implement bugfix plugin

Makefile

@@ -186,15 +186,15 @@ prepublish:
 	IS_PUBLISH=true $(MAKE) test
 
 new-version-checklist:
-	# @echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
-	# @echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
-	# @echo "!!!!!!                                                   !!!!!!"
-	# @echo "!!!!!!         Write any message that should             !!!!!!"
-	# @echo "!!!!!!            block the release here                 !!!!!!"
-	# @echo "!!!!!!                                                   !!!!!!"
-	# @echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
-	# @echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
-	# @exit 1
+	@echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
+	@echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
+	@echo "!!!!!!                                                   !!!!!!"
+	@echo "!!!!!!  Set packages/babel-plugin-bugfix-webkit-id-destructuring-collision-in-function-expression/package.json"
+	@echo "!!!!!!  @babel/core peerDependencies to latest published version"
+	@echo "!!!!!!                                                   !!!!!!"
+	@echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
+	@echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
+	@exit 1
 
 new-version:
 	$(MAKE) new-version-checklist

packages/babel-plugin-bugfix-v8-spread-parameters-in-optional-chaining/test/util.test.js

@@ -5,15 +5,7 @@ function getPath(input, parserOpts = {}) {
   let targetPath;
   traverse(
     parseSync(input, {
-      parserOpts: {
-        plugins: [
-          "classPrivateMethods",
-          "classPrivateProperties",
-          "classProperties",
-          ...(parserOpts.plugins || []),
-        ],
-        ...parserOpts,
-      },
+      parserOpts,
       filename: "example.js",
       configFile: false,
     }),

packages/babel-plugin-bugfix-webkit-id-destructuring-collision-in-function-expression/.npmignore

@@ -0,0 +1,3 @@
+src
+test
+*.log

packages/babel-plugin-bugfix-webkit-id-destructuring-collision-in-function-expression/README.md

@@ -0,0 +1,19 @@
+# @babel/plugin-bugfix-webkit-id-destructuring-collision-in-function-expression
+
+> Transform optional chaining operators to workaround a [v8 bug](https://crbug.com/v8/11558).
+
+See our website [@babel/plugin-bugfix-webkit-id-destructuring-collision-in-function-expression](https://babeljs.io/docs/en/babel-plugin-bugfix-webkit-id-destructuring-collision-in-function-expression) for more information.
+
+## Install
+
+Using npm:
+
+```sh
+npm install --save-dev @babel/plugin-bugfix-webkit-id-destructuring-collision-in-function-expression
+```
+
+or using yarn:
+
+```sh
+yarn add @babel/plugin-bugfix-webkit-id-destructuring-collision-in-function-expression --dev
+```

packages/babel-plugin-bugfix-webkit-id-destructuring-collision-in-function-expression/package.json

@@ -0,0 +1,40 @@
+{
+  "name": "@babel/plugin-bugfix-webkit-id-destructuring-collision-in-function-expression",
+  "version": "0.0.0",
+  "description": "Rename destructuring parameter to workaround https://bugs.webkit.org/show_bug.cgi?id=220517",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/babel/babel.git",
+    "directory": "packages/babel-plugin-bugfix-webkit-id-destructuring-collision-in-function-expression"
+  },
+  "homepage": "https://babel.dev/docs/en/next/babel-plugin-bugfix-webkit-id-destructuring-collision-in-function-expression",
+  "license": "MIT",
+  "publishConfig": {
+    "access": "public"
+  },
+  "main": "./lib/index.js",
+  "exports": {
+    ".": [
+      "./lib/index.js"
+    ]
+  },
+  "keywords": [
+    "babel-plugin",
+    "bugfix"
+  ],
+  "dependencies": {
+    "@babel/helper-plugin-utils": "workspace:^7.14.5"
+  },
+  "peerDependencies": {
+    "@babel/core": "^7.15.0"
+  },
+  "devDependencies": {
+    "@babel/core": "workspace:*",
+    "@babel/helper-plugin-test-runner": "workspace:*",
+    "@babel/traverse": "workspace:*"
+  },
+  "engines": {
+    "node": ">=6.9.0"
+  },
+  "author": "The Babel Team (https://babel.dev/team)"
+}

packages/babel-plugin-bugfix-webkit-id-destructuring-collision-in-function-expression/src/index.ts

