From 15babc4f1db8e5084c4694c441cb36079aa77d50 Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Sun, 27 Jun 2021 15:29:02 -0700
Subject: [PATCH 01/17] esm: refine ERR_REQUIRE_ESM errors

---
 lib/internal/errors.js                        | 87 +++++++++++++++----
 lib/internal/modules/cjs/helpers.js           | 32 +++++++
 lib/internal/modules/cjs/loader.js            | 63 ++++++++++----
 src/node_errors.cc                            |  6 ++
 test/es-module/test-cjs-esm-warn.js           | 77 ++++++++++------
 test/es-module/test-esm-type-flag-errors.js   |  4 +-
 test/fixtures/es-modules/cjs-esm-esm.js       |  1 +
 .../es-modules/package-type-module/esm.js     |  1 +
 8 files changed, 206 insertions(+), 65 deletions(-)
 create mode 100644 test/fixtures/es-modules/cjs-esm-esm.js
 create mode 100644 test/fixtures/es-modules/package-type-module/esm.js

diff --git a/lib/internal/errors.js b/lib/internal/errors.js
index 30a2a8c0399ba8..78b8eafca5ee92 100644
--- a/lib/internal/errors.js
+++ b/lib/internal/errors.js
@@ -14,6 +14,7 @@ const {
   AggregateError,
   ArrayFrom,
   ArrayIsArray,
+  ArrayPrototypeFilter,
   ArrayPrototypeIncludes,
   ArrayPrototypeIndexOf,
   ArrayPrototypeJoin,
@@ -337,7 +338,7 @@ function makeSystemErrorWithCode(key) {
   };
 }
 
-function makeNodeErrorWithCode(Base, key) {
+function makeNodeErrorWithCode(Base, key, deferStack) {
   return function NodeError(...args) {
     const limit = Error.stackTraceLimit;
     if (isErrorStackTraceLimitWritable()) Error.stackTraceLimit = 0;
@@ -389,18 +390,19 @@ function hideStackFrames(fn) {
 // Utility function for registering the error codes. Only used here. Exported
 // *only* to allow for testing.
 function E(sym, val, def, ...otherClasses) {
+  const deferStack = overrideStackTraceByCode.has(sym);
   // Special case for SystemError that formats the error message differently
   // The SystemErrors only have SystemError as their base classes.
   messages.set(sym, val);
   if (def === SystemError) {
     def = makeSystemErrorWithCode(sym);
   } else {
-    def = makeNodeErrorWithCode(def, sym);
+    def = makeNodeErrorWithCode(def, sym, deferStack);
   }
 
   if (otherClasses.length !== 0) {
     otherClasses.forEach((clazz) => {
-      def[clazz.name] = makeNodeErrorWithCode(clazz, sym);
+      def[clazz.name] = makeNodeErrorWithCode(clazz, sym, deferStack);
     });
   }
   codes[sym] = def;
@@ -788,6 +790,40 @@ const fatalExceptionStackEnhancers = {
   }
 };
 
+// Ensures the printed error line is from user code.
+let _kArrowMessagePrivateSymbol, _setHiddenValue;
+function setArrowMessage(err, arrowMessage) {
+  if (!_kArrowMessagePrivateSymbol) {
+    ({
+      arrow_message_private_symbol: _kArrowMessagePrivateSymbol,
+      setHiddenValue: _setHiddenValue,
+    } = internalBinding('util'));
+  }
+  _setHiddenValue(err, _kArrowMessagePrivateSymbol, arrowMessage);
+}
+
+// Hide stack lines before the first user code line.
+function hideLeadingInternalFrames(error, stackFrames) {
+  let frames = stackFrames;
+  if (typeof stackFrames === 'object') {
+    let beforeUserCode = true;
+    frames = ArrayPrototypeFilter(
+      stackFrames,
+      (frm) => {
+        if (!beforeUserCode)
+          return true;
+        const isInternal = StringPrototypeStartsWith(frm.getFileName(),
+                                                     'node:internal');
+        if (!isInternal)
+          beforeUserCode = false;
+        return !isInternal;
+      },
+    );
+  }
+  ArrayPrototypeUnshift(frames, error);
+  return ArrayPrototypeJoin(frames, '\n    at ');
+}
+
 // Node uses an AbortError that isn't exactly the same as the DOMException
 // to make usage of the error in userland and readable-stream easier.
 // It is a regular error with `.code` and `.name`.
@@ -808,6 +844,7 @@ module.exports = {
   hideStackFrames,
   isErrorStackTraceLimitWritable,
   isStackOverflowError,
+  setArrowMessage,
   connResetException,
   uvErrmapGet,
   uvException,
@@ -842,6 +879,12 @@ module.exports = {
 // Note: Please try to keep these in alphabetical order
 //
 // Note: Node.js specific errors must begin with the prefix ERR_
+
+// Custom error stack overrides.
+const overrideStackTraceByCode = new SafeMap([
+  ['ERR_REQUIRE_ESM', hideLeadingInternalFrames],
+]);
+
 E('ERR_AMBIGUOUS_ARGUMENT', 'The "%s" argument is ambiguous. %s', TypeError);
 E('ERR_ARG_NOT_ITERABLE', '%s must be iterable', TypeError);
 E('ERR_ASSERTION', '%s', Error);
@@ -1406,23 +1449,31 @@ E('ERR_PERFORMANCE_INVALID_TIMESTAMP',
   '%d is not a valid timestamp', TypeError);
 E('ERR_PERFORMANCE_MEASURE_INVALID_OPTIONS', '%s', TypeError);
 E('ERR_REQUIRE_ESM',
-  (filename, parentPath = null, packageJsonPath = null) => {
-    let msg = `Must use import to load ES Module: ${filename}`;
-    if (parentPath && packageJsonPath) {
-      const path = require('path');
-      const basename = path.basename(filename) === path.basename(parentPath) ?
-        filename : path.basename(filename);
-      msg +=
-        '\nrequire() of ES modules is not supported.\nrequire() of ' +
-        `${filename} from ${parentPath} ` +
-        'is an ES module file as it is a .js file whose nearest parent ' +
-        'package.json contains "type": "module" which defines all .js ' +
-        'files in that package scope as ES modules.\nInstead rename ' +
-        `${basename} to end in .cjs, change the requiring code to use ` +
-        'import(), or remove "type": "module" from ' +
-        `${packageJsonPath}.\n`;
+  function(filename, hasEsmSyntax, parentPath = null, packageJsonPath = null) {
+    let msg = `require() of ES Module ${filename}${parentPath ? ` from ${
+      parentPath}` : ''} not supported.`;
+    if (!packageJsonPath) {
+      if (filename.endsWith('.mjs'))
+        msg += `\nInstead change the require of ${filename} to a dynamic ` +
+            'import() which is available in all CommonJS modules.';
+      return msg;
+    }
+    const path = require('path');
+    const basename = path.basename(filename) === path.basename(parentPath) ?
+      filename : path.basename(filename);
+    if (hasEsmSyntax) {
+      msg += `\nInstead change the require of ${basename} in ${parentPath} to` +
+        ' a dynamic import() which is available in all CommonJS modules.';
       return msg;
     }
+    msg += `\n${basename} is treated as an ES module file as it is a .js ` +
+      'file whose nearest parent package.json contains "type": "module" ' +
+      'which declares all .js files in that package scope as ES modules.' +
+      `\nInstead rename ${basename} to end in .cjs, change the requiring ` +
+      'code to use dynamic import() which is available in all CommonJS' +
+      `modules, or remove "type": "module" from ${packageJsonPath} to ` +
+      'treat all .js files as CommonJS (using .mjs for all ES modules ' +
+      'instead).\n';
     return msg;
   }, Error);
 E('ERR_SCRIPT_EXECUTION_INTERRUPTED',
diff --git a/lib/internal/modules/cjs/helpers.js b/lib/internal/modules/cjs/helpers.js
index 94602b5309efff..c3ea5e884c51b4 100644
--- a/lib/internal/modules/cjs/helpers.js
+++ b/lib/internal/modules/cjs/helpers.js
@@ -29,6 +29,14 @@ let debug = require('internal/util/debuglog').debuglog('module', (fn) => {
   debug = fn;
 });
 
