check usage before declaration for decorators

src/compiler/checker.ts

@@ -3068,13 +3068,17 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             return isForInOrOfStatement(grandparent) && isSameScopeDescendentOf(usage, grandparent.expression, declContainer);
         }
 
-        function isUsedInFunctionOrInstanceProperty(usage: Node, declaration: Node): boolean {
+        function isUsedInFunctionOrInstanceProperty(usage: Node, declaration: Node) {
+            return isUsedInFunctionOrInstancePropertyWorker(usage, declaration);
+        }
+
+        function isUsedInFunctionOrInstancePropertyWorker(usage: Node, declaration: Node): boolean {
             return !!findAncestor(usage, current => {
                 if (current === declContainer) {
                     return "quit";
                 }
                 if (isFunctionLike(current)) {
-                    return true;
+                    return !getImmediatelyInvokedFunctionExpression(current);
                 }
                 if (isClassStaticBlockDeclaration(current)) {
                     return declaration.pos < usage.pos;
@@ -3107,6 +3111,17 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                         }
                     }
                 }
+
+                const decorator = tryCast(current.parent, isDecorator);
+                if (decorator && decorator.expression === current) {
+                    if (isParameter(decorator.parent)) {
+                        return isUsedInFunctionOrInstancePropertyWorker(decorator.parent.parent.parent, declaration) ? true : "quit";
+                    }
+                    if (isMethodDeclaration(decorator.parent)) {
+                        return isUsedInFunctionOrInstancePropertyWorker(decorator.parent.parent, declaration) ? true : "quit";
+                    }
+                }
+
                 return false;
             });
         }

tests/baselines/reference/blockScopedVariablesUseBeforeDef.errors.txt

@@ -5,9 +5,12 @@ blockScopedVariablesUseBeforeDef.ts(100,12): error TS2448: Block-scoped variable
 blockScopedVariablesUseBeforeDef.ts(111,28): error TS2448: Block-scoped variable 'a' used before its declaration.
 blockScopedVariablesUseBeforeDef.ts(112,21): error TS2448: Block-scoped variable 'a' used before its declaration.
 blockScopedVariablesUseBeforeDef.ts(122,22): error TS2448: Block-scoped variable 'a' used before its declaration.
+blockScopedVariablesUseBeforeDef.ts(128,9): error TS2448: Block-scoped variable 'foo' used before its declaration.
+blockScopedVariablesUseBeforeDef.ts(131,9): error TS2448: Block-scoped variable 'foo' used before its declaration.
+blockScopedVariablesUseBeforeDef.ts(153,20): error TS2450: Enum 'Enum' used before its declaration.
 
 
-==== blockScopedVariablesUseBeforeDef.ts (7 errors) ====
+==== blockScopedVariablesUseBeforeDef.ts (10 errors) ====
     function foo0() {
         let a = x;
                 ~
@@ -157,9 +160,15 @@ blockScopedVariablesUseBeforeDef.ts(122,22): error TS2448: Block-scoped variable
         const promise = (async () => {
             promise
             foo
+            ~~~
+!!! error TS2448: Block-scoped variable 'foo' used before its declaration.
+!!! related TS2728 blockScopedVariablesUseBeforeDef.ts:134:11: 'foo' is declared here.
             await null
             promise
             foo
+            ~~~
+!!! error TS2448: Block-scoped variable 'foo' used before its declaration.
+!!! related TS2728 blockScopedVariablesUseBeforeDef.ts:134:11: 'foo' is declared here.
         })()
 
