132:5
+        132     ...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Options['branded']>>, Options['positive']>
+                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:90:33 - error TS2554: Expected 1 arguments, but got 0.
 
     90   expectTypeOf<1 | undefined>().toBeNullable()
                                        ~~~~~~~~~~~~~~
 
-      src/index.ts:124:18
-        124   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Options['branded']>>, Options['positive']>) => true
-                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:132:5
+        132     ...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Options['branded']>>, Options['positive']>
+                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:91:28 - error TS2554: Expected 1 arguments, but got 0.
 
     91   expectTypeOf<1 | null>().toBeNullable()
                                   ~~~~~~~~~~~~~~
 
-      src/index.ts:124:18
-        124   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Options['branded']>>, Options['positive']>) => true
-                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:132:5
+        132     ...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Options['branded']>>, Options['positive']>
+                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:92:40 - error TS2554: Expected 1 arguments, but got 0.
 
     92   expectTypeOf<1 | undefined | null>().toBeNullable()
                                               ~~~~~~~~~~~~~~
 
-      src/index.ts:124:18
-        124   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Options['branded']>>, Options['positive']>) => true
-                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:132:5
+        132     ...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Options['branded']>>, Options['positive']>
+                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:96:19 - error TS2554: Expected 1 arguments, but got 0.
 
     96   expectTypeOf(1).toBeUnknown()
                          ~~~~~~~~~~~~~
 
-      src/index.ts:112:17
-        112   toBeUnknown: (...MISMATCH: MismatchArgs<IsUnknown<Actual>, Options['positive']>) => true
+      src/index.ts:119:17
+        119   toBeUnknown: (...MISMATCH: MismatchArgs<IsUnknown<Actual>, Options['positive']>) => true
                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:97:19 - error TS2554: Expected 1 arguments, but got 0.
@@ -212,8 +212,8 @@ test('usage test', () => {
     97   expectTypeOf(1).toBeAny()
                          ~~~~~~~~~
 
-      src/index.ts:111:13
-        111   toBeAny: (...MISMATCH: MismatchArgs<IsAny<Actual>, Options['positive']>) => true
+      src/index.ts:118:13
+        118   toBeAny: (...MISMATCH: MismatchArgs<IsAny<Actual>, Options['positive']>) => true
                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:98:19 - error TS2554: Expected 1 arguments, but got 0.
@@ -221,8 +221,8 @@ test('usage test', () => {
     98   expectTypeOf(1).toBeNever()
                          ~~~~~~~~~~~
 
-      src/index.ts:113:15
-        113   toBeNever: (...MISMATCH: MismatchArgs<IsNever<Actual>, Options['positive']>) => true
+      src/index.ts:120:15
+        120   toBeNever: (...MISMATCH: MismatchArgs<IsNever<Actual>, Options['positive']>) => true
                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:99:19 - error TS2554: Expected 1 arguments, but got 0.
@@ -230,8 +230,8 @@ test('usage test', () => {
     99   expectTypeOf(1).toBeNull()
                          ~~~~~~~~~~
 
-      src/index.ts:122:14
-        122   toBeNull: (...MISMATCH: MismatchArgs<Extends<Actual, null>, Options['positive']>) => true
+      src/index.ts:129:14
+        129   toBeNull: (...MISMATCH: MismatchArgs<Extends<Actual, null>, Options['positive']>) => true
                          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:100:19 - error TS2554: Expected 1 arguments, but got 0.
@@ -239,8 +239,8 @@ test('usage test', () => {
     100   expectTypeOf(1).toBeUndefined()
                           ~~~~~~~~~~~~~~~
 
-      src/index.ts:123:19
-        123   toBeUndefined: (...MISMATCH: MismatchArgs<Extends<Actual, undefined>, Options['positive']>) => true
+      src/index.ts:130:19
+        130   toBeUndefined: (...MISMATCH: MismatchArgs<Extends<Actual, undefined>, Options['positive']>) => true
                               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:101:19 - error TS2554: Expected 1 arguments, but got 0.
@@ -248,17 +248,17 @@ test('usage test', () => {
     101   expectTypeOf(1).toBeNullable()
                           ~~~~~~~~~~~~~~
 
-      src/index.ts:124:18
-        124   toBeNullable: (...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Options['branded']>>, Options['positive']>) => true
-                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+      src/index.ts:132:5
+        132     ...MISMATCH: MismatchArgs<Not<Equal<Actual, NonNullable<Actual>, Options['branded']>>, Options['positive']>
+                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:106:35 - error TS2554: Expected 1 arguments, but got 0.
 