+const acorn = require('internal/deps/acorn/acorn/dist/acorn');
+const privateMethods =
+  require('internal/deps/acorn-plugins/acorn-private-methods/index');
+const classFields =
+  require('internal/deps/acorn-plugins/acorn-class-fields/index');
+const staticClassFeatures =
+  require('internal/deps/acorn-plugins/acorn-static-class-features/index');
+
 // TODO: Use this set when resolving pkg#exports conditions in loader.js.
 const cjsConditions = new SafeSet(['require', 'node', ...userConditions]);
 
@@ -184,9 +192,33 @@ function normalizeReferrerURL(referrer) {
   return new URL(referrer).href;
 }
 
+// For error messages only - used to check if ESM syntax is in use.
+function hasEsmSyntax(code) {
+  const parser = acorn.Parser.extend(
+    privateMethods,
+    classFields,
+    staticClassFeatures
+  );
+  let root;
+  try {
+    root = parser.parse(code, { sourceType: 'module', ecmaVersion: 'latest' });
+  } catch {
+    return false;
+  }
+
+  for (const stmt of root.body) {
+    if (stmt.type === 'ExportNamedDeclaration' ||
+        stmt.type === 'ImportDeclaration' ||
+        stmt.type === 'ExportAllDeclaration')
+      return true;
+  }
+  return false;
+}
+
 module.exports = {
   addBuiltinLibsToObject,
   cjsConditions,
+  hasEsmSyntax,
   loadNativeModule,
   makeRequireFunction,
   normalizeReferrerURL,
diff --git a/lib/internal/modules/cjs/loader.js b/lib/internal/modules/cjs/loader.js
index d969a6449cf545..41cae1d83282cc 100644
--- a/lib/internal/modules/cjs/loader.js
+++ b/lib/internal/modules/cjs/loader.js
@@ -58,6 +58,7 @@ const {
   StringPrototypeLastIndexOf,
   StringPrototypeIndexOf,
   StringPrototypeMatch,
+  StringPrototypeRepeat,
   StringPrototypeSlice,
   StringPrototypeSplit,
   StringPrototypeStartsWith,
@@ -88,11 +89,12 @@ const { internalModuleStat } = internalBinding('fs');
 const packageJsonReader = require('internal/modules/package_json_reader');
 const { safeGetenv } = internalBinding('credentials');
 const {
+  cjsConditions,
+  hasEsmSyntax,
+  loadNativeModule,
   makeRequireFunction,
   normalizeReferrerURL,
   stripBOM,
-  cjsConditions,
-  loadNativeModule
 } = require('internal/modules/cjs/helpers');
 const { getOptionValue } = require('internal/options');
 const preserveSymlinks = getOptionValue('--preserve-symlinks');
@@ -107,11 +109,14 @@ const policy = getOptionValue('--experimental-policy') ?
 let hasLoadedAnyUserCJSModule = false;
 
 const {
-  ERR_INVALID_ARG_VALUE,
-  ERR_INVALID_MODULE_SPECIFIER,
-  ERR_REQUIRE_ESM,
-  ERR_UNKNOWN_BUILTIN_MODULE,
-} = require('internal/errors').codes;
+  codes: {
+    ERR_INVALID_ARG_VALUE,
+    ERR_INVALID_MODULE_SPECIFIER,
+    ERR_REQUIRE_ESM,
+    ERR_UNKNOWN_BUILTIN_MODULE,
+  },
+  setArrowMessage,
+} = require('internal/errors');
 const { validateString } = require('internal/validators');
 const pendingDeprecation = getOptionValue('--pending-deprecation');
 
@@ -970,7 +975,7 @@ Module.prototype.load = function(filename) {
   const extension = findLongestRegisteredExtension(filename);
   // allow .mjs to be overridden
   if (StringPrototypeEndsWith(filename, '.mjs') && !Module._extensions['.mjs'])
-    throw new ERR_REQUIRE_ESM(filename);
+    throw new ERR_REQUIRE_ESM(filename, true);
 
   Module._extensions[extension](this, filename);
   this.loaded = true;
@@ -1102,16 +1107,6 @@ Module.prototype._compile = function(content, filename) {
 