         const foo = 1;
@@ -179,4 +188,15 @@ blockScopedVariablesUseBeforeDef.ts(122,22): error TS2448: Block-scoped variable
             yield 1;
         })();
     }
+
+    function foo18() {
+        let a = (() => Enum.Yes)();
+                       ~~~~
+!!! error TS2450: Enum 'Enum' used before its declaration.
+!!! related TS2728 blockScopedVariablesUseBeforeDef.ts:154:10: 'Enum' is declared here.
+        enum Enum {
+            No = 0,
+            Yes = 1,
+        }
+    }
 

tests/baselines/reference/blockScopedVariablesUseBeforeDef.js

@@ -151,6 +151,14 @@ function wrapI2() {
         yield 1;
     })();
 }
+
+function foo18() {
+    let a = (() => Enum.Yes)();
+    enum Enum {
+        No = 0,
+        Yes = 1,
+    }
+}
 
 
 //// [blockScopedVariablesUseBeforeDef.js]
@@ -389,3 +397,11 @@ function wrapI2() {
         });
     })();
 }
+function foo18() {
+    var a = (function () { return Enum.Yes; })();
+    var Enum;
+    (function (Enum) {
+        Enum[Enum["No"] = 0] = "No";
+        Enum[Enum["Yes"] = 1] = "Yes";
+    })(Enum || (Enum = {}));
+}

tests/baselines/reference/blockScopedVariablesUseBeforeDef.symbols

@@ -312,3 +312,23 @@ function wrapI2() {
     })();
 }
 
+function foo18() {
+>foo18 : Symbol(foo18, Decl(blockScopedVariablesUseBeforeDef.ts, 149, 1))
+
+    let a = (() => Enum.Yes)();
+>a : Symbol(a, Decl(blockScopedVariablesUseBeforeDef.ts, 152, 7))
+>Enum.Yes : Symbol(Enum.Yes, Decl(blockScopedVariablesUseBeforeDef.ts, 154, 15))
+>Enum : Symbol(Enum, Decl(blockScopedVariablesUseBeforeDef.ts, 152, 31))
+>Yes : Symbol(Enum.Yes, Decl(blockScopedVariablesUseBeforeDef.ts, 154, 15))
+
+    enum Enum {
+>Enum : Symbol(Enum, Decl(blockScopedVariablesUseBeforeDef.ts, 152, 31))
+
+        No = 0,
+>No : Symbol(Enum.No, Decl(blockScopedVariablesUseBeforeDef.ts, 153, 15))
+
+        Yes = 1,
+>Yes : Symbol(Enum.Yes, Decl(blockScopedVariablesUseBeforeDef.ts, 154, 15))
+    }
+}
+

tests/baselines/reference/blockScopedVariablesUseBeforeDef.types

@@ -510,3 +510,41 @@ function wrapI2() {
     })();
 }
 
+function foo18() {
+>foo18 : () => void
+>      : ^^^^^^^^^^
+
+    let a = (() => Enum.Yes)();
+>a : Enum
+>  : ^^^^
+>(() => Enum.Yes)() : Enum
+>                   : ^^^^
+>(() => Enum.Yes) : () => Enum
+>                 : ^^^^^^^^^^
+>() => Enum.Yes : () => Enum
+>               : ^^^^^^^^^^
+>Enum.Yes : Enum.Yes
+>         : ^^^^^^^^
+>Enum : typeof Enum
+>     : ^^^^^^^^^^^
+>Yes : Enum.Yes
+>    : ^^^^^^^^
+
+    enum Enum {
+>Enum : Enum
+>     : ^^^^
+
+        No = 0,
+>No : Enum.No
+>   : ^^^^^^^
+>0 : 0
+>  : ^
+
+        Yes = 1,
+>Yes : Enum.Yes
+>    : ^^^^^^^^
+>1 : 1
+>  : ^
+    }
+}
+

tests/baselines/reference/decoratorUsedBeforeDeclaration.errors.txt

@@ -0,0 +1,140 @@
+decoratorUsedBeforeDeclaration.ts(1,2): error TS2448: Block-scoped variable 'lambda' used before its declaration.
+decoratorUsedBeforeDeclaration.ts(1,9): error TS2450: Enum 'Enum' used before its declaration.
+decoratorUsedBeforeDeclaration.ts(2,7): error TS2450: Enum 'Enum' used before its declaration.
+decoratorUsedBeforeDeclaration.ts(4,4): error TS2448: Block-scoped variable 'lambda' used before its declaration.
+decoratorUsedBeforeDeclaration.ts(4,11): error TS2450: Enum 'Enum' used before its declaration.
+decoratorUsedBeforeDeclaration.ts(4,16): error TS2729: Property 'No' is used before its initialization.
+decoratorUsedBeforeDeclaration.ts(5,9): error TS2450: Enum 'Enum' used before its declaration.
+decoratorUsedBeforeDeclaration.ts(5,14): error TS2729: Property 'No' is used before its initialization.
+decoratorUsedBeforeDeclaration.ts(12,4): error TS2448: Block-scoped variable 'lambda' used before its declaration.
+decoratorUsedBeforeDeclaration.ts(12,11): error TS2450: Enum 'Enum' used before its declaration.
+decoratorUsedBeforeDeclaration.ts(13,9): error TS2450: Enum 'Enum' used before its declaration.
+decoratorUsedBeforeDeclaration.ts(18,4): error TS2448: Block-scoped variable 'lambda' used before its declaration.
+decoratorUsedBeforeDeclaration.ts(24,11): error TS2448: Block-scoped variable 'lambda' used before its declaration.
+decoratorUsedBeforeDeclaration.ts(24,18): error TS2450: Enum 'Enum' used before its declaration.
+decoratorUsedBeforeDeclaration.ts(24,33): error TS2450: Enum 'Enum' used before its declaration.