     106   expectTypeOf<string | number>().toMatchTypeOf<number>()
                                           ~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:126:16
-        126     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
+      src/index.ts:135:16
+        135     <Expected>(...MISMATCH: MismatchArgs<Extends<Actual, Expected>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:130:71 - error TS2554: Expected 2 arguments, but got 1.
@@ -266,8 +266,8 @@ test('usage test', () => {
     130   expectTypeOf<ResponsiveProp<number>>().exclude<number | number[]>().toHaveProperty('xxl')
                                                                               ~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:137:5
-        137     ...MISMATCH: MismatchArgs<Extends<K, keyof Actual>, Options['positive']>
+      src/index.ts:149:5
+        149     ...MISMATCH: MismatchArgs<Extends<K, keyof Actual>, Options['positive']>
                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:147:21 - error TS2554: Expected 2 arguments, but got 1.
@@ -275,8 +275,8 @@ test('usage test', () => {
     147   expectTypeOf(obj).toHaveProperty('c')
                             ~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:137:5
-        137     ...MISMATCH: MismatchArgs<Extends<K, keyof Actual>, Options['positive']>
+      src/index.ts:149:5
+        149     ...MISMATCH: MismatchArgs<Extends<K, keyof Actual>, Options['positive']>
                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:152:41 - error TS2554: Expected 1 arguments, but got 0.
@@ -284,8 +284,8 @@ test('usage test', () => {
     152   expectTypeOf(obj).toHaveProperty('a').toBeString()
                                                 ~~~~~~~~~~~~
 
-      src/index.ts:118:16
-        118   toBeString: (...MISMATCH: MismatchArgs<Extends<Actual, string>, Options['positive']>) => true
+      src/index.ts:125:16
+        125   toBeString: (...MISMATCH: MismatchArgs<Extends<Actual, string>, Options['positive']>) => true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:159:27 - error TS2554: Expected 1 arguments, but got 0.
@@ -293,8 +293,8 @@ test('usage test', () => {
     159   expectTypeOf<NoParam>().toEqualTypeOf<HasParam>()
                                   ~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:130:16
-        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+      src/index.ts:139:16
+        139     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:179:19 - error TS2554: Expected 1 arguments, but got 0.
@@ -302,8 +302,8 @@ test('usage test', () => {
     179   expectTypeOf(f).toBeAny()
                           ~~~~~~~~~
 
-      src/index.ts:111:13
-        111   toBeAny: (...MISMATCH: MismatchArgs<IsAny<Actual>, Options['positive']>) => true
+      src/index.ts:118:13
+        118   toBeAny: (...MISMATCH: MismatchArgs<IsAny<Actual>, Options['positive']>) => true
                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:180:27 - error TS2554: Expected 1 arguments, but got 0.
@@ -311,8 +311,8 @@ test('usage test', () => {
     180   expectTypeOf(f).returns.toBeAny()
                                   ~~~~~~~~~
 
-      src/index.ts:111:13
-        111   toBeAny: (...MISMATCH: MismatchArgs<IsAny<Actual>, Options['positive']>) => true
+      src/index.ts:118:13
+        118   toBeAny: (...MISMATCH: MismatchArgs<IsAny<Actual>, Options['positive']>) => true
                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:183:46 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'never'.
@@ -328,8 +328,8 @@ test('usage test', () => {
     246   expectTypeOf([1, 2, 3]).items.toBeString()
                                         ~~~~~~~~~~~~
 