 // Native extension for .js
 Module._extensions['.js'] = function(module, filename) {
-  if (StringPrototypeEndsWith(filename, '.js')) {
-    const pkg = readPackageScope(filename);
-    // Function require shouldn't be used in ES modules.
-    if (pkg?.data?.type === 'module') {
-      const parent = moduleParentCache.get(module);
-      const parentPath = parent?.filename;
-      const packageJsonPath = path.resolve(pkg.path, 'package.json');
-      throw new ERR_REQUIRE_ESM(filename, parentPath, packageJsonPath);
-    }
-  }
   // If already analyzed the source, then it will be cached.
   const cached = cjsParseCache.get(module);
   let content;
@@ -1121,6 +1116,38 @@ Module._extensions['.js'] = function(module, filename) {
   } else {
     content = fs.readFileSync(filename, 'utf8');
   }
+  if (StringPrototypeEndsWith(filename, '.js')) {
+    const pkg = readPackageScope(filename);
+    // Function require shouldn't be used in ES modules.
+    if (pkg?.data?.type === 'module') {
+      const parent = moduleParentCache.get(module);
+      const parentPath = parent?.filename;
+      const packageJsonPath = path.resolve(pkg.path, 'package.json');
+      const usesEsm = hasEsmSyntax(content);
+      const err = new ERR_REQUIRE_ESM(filename, usesEsm, parentPath,
+                                      packageJsonPath);
+      // Attempt to reconstruct the parent require frame.
+      if (Module._cache[parentPath]) {
+        let parentSource;
+        try {
+          parentSource = fs.readFileSync(parentPath, 'utf8');
+        } catch {}
+        if (parentSource) {
+          const errLine = StringPrototypeSplit(StringPrototypeSlice(
+            err.stack, StringPrototypeIndexOf(err.stack, '    at ')), '\n')[0];
+          const { 1: line, 2: col } =
+              StringPrototypeMatch(errLine, /(\d+):(\d+)\)/) || [];
+          if (line && col) {
+            const srcLine = StringPrototypeSplit(parentSource, '\n')[line - 1];
+            const frame = `${parentPath}:${line}\n${srcLine}\n${
+              StringPrototypeRepeat(' ', col - 1)}^\n`;
+            setArrowMessage(err, frame);
+          }
+        }
+      }
+      throw err;
+    }
+  }
   module._compile(content, filename);
 };
 
diff --git a/src/node_errors.cc b/src/node_errors.cc
index a22493a140dfd2..d424344708c7fc 100644
--- a/src/node_errors.cc
+++ b/src/node_errors.cc
@@ -215,6 +215,12 @@ void AppendExceptionLine(Environment* env,
   Local<Object> err_obj;
   if (!er.IsEmpty() && er->IsObject()) {
     err_obj = er.As<Object>();
+    // If arrow_message is already set, skip.
+    auto maybe_value = err_obj->GetPrivate(env->context(),
+                                          env->arrow_message_private_symbol());
+    Local<Value> lvalue;
+    if (maybe_value.ToLocal(&lvalue) && lvalue->IsString())
+      return;
   }
 
   bool added_exception_line = false;
diff --git a/test/es-module/test-cjs-esm-warn.js b/test/es-module/test-cjs-esm-warn.js
index ddeda72fc84b41..70d0524f421339 100644
--- a/test/es-module/test-cjs-esm-warn.js
+++ b/test/es-module/test-cjs-esm-warn.js
@@ -6,36 +6,59 @@ const { spawn } = require('child_process');
 const assert = require('assert');
 const path = require('path');
 
-const requiring = path.resolve(fixtures.path('/es-modules/cjs-esm.js'));
-const required = path.resolve(
-  fixtures.path('/es-modules/package-type-module/cjs.js')
-);
+const requiringCjsAsEsm = path.resolve(fixtures.path('/es-modules/cjs-esm.js'));
+const requiringEsm = path.resolve(fixtures.path('/es-modules/cjs-esm-esm.js'));
 const pjson = path.resolve(
   fixtures.path('/es-modules/package-type-module/package.json')
 );
 
-const basename = 'cjs.js';
+{
+  const required = path.resolve(
+    fixtures.path('/es-modules/package-type-module/cjs.js')
+  );
+  const basename = 'cjs.js';
+  const child = spawn(process.execPath, [requiringCjsAsEsm]);
+  let stderr = '';
+  child.stderr.setEncoding('utf8');
+  child.stderr.on('data', (data) => {
+    stderr += data;
+  });
+  child.on('close', common.mustCall((code, signal) => {
+    assert.strictEqual(code, 1);
+    assert.strictEqual(signal, null);
+
+    assert.ok(stderr.replace(/\r/g, '').includes(
+      `Error [ERR_REQUIRE_ESM]: require() of ES Module ${required} from ${
+        requiringCjsAsEsm} not supported.\n`));
+    assert.ok(stderr.includes(
+      `Instead rename ${basename} to end in .cjs, change the requiring ` +
+      'code to use dynamic import() which is available in all CommonJS' +
+      `modules, or remove "type": "module" from ${pjson} to ` +
+      'treat all .js files as CommonJS (using .mjs for all ES modules ' +
+      'instead).\n'));
+  }));
+}
 
-const child = spawn(process.execPath, [requiring]);
-let stderr = '';
-child.stderr.setEncoding('utf8');
-child.stderr.on('data', (data) => {
-  stderr += data;
-});
-child.on('close', common.mustCall((code, signal) => {
-  assert.strictEqual(code, 1);
-  assert.strictEqual(signal, null);
+{
+  const required = path.resolve(
+    fixtures.path('/es-modules/package-type-module/esm.js')
+  );
+  const basename = 'esm.js';
+  const child = spawn(process.execPath, [requiringEsm]);
+  let stderr = '';
+  child.stderr.setEncoding('utf8');
+  child.stderr.on('data', (data) => {
+    stderr += data;
+  });
+  child.on('close', common.mustCall((code, signal) => {
+    assert.strictEqual(code, 1);
+    assert.strictEqual(signal, null);
 
-  assert.ok(stderr.replace(/\r/g, '').includes(
-    `Error [ERR_REQUIRE_ESM]: Must use import to load ES Module: ${required}` +
-    '\nrequire() of ES modules is not supported.\nrequire() of ' +
-    `${required} from ${requiring} ` +
-    'is an ES module file as it is a .js file whose nearest parent ' +
-    'package.json contains "type": "module" which defines all .js ' +
-    'files in that package scope as ES modules.\nInstead rename ' +
-    `${basename} to end in .cjs, change the requiring code to use ` +
-    'import(), or remove "type": "module" from ' +
-    `${pjson}.\n`));
-  assert.ok(stderr.includes(
-    'Error [ERR_REQUIRE_ESM]: Must use import to load ES Module'));
-}));
+    assert.ok(stderr.replace(/\r/g, '').includes(
+      `Error [ERR_REQUIRE_ESM]: require() of ES Module ${required} from ${
+        requiringEsm} not supported.\n`));
+    assert.ok(stderr.includes(
+      `Instead change the require of ${basename} in ${requiringEsm} to` +
+      ' a dynamic import() which is available in all CommonJS modules.\n'));
+  }));
+}
diff --git a/test/es-module/test-esm-type-flag-errors.js b/test/es-module/test-esm-type-flag-errors.js
index e0dedc16cabf8c..d9d264cc25aa25 100644
--- a/test/es-module/test-esm-type-flag-errors.js
+++ b/test/es-module/test-esm-type-flag-errors.js
@@ -29,8 +29,8 @@ try {
 } catch (e) {
   assert.strictEqual(e.name, 'Error');
   assert.strictEqual(e.code, 'ERR_REQUIRE_ESM');
-  assert(e.toString().match(/Must use import to load ES Module/g));
-  assert(e.message.match(/Must use import to load ES Module/g));
+  assert(e.toString().match(/require\(\) of ES Module/g));
+  assert(e.message.match(/require\(\) of ES Module/g));
 }
 
