Implement @babel/plugin-bugfix-safari-id-destructuring-collision-in-function-expression

Gulpfile.mjs

@@ -465,6 +465,7 @@ const libBundles = [
   "packages/babel-preset-typescript",
   "packages/babel-helper-member-expression-to-functions",
   "packages/babel-plugin-bugfix-v8-spread-parameters-in-optional-chaining",
+  "packages/babel-plugin-bugfix-safari-id-destructuring-collision-in-function-expression",
 ].map(src => ({
   src,
   format: "cjs",

Makefile

@@ -186,15 +186,17 @@ 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 "!!!!!!  packages/babel-plugin-bugfix-safari-id-destructuring-collision-in-function-expression/src/index.ts"
+	@echo "!!!!!!  replace \"api.assertVersion()\" to the latest published version"
+	@echo "!!!!!!  packages/babel-preset-env/src/available-plugins.ts:"
+	@echo "!!!!!!  replace minVersion[\"bugfix/transform-v8-spread-parameters-in-optional-chaining\"] to the latest published version"
+	@echo "!!!!!!                                                   !!!!!!"
+	@echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
+	@echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
+	@exit 1
 
 new-version:
 	$(MAKE) new-version-checklist

packages/babel-compat-data/data/overlapping-plugins.json

@@ -3,7 +3,8 @@
     "bugfix/transform-async-arrows-in-class"
   ],
   "transform-parameters": [
-    "bugfix/transform-edge-default-parameters"
+    "bugfix/transform-edge-default-parameters",
+    "bugfix/transform-safari-id-destructuring-collision-in-function-expression"
   ],
   "transform-function-name": [
     "bugfix/transform-edge-function-name"

packages/babel-compat-data/data/plugin-bugfixes.json

@@ -101,6 +101,16 @@
     "rhino": "1.7.13",
     "electron": "0.37"
   },
+  "bugfix/transform-safari-id-destructuring-collision-in-function-expression": {
+    "chrome": "49",
+    "opera": "36",
+    "edge": "14",
+    "firefox": "2",
+    "node": "6",
+    "samsung": "5",
+    "rhino": "1.7.13",
+    "electron": "0.37"
+  },
   "transform-template-literals": {
     "chrome": "41",
     "opera": "28",
@@ -135,8 +145,10 @@
     "electron": "8.0"
   },
   "bugfix/transform-v8-spread-parameters-in-optional-chaining": {
+    "chrome": "91",
     "firefox": "74",
     "safari": "13.1",
-    "ios": "13.4"
+    "ios": "13.4",
+    "electron": "13.0"
   }
 }

packages/babel-compat-data/data/plugins.json

@@ -1,11 +1,13 @@
 {
   "proposal-class-static-block": {
-    "chrome": "91",
-    "electron": "13.0"
+    "chrome": "94",
+    "firefox": "93"
   },
   "proposal-private-property-in-object": {
     "chrome": "91",
     "firefox": "90",
+    "safari": "15",
+    "ios": "15",
     "electron": "13.0"
   },
   "proposal-class-properties": {
@@ -15,6 +17,7 @@
     "firefox": "90",
     "safari": "14.1",
     "node": "12",
+    "ios": "15",
     "samsung": "11",
     "electron": "6.0"
   },
@@ -25,6 +28,8 @@
     "firefox": "90",
     "safari": "15",
     "node": "14.6",
+    "ios": "15",
+    "samsung": "14",
     "electron": "10.0"
   },
   "proposal-numeric-separator": {
@@ -46,6 +51,7 @@
     "safari": "14",
     "node": "15",
     "ios": "14",
+    "samsung": "14",
     "electron": "10.0"
   },
   "proposal-nullish-coalescing-operator": {
@@ -60,9 +66,11 @@
     "electron": "8.0"
   },
   "proposal-optional-chaining": {
+    "chrome": "91",
     "firefox": "74",
     "safari": "13.1",
-    "ios": "13.4"
+    "ios": "13.4",
+    "electron": "13.0"
   },
   "proposal-json-strings": {
     "chrome": "66",
@@ -91,9 +99,7 @@
     "opera": "36",
     "edge": "18",
     "firefox": "53",
-    "safari": "10",
     "node": "6",
-    "ios": "10",
     "samsung": "5",
     "electron": "0.37"
   },
@@ -379,7 +385,7 @@
     "chrome": "46",
     "opera": "33",
     "edge": "14",
-    "firefox": "45",
+    "firefox": "41",
     "safari": "10",
     "node": "5",
     "ios": "10",