+decoratorUsedBeforeDeclaration.ts(28,11): error TS2448: Block-scoped variable 'lambda' used before its declaration.
+
+
+==== decoratorUsedBeforeDeclaration.ts (16 errors) ====
+    @lambda(Enum.No)
+     ~~~~~~
+!!! error TS2448: Block-scoped variable 'lambda' used before its declaration.
+!!! related TS2728 decoratorUsedBeforeDeclaration.ts:40:7: 'lambda' is declared here.
+            ~~~~
+!!! error TS2450: Enum 'Enum' used before its declaration.
+!!! related TS2728 decoratorUsedBeforeDeclaration.ts:35:6: 'Enum' is declared here.
+    @deco(Enum.No)
+          ~~~~
+!!! error TS2450: Enum 'Enum' used before its declaration.
+!!! related TS2728 decoratorUsedBeforeDeclaration.ts:35:6: 'Enum' is declared here.
+    class Greeter {
+      @lambda(Enum.No)
+       ~~~~~~
+!!! error TS2448: Block-scoped variable 'lambda' used before its declaration.
+!!! related TS2728 decoratorUsedBeforeDeclaration.ts:40:7: 'lambda' is declared here.
+              ~~~~
+!!! error TS2450: Enum 'Enum' used before its declaration.
+!!! related TS2728 decoratorUsedBeforeDeclaration.ts:35:6: 'Enum' is declared here.
+                   ~~
+!!! error TS2729: Property 'No' is used before its initialization.
+!!! related TS2728 decoratorUsedBeforeDeclaration.ts:36:3: 'No' is declared here.
+      @deco(Enum.No)
+            ~~~~
+!!! error TS2450: Enum 'Enum' used before its declaration.
+!!! related TS2728 decoratorUsedBeforeDeclaration.ts:35:6: 'Enum' is declared here.
+                 ~~
+!!! error TS2729: Property 'No' is used before its initialization.
+!!! related TS2728 decoratorUsedBeforeDeclaration.ts:36:3: 'No' is declared here.
+      greeting: string;
+
+      constructor(message: string) {
+        this.greeting = message;
+      }
+
+      @lambda(Enum.No)
+       ~~~~~~
+!!! error TS2448: Block-scoped variable 'lambda' used before its declaration.
+!!! related TS2728 decoratorUsedBeforeDeclaration.ts:40:7: 'lambda' is declared here.
+              ~~~~
+!!! error TS2450: Enum 'Enum' used before its declaration.
+!!! related TS2728 decoratorUsedBeforeDeclaration.ts:35:6: 'Enum' is declared here.
+      @deco(Enum.No)
+            ~~~~
+!!! error TS2450: Enum 'Enum' used before its declaration.
+!!! related TS2728 decoratorUsedBeforeDeclaration.ts:35:6: 'Enum' is declared here.
+      greet() {
+        return "Hello, " + this.greeting;
+      }
+
+      @lambda
+       ~~~~~~
+!!! error TS2448: Block-scoped variable 'lambda' used before its declaration.
+!!! related TS2728 decoratorUsedBeforeDeclaration.ts:40:7: 'lambda' is declared here.
+      @deco
+      greet1() {
+        return "Hello, " + this.greeting;
+      }
+
+      greet2(@lambda(Enum.No) @deco(Enum.No) param) {
+              ~~~~~~
+!!! error TS2448: Block-scoped variable 'lambda' used before its declaration.
+!!! related TS2728 decoratorUsedBeforeDeclaration.ts:40:7: 'lambda' is declared here.
+                     ~~~~
+!!! error TS2450: Enum 'Enum' used before its declaration.
+!!! related TS2728 decoratorUsedBeforeDeclaration.ts:35:6: 'Enum' is declared here.
+                                    ~~~~
+!!! error TS2450: Enum 'Enum' used before its declaration.
+!!! related TS2728 decoratorUsedBeforeDeclaration.ts:35:6: 'Enum' is declared here.
+        return "Hello, " + this.greeting;
+      }
+
+      greet3(@lambda @deco param) {
+              ~~~~~~
+!!! error TS2448: Block-scoped variable 'lambda' used before its declaration.
+!!! related TS2728 decoratorUsedBeforeDeclaration.ts:40:7: 'lambda' is declared here.
+        return "Hello, " + this.greeting;
+      }
+    }
+
+    function deco(...args: any[]): any {}
+
+    enum Enum {
+      No = 0,
+      Yes = 1,
+    }
+
+    const lambda = (...args: any[]): any => {};
+
+    @lambda(Enum.No)
+    @deco(Enum.No)
+    class Greeter1 {
+      @lambda(Enum.No)
+      @deco(Enum.No)
+      greeting: string;
+
+      constructor(message: string) {
+        this.greeting = message;
+      }
+
+      @lambda(Enum.No)
+      @deco(Enum.No)
+      greet() {
+        return "Hello, " + this.greeting;
+      }
+
+      @lambda
+      @deco
+      greet1() {
+        return "Hello, " + this.greeting;
+      }
+
+      greet2(@lambda(Enum.No) @deco(Enum.No) param) {
+        return "Hello, " + this.greeting;
+      }
+
+      greet3(@lambda @deco param) {
+        return "Hello, " + this.greeting;
+      }
+    }
+