 function expect(opt = '', inputFile, want, wantsError = false) {
diff --git a/test/fixtures/es-modules/cjs-esm-esm.js b/test/fixtures/es-modules/cjs-esm-esm.js
new file mode 100644
index 00000000000000..0a0cdfb1e56327
--- /dev/null
+++ b/test/fixtures/es-modules/cjs-esm-esm.js
@@ -0,0 +1 @@
+require('./package-type-module/esm.js');
diff --git a/test/fixtures/es-modules/package-type-module/esm.js b/test/fixtures/es-modules/package-type-module/esm.js
new file mode 100644
index 00000000000000..1413bf5968ad73
--- /dev/null
+++ b/test/fixtures/es-modules/package-type-module/esm.js
@@ -0,0 +1 @@
+export var p = 5;

From 8b6d578e781408f195e0673ddd98ff30a8d92033 Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Sun, 27 Jun 2021 15:53:11 -0700
Subject: [PATCH 02/17] fixup: space

---
 lib/internal/errors.js              | 2 +-
 test/es-module/test-cjs-esm-warn.js | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/internal/errors.js b/lib/internal/errors.js
index 78b8eafca5ee92..af6ee960e856bb 100644
--- a/lib/internal/errors.js
+++ b/lib/internal/errors.js
@@ -1470,7 +1470,7 @@ E('ERR_REQUIRE_ESM',
       'file whose nearest parent package.json contains "type": "module" ' +
       'which declares all .js files in that package scope as ES modules.' +
       `\nInstead rename ${basename} to end in .cjs, change the requiring ` +
-      'code to use dynamic import() which is available in all CommonJS' +
+      'code to use dynamic import() which is available in all CommonJS ' +
       `modules, or remove "type": "module" from ${packageJsonPath} to ` +
       'treat all .js files as CommonJS (using .mjs for all ES modules ' +
       'instead).\n';
diff --git a/test/es-module/test-cjs-esm-warn.js b/test/es-module/test-cjs-esm-warn.js
index 70d0524f421339..cdda3ed9064d6c 100644
--- a/test/es-module/test-cjs-esm-warn.js
+++ b/test/es-module/test-cjs-esm-warn.js
@@ -32,7 +32,7 @@ const pjson = path.resolve(
         requiringCjsAsEsm} not supported.\n`));
     assert.ok(stderr.includes(
       `Instead rename ${basename} to end in .cjs, change the requiring ` +
-      'code to use dynamic import() which is available in all CommonJS' +
+      'code to use dynamic import() which is available in all CommonJS ' +
       `modules, or remove "type": "module" from ${pjson} to ` +
       'treat all .js files as CommonJS (using .mjs for all ES modules ' +
       'instead).\n'));

From 0d129ba05c070345b6ded60fb4f3c906d25d77b3 Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Sun, 27 Jun 2021 15:55:48 -0700
Subject: [PATCH 03/17] fixup: arrow fn

---
 lib/internal/errors.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/internal/errors.js b/lib/internal/errors.js
index af6ee960e856bb..86dc365cd745d5 100644
--- a/lib/internal/errors.js
+++ b/lib/internal/errors.js
@@ -1449,7 +1449,7 @@ E('ERR_PERFORMANCE_INVALID_TIMESTAMP',
   '%d is not a valid timestamp', TypeError);
 E('ERR_PERFORMANCE_MEASURE_INVALID_OPTIONS', '%s', TypeError);
 E('ERR_REQUIRE_ESM',
-  function(filename, hasEsmSyntax, parentPath = null, packageJsonPath = null) {
+  (filename, hasEsmSyntax, parentPath = null, packageJsonPath = null) => {
     let msg = `require() of ES Module ${filename}${parentPath ? ` from ${
       parentPath}` : ''} not supported.`;
     if (!packageJsonPath) {

From 7765a14aebd87335aa08a5626f6307ce235316d4 Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Sun, 27 Jun 2021 16:40:19 -0700
Subject: [PATCH 04/17] fixup: Apply suggestions from code review

Co-authored-by: Antoine du Hamel <duhamelantoine1995@gmail.com>
---
 lib/internal/errors.js | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/lib/internal/errors.js b/lib/internal/errors.js
index 86dc365cd745d5..4f541154283bcc 100644
--- a/lib/internal/errors.js
+++ b/lib/internal/errors.js
@@ -115,6 +115,13 @@ const prepareStackTrace = (globalThis, error, trace) => {
     maybeOverridePrepareStackTrace(globalThis, error, trace);
   if (globalOverride !== kNoOverride) return globalOverride;
 
+  // try to avoid unnecessary getter calls
+  const code = error.code;
+  if (code && overrideStackTraceByCode.has(code)) {
+    const f = overrideStackTraceByCode.get(code);
+    return f(error, trace);
+  }
+
   // Normal error formatting:
   //
   // Error: Message
@@ -881,9 +888,8 @@ module.exports = {
 // Note: Node.js specific errors must begin with the prefix ERR_
 
 // Custom error stack overrides.
-const overrideStackTraceByCode = new SafeMap([
-  ['ERR_REQUIRE_ESM', hideLeadingInternalFrames],
-]);
+const overrideStackTraceByCode = new SafeMap()
+  .set('ERR_REQUIRE_ESM', hideLeadingInternalFrames);
 
 E('ERR_AMBIGUOUS_ARGUMENT', 'The "%s" argument is ambiguous. %s', TypeError);
 E('ERR_ARG_NOT_ITERABLE', '%s must be iterable', TypeError);

From 187c7b948bab687923a8e2a78ea9eaf5df9d405f Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Mon, 28 Jun 2021 06:21:06 -0700
Subject: [PATCH 05/17] fixup: pr feedback