@@ -0,0 +1,25 @@
+import { declare } from "@babel/helper-plugin-utils";
+import type { PluginPass } from "@babel/core";
+import type { Visitor } from "@babel/traverse";
+import { shouldTransform } from "./util";
+
+export default declare(api => {
+  api.assertVersion(7);
+
+  return {
+    name: "plugin-bugfix-webkit-id-destructuring-collision-in-function-expression",
+
+    visitor: {
+      FunctionExpression(path) {
+        const name = shouldTransform(path);
+        if (name) {
+          // Now we have (function a([a]) {})
+          const { scope } = path;
+          // invariant: path.node.id is always an Identifier here
+          const newParamName = scope.generateUid(name);
+          scope.rename(name, newParamName);
+        }
+      },
+    } as Visitor<PluginPass>,
+  };
+});

packages/babel-plugin-bugfix-webkit-id-destructuring-collision-in-function-expression/src/util.ts

@@ -0,0 +1,41 @@
+import type { FunctionExpression } from "@babel/types";
+import type { NodePath } from "@babel/traverse";
+
+/**
+ * Check whether a function expression can be affected by
+ * https://bugs.webkit.org/show_bug.cgi?id=220517
+ * @param path The function expression NodePath
+ * @returns the name of function id if it should be transformed, otherwise returns false
+ */
+export function shouldTransform(
+  path: NodePath<FunctionExpression>,
+): string | false {
+  const { node } = path;
+  const functionId = node.id;
+  if (!functionId) return false;
+
+  const name = functionId.name;
+  // On collision, `getOwnBinding` returns the param binding
+  // with the id binding be registered as constant violation
+  const paramNameBinding = path.scope.getOwnBinding(name);
+  const constantViolations = paramNameBinding.constantViolations;
+  if (constantViolations.length === 0) {
+    // the function scope has no such collided bindings
+    return false;
+  }
+  const firstViolation = constantViolations[0];
+
+  if (firstViolation.node !== node) {
+    // the violation does not happen in id
+    // e.g. (function a() { var a; })
+    return false;
+  }
+
+  if (paramNameBinding.identifier === paramNameBinding.path.node) {
+    // the param binding is a simple parameter
+    // e.g. (function a(a) {})
+    return false;
+  }
+
+  return name;
+}

packages/babel-plugin-bugfix-webkit-id-destructuring-collision-in-function-expression/test/fixtures/basic/avoid-collision/input.mjs

@@ -0,0 +1 @@
+(function a([a, _a]) { a + _a })

packages/babel-plugin-bugfix-webkit-id-destructuring-collision-in-function-expression/test/fixtures/basic/avoid-collision/output.mjs

@@ -0,0 +1,3 @@
+(function a([_a2, _a]) {
+  _a2 + _a;
+});

packages/babel-plugin-bugfix-webkit-id-destructuring-collision-in-function-expression/test/fixtures/basic/basic/input.mjs

@@ -0,0 +1 @@
+(function a([a]) { a })

packages/babel-plugin-bugfix-webkit-id-destructuring-collision-in-function-expression/test/fixtures/basic/basic/output.mjs

@@ -0,0 +1,3 @@
+(function a([_a]) {
+  _a;
+});

packages/babel-plugin-bugfix-webkit-id-destructuring-collision-in-function-expression/test/fixtures/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["bugfix-webkit-id-destructuring-collision-in-function-expression"]
+}

packages/babel-plugin-bugfix-webkit-id-destructuring-collision-in-function-expression/test/index.js

@@ -0,0 +1,3 @@
+import runner from "@babel/helper-plugin-test-runner";
+
+runner(import.meta.url);

packages/babel-plugin-bugfix-webkit-id-destructuring-collision-in-function-expression/test/util.test.js