packages/babel-compat-data/scripts/data/plugin-bugfixes.js

@@ -31,6 +31,10 @@ module.exports = {
     ],
     replaces: "transform-block-scoping",
   },
+  "bugfix/transform-safari-id-destructuring-collision-in-function-expression": {
+    features: ["destructuring, parameters / duplicate identifier"],
+    replaces: "transform-parameters",
+  },
   "bugfix/transform-tagged-template-caching": {
     features: ["template literals / TemplateStrings permanent caching"],
     replaces: "transform-template-literals",

packages/babel-compat-data/scripts/data/plugin-features.js

@@ -18,6 +18,7 @@ const es2015Parameter = {
       "rest parameters",
       "destructuring, parameters / aliased defaults, arrow function",
       "destructuring, parameters / shorthand defaults, arrow function",
+      "destructuring, parameters / duplicate identifier",
     ],
   },
 };

packages/babel-compat-data/scripts/download-compat-table.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 set -e
 
-COMPAT_TABLE_COMMIT=63abfe227f4b9c6ef019efbbf059025b537b8511
+COMPAT_TABLE_COMMIT=34b14f8eb016f8f2f3312adf35c53d6364742582
 GIT_HEAD=build/compat-table/.git/HEAD
 
 if [ -d "build/compat-table" ]; then

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

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

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

@@ -0,0 +1,19 @@
+# @babel/plugin-bugfix-safari-id-destructuring-collision-in-function-expression
+
+> Rename destructuring parameter to workaround a [Safari bug](https://bugs.webkit.org/show_bug.cgi?id=220517).
+
+See our website [@babel/plugin-bugfix-safari-id-destructuring-collision-in-function-expression](https://babeljs.io/docs/en/babel-plugin-bugfix-safari-id-destructuring-collision-in-function-expression) for more information.
+
+## Install
+
+Using npm:
+
+```sh
+npm install --save-dev @babel/plugin-bugfix-safari-id-destructuring-collision-in-function-expression
+```
+
+or using yarn:
+
+```sh
+yarn add @babel/plugin-bugfix-safari-id-destructuring-collision-in-function-expression --dev
+```

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

@@ -0,0 +1,40 @@
+{
+  "name": "@babel/plugin-bugfix-safari-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-safari-id-destructuring-collision-in-function-expression"
+  },
+  "homepage": "https://babel.dev/docs/en/next/babel-plugin-bugfix-safari-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": "^7.0.0"
+  },
+  "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-safari-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("^7.15.0");
+
+  return {
+    name: "plugin-bugfix-safari-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-safari-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-safari-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-safari-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-safari-id-destructuring-collision-in-function-expression/test/fixtures/basic/basic/input.mjs

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

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

@@ -0,0 +1,14 @@
+(function a([_a]) {
+  _a;
+});
+
+(function a({ ..._a2
+}) {
+  _a2;
+});
+
+(function a({
+  a: _a3
+}) {
+  _a3;
+});

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

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

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

@@ -0,0 +1,56 @@
+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 }) {})",
+    "(function a([a = 1]) {})",
+    "(function a(b, { a: [,...a] }) {})",
+  ];
+
+  const negativeCases = [
+    "(function () {})",
+    "(function a() {})",
+    "(function a(a) {})",
+    "(function a() { var a })",
+    "(function b([a]) { var a })",
+    "(function b([a]) { function a() {} })",
+    "(function a(x = a) {})",
+    "(function a() { var { a } = {}; })",
+    "(function b([a]) { var { a } = {}; })",
+    "(function a({ [a]: b }) {})",
+  ];
+
+  describe("the following cases should be transformed", () => {
+    test.each(positiveCases)("%p", input => {
+      expect(shouldTransform(getPath(input))).toBe("a");
+    });
+  });
+  describe("the following cases should not be transformed", () => {
+    test.each(negativeCases)("%p", input => {
+      expect(shouldTransform(getPath(input))).toBe(false);
+    });
+  });
+});