---
 lib/internal/errors.js              | 28 ++++++++++++++--------------
 lib/internal/modules/cjs/helpers.js | 12 +++++-------
 src/node_errors.cc                  |  2 +-
 3 files changed, 20 insertions(+), 22 deletions(-)

diff --git a/lib/internal/errors.js b/lib/internal/errors.js
index 4f541154283bcc..0cd32da53860d1 100644
--- a/lib/internal/errors.js
+++ b/lib/internal/errors.js
@@ -14,7 +14,7 @@ const {
   AggregateError,
   ArrayFrom,
   ArrayIsArray,
-  ArrayPrototypeFilter,
+  ArrayPrototypeFindIndex,
   ArrayPrototypeIncludes,
   ArrayPrototypeIndexOf,
   ArrayPrototypeJoin,
@@ -122,6 +122,12 @@ const prepareStackTrace = (globalThis, error, trace) => {
     return f(error, trace);
   }
 
+  const { code } = error;
+  if (code && overrideStackTraceByCode.has(code)) {
+    const f = overrideStackTraceByCode.get(code);
+    return f(error, trace);
+  }
+
   // Normal error formatting:
   //
   // Error: Message
@@ -813,19 +819,13 @@ function setArrowMessage(err, arrowMessage) {
 function hideLeadingInternalFrames(error, stackFrames) {
   let frames = stackFrames;
   if (typeof stackFrames === 'object') {
-    let beforeUserCode = true;
-    frames = ArrayPrototypeFilter(
+    frames = ArrayPrototypeSlice(
       stackFrames,
-      (frm) => {
-        if (!beforeUserCode)
-          return true;
-        const isInternal = StringPrototypeStartsWith(frm.getFileName(),
-                                                     'node:internal');
-        if (!isInternal)
-          beforeUserCode = false;
-        return !isInternal;
-      },
-    );
+      ArrayPrototypeFindIndex(
+        stackFrames,
+        (frm) => !StringPrototypeStartsWith(frm.getFileName(),
+                                            'node:internal')
+    ));
   }
   ArrayPrototypeUnshift(frames, error);
   return ArrayPrototypeJoin(frames, '\n    at ');
@@ -1459,7 +1459,7 @@ E('ERR_REQUIRE_ESM',
     let msg = `require() of ES Module ${filename}${parentPath ? ` from ${
       parentPath}` : ''} not supported.`;
     if (!packageJsonPath) {
-      if (filename.endsWith('.mjs'))
+      if (StringPrototypeEndsWith(filename, '.mjs'))
         msg += `\nInstead change the require of ${filename} to a dynamic ` +
             'import() which is available in all CommonJS modules.';
       return msg;
diff --git a/lib/internal/modules/cjs/helpers.js b/lib/internal/modules/cjs/helpers.js
index c3ea5e884c51b4..6d229a0422ea12 100644
--- a/lib/internal/modules/cjs/helpers.js
+++ b/lib/internal/modules/cjs/helpers.js
@@ -3,6 +3,7 @@
 const {
   ArrayPrototypeForEach,
   ArrayPrototypeJoin,
+  ArrayPrototypeSome,
   ObjectDefineProperty,
   ObjectPrototypeHasOwnProperty,
   SafeMap,
@@ -206,13 +207,10 @@ function hasEsmSyntax(code) {
     return false;
   }
 
-  for (const stmt of root.body) {
-    if (stmt.type === 'ExportNamedDeclaration' ||
-        stmt.type === 'ImportDeclaration' ||
-        stmt.type === 'ExportAllDeclaration')
-      return true;
-  }
-  return false;
+  return ArrayPrototypeSome(root.body, (stmt) =>
+    stmt.type === 'ExportNamedDeclaration' ||
+    stmt.type === 'ImportDeclaration' ||
+    stmt.type === 'ExportAllDeclaration');
 }
 
 module.exports = {
diff --git a/src/node_errors.cc b/src/node_errors.cc
index d424344708c7fc..b64c2d831eae21 100644
--- a/src/node_errors.cc
+++ b/src/node_errors.cc
@@ -219,7 +219,7 @@ void AppendExceptionLine(Environment* env,
     auto maybe_value = err_obj->GetPrivate(env->context(),
                                           env->arrow_message_private_symbol());
     Local<Value> lvalue;
-    if (maybe_value.ToLocal(&lvalue) && lvalue->IsString())
+    if (!maybe_value.ToLocal(&lvalue) || lvalue->IsString())
       return;
   }
 

From 8fbf23bfe27a52ada56da44c4cbfb8758f0d0fd7 Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Mon, 28 Jun 2021 06:35:53 -0700
Subject: [PATCH 06/17] fixup: errors linting

---
 lib/internal/errors.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/internal/errors.js b/lib/internal/errors.js
index 0cd32da53860d1..7d64d92e511ed8 100644
--- a/lib/internal/errors.js
+++ b/lib/internal/errors.js
@@ -825,7 +825,8 @@ function hideLeadingInternalFrames(error, stackFrames) {
         stackFrames,
         (frm) => !StringPrototypeStartsWith(frm.getFileName(),
                                             'node:internal')
-    ));
+      )
+    );
   }
   ArrayPrototypeUnshift(frames, error);
   return ArrayPrototypeJoin(frames, '\n    at ');

From fdd9b31f3eaf4125fdaca7edba3944ce76428ef2 Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Thu, 8 Jul 2021 10:26:13 -0700
Subject: [PATCH 07/17] fixup: simplify internal stack frame hiding

---
 lib/internal/errors.js              | 51 ++++++++++-------------------
 lib/internal/modules/cjs/helpers.js | 13 +-------
 2 files changed, 18 insertions(+), 46 deletions(-)

diff --git a/lib/internal/errors.js b/lib/internal/errors.js
index 7d64d92e511ed8..3a46157b2e3503 100644
--- a/lib/internal/errors.js
+++ b/lib/internal/errors.js
@@ -14,7 +14,7 @@ const {
   AggregateError,
   ArrayFrom,
   ArrayIsArray,
-  ArrayPrototypeFindIndex,
+  ArrayPrototypeFilter,
   ArrayPrototypeIncludes,
   ArrayPrototypeIndexOf,
   ArrayPrototypeJoin,
@@ -115,19 +115,6 @@ const prepareStackTrace = (globalThis, error, trace) => {
     maybeOverridePrepareStackTrace(globalThis, error, trace);
   if (globalOverride !== kNoOverride) return globalOverride;
 
-  // try to avoid unnecessary getter calls
-  const code = error.code;
-  if (code && overrideStackTraceByCode.has(code)) {
-    const f = overrideStackTraceByCode.get(code);
-    return f(error, trace);
-  }
-
-  const { code } = error;
-  if (code && overrideStackTraceByCode.has(code)) {
-    const f = overrideStackTraceByCode.get(code);
-    return f(error, trace);
-  }
-
   // Normal error formatting:
   //
   // Error: Message
@@ -351,7 +338,7 @@ function makeSystemErrorWithCode(key) {
   };
 }
 