-      src/index.ts:118:16
-        118   toBeString: (...MISMATCH: MismatchArgs<Extends<Actual, string>, Options['positive']>) => true
+      src/index.ts:125:16
+        125   toBeString: (...MISMATCH: MismatchArgs<Extends<Actual, string>, Options['positive']>) => true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:250:25 - error TS2554: Expected 1 arguments, but got 0.
@@ -337,8 +337,8 @@ test('usage test', () => {
     250   expectTypeOf<any[]>().toEqualTypeOf<number[]>()
                                 ~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:130:16
-        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+      src/index.ts:139:16
+        139     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:262:31 - error TS2554: Expected 1 arguments, but got 0.
@@ -346,8 +346,8 @@ test('usage test', () => {
     262   expectTypeOf<{a: string}>().toEqualTypeOf<{a: number}>()
                                       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:130:16
-        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+      src/index.ts:139:16
+        139     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:266:32 - error TS2554: Expected 1 arguments, but got 0.
@@ -355,8 +355,8 @@ test('usage test', () => {
     266   expectTypeOf<{a?: number}>().toEqualTypeOf<{}>()
                                        ~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:130:16
-        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+      src/index.ts:139:16
+        139     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:267:32 - error TS2554: Expected 1 arguments, but got 0.
@@ -364,8 +364,8 @@ test('usage test', () => {
     267   expectTypeOf<{a?: number}>().toEqualTypeOf<{a: number}>()
                                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:130:16
-        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+      src/index.ts:139:16
+        139     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:268:32 - error TS2554: Expected 1 arguments, but got 0.
@@ -373,8 +373,8 @@ test('usage test', () => {
     268   expectTypeOf<{a?: number}>().toEqualTypeOf<{a: number | undefined}>()
                                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:130:16
-        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+      src/index.ts:139:16
+        139     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:269:39 - error TS2554: Expected 1 arguments, but got 0.
@@ -382,8 +382,8 @@ test('usage test', () => {
     269   expectTypeOf<{a?: number | null}>().toEqualTypeOf<{a: number | null}>()
                                               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:130:16
-        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+      src/index.ts:139:16
+        139     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:270:37 - error TS2554: Expected 1 arguments, but got 0.
@@ -391,8 +391,8 @@ test('usage test', () => {
     270   expectTypeOf<{a: {b?: number}}>().toEqualTypeOf<{a: {}}>()
                                             ~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:130:16
-        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+      src/index.ts:139:16
+        139     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:278:22 - error TS2554: Expected 1 arguments, but got 0.
@@ -400,8 +400,8 @@ test('usage test', () => {
     278   expectTypeOf<A1>().toEqualTypeOf<E1>()
                              ~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:130:16
-        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+      src/index.ts:139:16
+        139     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:284:22 - error TS2554: Expected 1 arguments, but got 0.
@@ -409,8 +409,8 @@ test('usage test', () => {
     284   expectTypeOf<A2>().toEqualTypeOf<E2>()
                              ~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:130:16
-        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+      src/index.ts:139:16
+        139     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:301:28 - error TS2554: Expected 1 arguments, but got 0.
@@ -418,8 +418,8 @@ test('usage test', () => {
     301   expectTypeOf<typeof A>().toEqualTypeOf<typeof B>()
                                    ~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:130:16
-        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+      src/index.ts:139:16
+        139     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     test/usage.test.ts:316:35 - error TS2554: Expected 1 arguments, but got 0.
@@ -427,8 +427,8 @@ test('usage test', () => {
     316   expectTypeOf<{a: 1} & {b: 2}>().toEqualTypeOf<{a: 1; b: 2}>()
                                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      src/index.ts:130:16
-        130     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
+      src/index.ts:139:16
+        139     <Expected>(...MISMATCH: MismatchArgs<Equal<Actual, Expected, Options['branded']>, Options['positive']>): true
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         Arguments for the rest parameter 'MISMATCH' were not provided.
     "