@@ -0,0 +1,51 @@
+import { parseSync, traverse } from "@babel/core";
+import { shouldTransform } from "../src/util.ts";
+
+function getPath(input, parserOpts = {}) {
+  let targetPath;
+  traverse(
+    parseSync(input, {
+      parserOpts,
+      filename: "example.js",
+      configFile: false,
+    }),
+    {
+      FunctionExpression(path) {
+        targetPath = path;
+        path.stop();
+      },
+    },
+  );
+  return targetPath;
+}
+
+describe("shouldTransform", () => {
+  const positiveCases = [
+    "(function a([a]) {})",
+    "({ b: function a([a]) {} })",
+    "(function a({a}) {})",
+    "(function a(...a) {})",
+    "(function a([a = 1]) {})",
+  ];
+
+  const negativeCases = [
+    "(function () {})",
+    "(function a() {})",
+    "(function a(a) {})",
+    "(function a() { var a })",
+    "(function a(x = a) {})",
+    "(function a() { var { a } = {}; })",
+  ];
+
+  describe("default parser options", () => {
+    test.each(positiveCases)("shouldTransform(%p) should return 'a'", input => {
+      expect(shouldTransform(getPath(input))).toBe("a");
+    });
+    test.each(negativeCases)(
+      "shouldTransform(in %p) should return false",
+      input => {
+        expect(shouldTransform(getPath(input))).toBe(false);
+      },
+    );
+  });
+});

tsconfig.json

@@ -28,6 +28,7 @@
     "./packages/babel-helpers/src/**/*.ts",
     "./packages/babel-highlight/src/**/*.ts",
     "./packages/babel-plugin-bugfix-v8-spread-parameters-in-optional-chaining/src/**/*.ts",
+    "./packages/babel-plugin-bugfix-webkit-id-destructuring-collision-in-function-expression/src/**/*.ts",
     "./packages/babel-plugin-proposal-async-do-expressions/src/**/*.ts",
     "./packages/babel-plugin-syntax-async-do-expressions/src/**/*.ts",
     "./packages/babel-plugin-transform-block-scoping/src/**/*.ts",
@@ -122,6 +123,9 @@
       "@babel/plugin-bugfix-v8-spread-parameters-in-optional-chaining": [
         "./packages/babel-plugin-bugfix-v8-spread-parameters-in-optional-chaining/src"
       ],
+      "@babel/plugin-bugfix-webkit-id-destructuring-collision-in-function-expression": [
+        "./packages/babel-plugin-bugfix-webkit-id-destructuring-collision-in-function-expression/src"
+      ],
       "@babel/plugin-proposal-async-do-expressions": [
         "./packages/babel-plugin-proposal-async-do-expressions/src"
       ],

yarn.lock

@@ -1057,6 +1057,19 @@ __metadata:
   languageName: unknown
   linkType: soft
 
+"@babel/plugin-bugfix-webkit-id-destructuring-collision-in-function-expression@workspace:packages/babel-plugin-bugfix-webkit-id-destructuring-collision-in-function-expression":
+  version: 0.0.0-use.local
+  resolution: "@babel/plugin-bugfix-webkit-id-destructuring-collision-in-function-expression@workspace:packages/babel-plugin-bugfix-webkit-id-destructuring-collision-in-function-expression"
+  dependencies:
+    "@babel/core": "workspace:*"
+    "@babel/helper-plugin-test-runner": "workspace:*"
+    "@babel/helper-plugin-utils": "workspace:^7.14.5"
+    "@babel/traverse": "workspace:*"
+  peerDependencies:
+    "@babel/core": ^7.15.0
+  languageName: unknown
+  linkType: soft
+
 "@babel/plugin-codemod-object-assign-to-object-spread@workspace:codemods/babel-plugin-codemod-object-assign-to-object-spread":
   version: 0.0.0-use.local
   resolution: "@babel/plugin-codemod-object-assign-to-object-spread@workspace:codemods/babel-plugin-codemod-object-assign-to-object-spread"