-function makeNodeErrorWithCode(Base, key, deferStack) {
+function makeNodeErrorWithCode(Base, key) {
   return function NodeError(...args) {
     const limit = Error.stackTraceLimit;
     if (isErrorStackTraceLimitWritable()) Error.stackTraceLimit = 0;
@@ -403,19 +390,18 @@ function hideStackFrames(fn) {
 // Utility function for registering the error codes. Only used here. Exported
 // *only* to allow for testing.
 function E(sym, val, def, ...otherClasses) {
-  const deferStack = overrideStackTraceByCode.has(sym);
   // Special case for SystemError that formats the error message differently
   // The SystemErrors only have SystemError as their base classes.
   messages.set(sym, val);
   if (def === SystemError) {
     def = makeSystemErrorWithCode(sym);
   } else {
-    def = makeNodeErrorWithCode(def, sym, deferStack);
+    def = makeNodeErrorWithCode(def, sym);
   }
 
   if (otherClasses.length !== 0) {
     otherClasses.forEach((clazz) => {
-      def[clazz.name] = makeNodeErrorWithCode(clazz, sym, deferStack);
+      def[clazz.name] = makeNodeErrorWithCode(clazz, sym);
     });
   }
   codes[sym] = def;
@@ -816,20 +802,19 @@ function setArrowMessage(err, arrowMessage) {
 }
 
 // Hide stack lines before the first user code line.
-function hideLeadingInternalFrames(error, stackFrames) {
-  let frames = stackFrames;
-  if (typeof stackFrames === 'object') {
-    frames = ArrayPrototypeSlice(
-      stackFrames,
-      ArrayPrototypeFindIndex(
+function hideInternalStackFrames(error) {
+  overrideStackTrace.set(error, (error, stackFrames) => {
+    let frames = stackFrames;
+    if (typeof stackFrames === 'object') {
+      frames = ArrayPrototypeFilter(
         stackFrames,
         (frm) => !StringPrototypeStartsWith(frm.getFileName(),
                                             'node:internal')
-      )
-    );
-  }
-  ArrayPrototypeUnshift(frames, error);
-  return ArrayPrototypeJoin(frames, '\n    at ');
+      );
+    }
+    ArrayPrototypeUnshift(frames, error);
+    return ArrayPrototypeJoin(frames, '\n    at ');
+  });
 }
 
 // Node uses an AbortError that isn't exactly the same as the DOMException
@@ -850,6 +835,7 @@ module.exports = {
   exceptionWithHostPort,
   getMessage,
   hideStackFrames,
+  hideInternalStackFrames,
   isErrorStackTraceLimitWritable,
   isStackOverflowError,
   setArrowMessage,
@@ -888,10 +874,6 @@ module.exports = {
 //
 // Note: Node.js specific errors must begin with the prefix ERR_
 
-// Custom error stack overrides.
-const overrideStackTraceByCode = new SafeMap()
-  .set('ERR_REQUIRE_ESM', hideLeadingInternalFrames);
-
 E('ERR_AMBIGUOUS_ARGUMENT', 'The "%s" argument is ambiguous. %s', TypeError);
 E('ERR_ARG_NOT_ITERABLE', '%s must be iterable', TypeError);
 E('ERR_ASSERTION', '%s', Error);
@@ -1456,7 +1438,8 @@ E('ERR_PERFORMANCE_INVALID_TIMESTAMP',
   '%d is not a valid timestamp', TypeError);
 E('ERR_PERFORMANCE_MEASURE_INVALID_OPTIONS', '%s', TypeError);
 E('ERR_REQUIRE_ESM',
-  (filename, hasEsmSyntax, parentPath = null, packageJsonPath = null) => {
+  function(filename, hasEsmSyntax, parentPath = null, packageJsonPath = null) {
+    hideInternalStackFrames(this);
     let msg = `require() of ES Module ${filename}${parentPath ? ` from ${
       parentPath}` : ''} not supported.`;
     if (!packageJsonPath) {
diff --git a/lib/internal/modules/cjs/helpers.js b/lib/internal/modules/cjs/helpers.js
index 6d229a0422ea12..16dd59747e23fc 100644
--- a/lib/internal/modules/cjs/helpers.js
+++ b/lib/internal/modules/cjs/helpers.js
@@ -30,13 +30,7 @@ let debug = require('internal/util/debuglog').debuglog('module', (fn) => {
   debug = fn;
 });
 
-const acorn = require('internal/deps/acorn/acorn/dist/acorn');
-const privateMethods =
-  require('internal/deps/acorn-plugins/acorn-private-methods/index');
-const classFields =
-  require('internal/deps/acorn-plugins/acorn-class-fields/index');
-const staticClassFeatures =
-  require('internal/deps/acorn-plugins/acorn-static-class-features/index');
+const parser = require('internal/deps/acorn/acorn/dist/acorn').Parser;
 
 // TODO: Use this set when resolving pkg#exports conditions in loader.js.
 const cjsConditions = new SafeSet(['require', 'node', ...userConditions]);
@@ -195,11 +189,6 @@ function normalizeReferrerURL(referrer) {
 
 // For error messages only - used to check if ESM syntax is in use.
 function hasEsmSyntax(code) {
-  const parser = acorn.Parser.extend(
-    privateMethods,
-    classFields,
-    staticClassFeatures
-  );
   let root;
   try {
     root = parser.parse(code, { sourceType: 'module', ecmaVersion: 'latest' });

From af548b5f71f78d121bca878b2c7aae860e93ada1 Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Thu, 8 Jul 2021 13:01:57 -0700
Subject: [PATCH 08/17] fixup: tests

---
 test/parallel/test-bootstrap-modules.js | 1 +
 test/parallel/test-require-mjs.js       | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/test/parallel/test-bootstrap-modules.js b/test/parallel/test-bootstrap-modules.js
index 0ca00f31adce8c..e87ce89ae25e90 100644
--- a/test/parallel/test-bootstrap-modules.js
+++ b/test/parallel/test-bootstrap-modules.js
@@ -50,6 +50,7 @@ const expectedModules = new Set([
   'NativeModule internal/console/constructor',
   'NativeModule internal/console/global',
   'NativeModule internal/constants',
+  'NativeModule internal/deps/acorn/acorn/dist/acorn',
   'NativeModule internal/encoding',
   'NativeModule internal/errors',
   'NativeModule internal/event_target',
diff --git a/test/parallel/test-require-mjs.js b/test/parallel/test-require-mjs.js
index 69f8527555db71..112f08879d4290 100644
--- a/test/parallel/test-require-mjs.js
+++ b/test/parallel/test-require-mjs.js
@@ -5,7 +5,7 @@ const assert = require('assert');
 assert.throws(
   () => require('../fixtures/es-modules/test-esm-ok.mjs'),
   {
-    message: /Must use import to load ES Module/,
+    message: /dynamic import\(\) which is available in all CommonJS modules/,
     code: 'ERR_REQUIRE_ESM'
   }
 );

From cfe3db93161a228ac83daad097d2694449911b50 Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Mon, 12 Jul 2021 23:59:35 +0200
Subject: [PATCH 09/17] fixup: code review

Co-authored-by: Antoine du Hamel <duhamelantoine1995@gmail.com>
---
 lib/internal/modules/cjs/loader.js  | 4 ++--
 test/es-module/test-cjs-esm-warn.js | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/internal/modules/cjs/loader.js b/lib/internal/modules/cjs/loader.js
index 41cae1d83282cc..b5c62035dbdee2 100644
--- a/lib/internal/modules/cjs/loader.js
+++ b/lib/internal/modules/cjs/loader.js
@@ -1134,9 +1134,9 @@ Module._extensions['.js'] = function(module, filename) {
         } catch {}
         if (parentSource) {
           const errLine = StringPrototypeSplit(StringPrototypeSlice(
-            err.stack, StringPrototypeIndexOf(err.stack, '    at ')), '\n')[0];
+            err.stack, StringPrototypeIndexOf(err.stack, '    at ')), '\n', 1)[0];
           const { 1: line, 2: col } =
-              StringPrototypeMatch(errLine, /(\d+):(\d+)\)/) || [];
+              RegExpPrototypeExec(/(\d+):(\d+)\)/, errLine) || [];
           if (line && col) {
             const srcLine = StringPrototypeSplit(parentSource, '\n')[line - 1];
             const frame = `${parentPath}:${line}\n${srcLine}\n${
diff --git a/test/es-module/test-cjs-esm-warn.js b/test/es-module/test-cjs-esm-warn.js
index cdda3ed9064d6c..3f0cf092501fa6 100644
--- a/test/es-module/test-cjs-esm-warn.js
+++ b/test/es-module/test-cjs-esm-warn.js
@@ -27,7 +27,7 @@ const pjson = path.resolve(
     assert.strictEqual(code, 1);
     assert.strictEqual(signal, null);
 
-    assert.ok(stderr.replace(/\r/g, '').includes(
+    assert.ok(stderr.replaceAll('\r', '').includes(
       `Error [ERR_REQUIRE_ESM]: require() of ES Module ${required} from ${
         requiringCjsAsEsm} not supported.\n`));
     assert.ok(stderr.includes(

From 78640e481584f873d79f64f4765c97898705bfe5 Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Mon, 12 Jul 2021 15:00:35 -0700
Subject: [PATCH 10/17] fixup: builtin require

---
 lib/internal/modules/cjs/loader.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/internal/modules/cjs/loader.js b/lib/internal/modules/cjs/loader.js
index b5c62035dbdee2..7e1cf1a7ef7207 100644
--- a/lib/internal/modules/cjs/loader.js
+++ b/lib/internal/modules/cjs/loader.js
@@ -48,6 +48,7 @@ const {
   Proxy,
   ReflectApply,
   ReflectSet,
+  RegExpPrototypeExec,
   RegExpPrototypeTest,
   SafeMap,
   SafeWeakMap,

From 16b687cf8f49e4a6180e9f47336876a3911703c6 Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Tue, 13 Jul 2021 00:01:49 +0200
Subject: [PATCH 11/17] fixup: ERR_REQUIRE_ESM recommend "type": "commonjs"

Co-authored-by: Antoine du Hamel <duhamelantoine1995@gmail.com>
---
 test/es-module/test-cjs-esm-warn.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/es-module/test-cjs-esm-warn.js b/test/es-module/test-cjs-esm-warn.js
index 3f0cf092501fa6..1b2524400b812b 100644
--- a/test/es-module/test-cjs-esm-warn.js
+++ b/test/es-module/test-cjs-esm-warn.js
@@ -33,7 +33,7 @@ const pjson = path.resolve(
     assert.ok(stderr.includes(
       `Instead rename ${basename} to end in .cjs, change the requiring ` +
       'code to use dynamic import() which is available in all CommonJS ' +
-      `modules, or remove "type": "module" from ${pjson} to ` +
+      `modules, or change "type": "module" to "type": "commonjs" from ${pjson} to ` +
       'treat all .js files as CommonJS (using .mjs for all ES modules ' +
       'instead).\n'));
   }));

From e628c0a7f198c5e7aa0b58d9fd0d50d44a7c62fb Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Mon, 12 Jul 2021 15:05:05 -0700
Subject: [PATCH 12/17] fixup: line length

---
 lib/internal/modules/cjs/loader.js | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/internal/modules/cjs/loader.js b/lib/internal/modules/cjs/loader.js
index 7e1cf1a7ef7207..31ab3a8ee9c86f 100644
--- a/lib/internal/modules/cjs/loader.js
+++ b/lib/internal/modules/cjs/loader.js
@@ -1134,8 +1134,9 @@ Module._extensions['.js'] = function(module, filename) {
           parentSource = fs.readFileSync(parentPath, 'utf8');
         } catch {}
         if (parentSource) {
-          const errLine = StringPrototypeSplit(StringPrototypeSlice(
-            err.stack, StringPrototypeIndexOf(err.stack, '    at ')), '\n', 1)[0];
+          const errLine = StringPrototypeSplit(
+            StringPrototypeSlice(err.stack, StringPrototypeIndexOf(
+              err.stack, '    at ')), '\n', 1)[0];
           const { 1: line, 2: col } =
               RegExpPrototypeExec(/(\d+):(\d+)\)/, errLine) || [];
           if (line && col) {

From 12b200942de5ea192a57b3c08ed57c694a5c9ab8 Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Mon, 12 Jul 2021 17:11:58 -0700
Subject: [PATCH 13/17] fixup: tests

---
 lib/internal/errors.js              | 6 +++---
 test/es-module/test-cjs-esm-warn.js | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/internal/errors.js b/lib/internal/errors.js
index 3a46157b2e3503..56a0ef8fb06a14 100644
--- a/lib/internal/errors.js
+++ b/lib/internal/errors.js
@@ -1461,9 +1461,9 @@ E('ERR_REQUIRE_ESM',
       'which declares all .js files in that package scope as ES modules.' +
       `\nInstead rename ${basename} to end in .cjs, change the requiring ` +
       'code to use dynamic import() which is available in all CommonJS ' +
-      `modules, or remove "type": "module" from ${packageJsonPath} to ` +
-      'treat all .js files as CommonJS (using .mjs for all ES modules ' +
-      'instead).\n';
+      'modules, or change "type": "module" to "type": "commonjs" in ' +
+      `${packageJsonPath} to treat all .js files as CommonJS (using .mjs for ` +
+      'all ES modules instead).\n';
     return msg;
   }, Error);
 E('ERR_SCRIPT_EXECUTION_INTERRUPTED',
diff --git a/test/es-module/test-cjs-esm-warn.js b/test/es-module/test-cjs-esm-warn.js
index 1b2524400b812b..214b5982d9be10 100644
--- a/test/es-module/test-cjs-esm-warn.js
+++ b/test/es-module/test-cjs-esm-warn.js
@@ -33,7 +33,7 @@ const pjson = path.resolve(
     assert.ok(stderr.includes(
       `Instead rename ${basename} to end in .cjs, change the requiring ` +
       'code to use dynamic import() which is available in all CommonJS ' +
-      `modules, or change "type": "module" to "type": "commonjs" from ${pjson} to ` +
+      `modules, or change "type": "module" to "type": "commonjs" in ${pjson} to ` +
       'treat all .js files as CommonJS (using .mjs for all ES modules ' +
       'instead).\n'));
   }));

From 8871f4e87598f522635a3bc9d8cdf96a96f57d81 Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Wed, 14 Jul 2021 12:44:37 -0700
Subject: [PATCH 14/17] fixup: windows tests

---
 test/es-module/test-cjs-esm-warn.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/es-module/test-cjs-esm-warn.js b/test/es-module/test-cjs-esm-warn.js
index 214b5982d9be10..ade841b741db77 100644
--- a/test/es-module/test-cjs-esm-warn.js
+++ b/test/es-module/test-cjs-esm-warn.js
@@ -35,7 +35,7 @@ const pjson = path.resolve(
       'code to use dynamic import() which is available in all CommonJS ' +
       `modules, or change "type": "module" to "type": "commonjs" in ${pjson} to ` +
       'treat all .js files as CommonJS (using .mjs for all ES modules ' +
-      'instead).\n'));
+      'instead).'));
   }));
 }
 

From dfd2397a08dc077ade56859a35a338aedb6759c5 Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Wed, 14 Jul 2021 15:12:05 -0700
Subject: [PATCH 15/17] fixup: more windows fixes

---
 test/es-module/test-cjs-esm-warn.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/test/es-module/test-cjs-esm-warn.js b/test/es-module/test-cjs-esm-warn.js
index ade841b741db77..d7eeb65b152a4a 100644
--- a/test/es-module/test-cjs-esm-warn.js
+++ b/test/es-module/test-cjs-esm-warn.js
@@ -30,12 +30,12 @@ const pjson = path.resolve(
     assert.ok(stderr.replaceAll('\r', '').includes(
       `Error [ERR_REQUIRE_ESM]: require() of ES Module ${required} from ${
         requiringCjsAsEsm} not supported.\n`));
-    assert.ok(stderr.includes(
+    assert.ok(stderr.replaceAll('\r', '').includes(
       `Instead rename ${basename} to end in .cjs, change the requiring ` +
       'code to use dynamic import() which is available in all CommonJS ' +
       `modules, or change "type": "module" to "type": "commonjs" in ${pjson} to ` +
       'treat all .js files as CommonJS (using .mjs for all ES modules ' +
-      'instead).'));
+      'instead).\n'));
   }));
 }
 
@@ -57,7 +57,7 @@ const pjson = path.resolve(
     assert.ok(stderr.replace(/\r/g, '').includes(
       `Error [ERR_REQUIRE_ESM]: require() of ES Module ${required} from ${
         requiringEsm} not supported.\n`));
-    assert.ok(stderr.includes(
+    assert.ok(stderr.replace(/\r/g, '').includes(
       `Instead change the require of ${basename} in ${requiringEsm} to` +
       ' a dynamic import() which is available in all CommonJS modules.\n'));
   }));

From b156244365bbd30d11cdf712a232f5d1b9926372 Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Wed, 14 Jul 2021 19:20:48 -0700
Subject: [PATCH 16/17] fixup: lazily load acorn

---
 lib/internal/modules/cjs/helpers.js | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/lib/internal/modules/cjs/helpers.js b/lib/internal/modules/cjs/helpers.js
index 16dd59747e23fc..bac854e0fadbac 100644
--- a/lib/internal/modules/cjs/helpers.js
+++ b/lib/internal/modules/cjs/helpers.js
@@ -30,8 +30,6 @@ let debug = require('internal/util/debuglog').debuglog('module', (fn) => {
   debug = fn;
 });
 
-const parser = require('internal/deps/acorn/acorn/dist/acorn').Parser;
-
 // TODO: Use this set when resolving pkg#exports conditions in loader.js.
 const cjsConditions = new SafeSet(['require', 'node', ...userConditions]);
 
@@ -189,6 +187,7 @@ function normalizeReferrerURL(referrer) {
 
 // For error messages only - used to check if ESM syntax is in use.
 function hasEsmSyntax(code) {
+  const parser = require('internal/deps/acorn/acorn/dist/acorn').Parser;
   let root;
   try {
     root = parser.parse(code, { sourceType: 'module', ecmaVersion: 'latest' });

From cf5879f4ed6af519d4911b018ba780f44dea7e2e Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Wed, 14 Jul 2021 19:55:54 -0700
Subject: [PATCH 17/17] fixup: bootstrap list

---
 test/parallel/test-bootstrap-modules.js | 1 -
 1 file changed, 1 deletion(-)

diff --git a/test/parallel/test-bootstrap-modules.js b/test/parallel/test-bootstrap-modules.js
index e87ce89ae25e90..0ca00f31adce8c 100644
--- a/test/parallel/test-bootstrap-modules.js
+++ b/test/parallel/test-bootstrap-modules.js
@@ -50,7 +50,6 @@ const expectedModules = new Set([
   'NativeModule internal/console/constructor',
   'NativeModule internal/console/global',
   'NativeModule internal/constants',
-  'NativeModule internal/deps/acorn/acorn/dist/acorn',
   'NativeModule internal/encoding',
   'NativeModule internal/errors',
   'NativeModule internal/event_target',