feat: Support regexp modifiers proposal (#15226)

Co-authored-by: Nicolò Ribaudo <nicolo.ribaudo@gmail.com>

lib/regexpu-core.d.ts

@@ -6,6 +6,8 @@ declare module "regexpu-core" {
     unicodePropertyEscapes?: "transform" | false;
     namedGroups?: "transform" | false;
     onNamedGroup?: (name: string, index: number) => void;
+    modifiers?: "transform" | false;
+    onNewFlags?: (name: string) => void;
   };
   function rewritePattern(
     pattern: string,

packages/babel-helper-create-regexp-features-plugin/package.json

@@ -19,7 +19,7 @@
   ],
   "dependencies": {
     "@babel/helper-annotate-as-pure": "workspace:^",
-    "regexpu-core": "^5.2.1"
+    "regexpu-core": "^5.3.1"
   },
   "peerDependencies": {
     "@babel/core": "^7.0.0"

packages/babel-helper-create-regexp-features-plugin/src/features.ts

@@ -6,6 +6,7 @@ export const FEATURES = Object.freeze({
   unicodeSetsFlag_syntax: 1 << 4,
   unicodeSetsFlag: 1 << 5,
   duplicateNamedCaptureGroups: 1 << 6,
+  modifiers: 1 << 7,
 });
 
 // We can't use a symbol because this needs to always be the same, even if

packages/babel-helper-create-regexp-features-plugin/src/index.ts

@@ -116,6 +116,13 @@ export function createRegExpFeaturePlugin({
           };
         }
 
+        let newFlags;
+        if (regexpuOptions.modifiers === "transform") {
+          regexpuOptions.onNewFlags = flags => {
+            newFlags = flags;
+          };
+        }
+
         node.pattern = rewritePattern(node.pattern, node.flags, regexpuOptions);
 
         if (
@@ -133,7 +140,7 @@ export function createRegExpFeaturePlugin({
           path.replaceWith(call);
         }
 
-        node.flags = transformFlags(regexpuOptions, node.flags);
+        node.flags = transformFlags(regexpuOptions, newFlags ?? node.flags);
       },
     },
   };

packages/babel-helper-create-regexp-features-plugin/src/util.ts

@@ -40,6 +40,7 @@ export function generateRegexpuOptions(
     unicodePropertyEscapes: feat("unicodePropertyEscape"),
     namedGroups: feat("namedCaptureGroups") || featDuplicateNamedGroups(),
     onNamedGroup: () => {},
+    modifiers: feat("modifiers"),
   };
 }
 
@@ -71,6 +72,10 @@ export function canSkipRegexpu(
     return false;
   }
 
+  if (options.modifiers === "transform" && /\(\?[\w-]+:/.test(pattern)) {
+    return false;
+  }
+
   return true;
 }
 

packages/babel-plugin-proposal-regexp-modifiers/.npmignore

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

packages/babel-plugin-proposal-regexp-modifiers/README.md

@@ -0,0 +1,19 @@
+# @babel/plugin-proposal-regexp-modifiers
+
+> Compile regular expressions using duplicate named groups to index-based groups.
+
+See our website [@babel/plugin-proposal-regexp-modifiers](https://babeljs.io/docs/en/babel-plugin-proposal-regexp-modifiers) for more information.
+
+## Install
+
+Using npm:
+
+```sh
+npm install --save-dev @babel/plugin-proposal-regexp-modifiers
+```
+
+or using yarn:
+
+```sh
+yarn add @babel/plugin-proposal-regexp-modifiers --dev
+```

packages/babel-plugin-proposal-regexp-modifiers/package.json

@@ -0,0 +1,50 @@
+{
+  "name": "@babel/plugin-proposal-regexp-modifiers",
+  "version": "7.19.1",
+  "description": "Compile inline regular expression modifiers",
+  "homepage": "https://babel.dev/docs/en/next/babel-plugin-proposal-regexp-modifiers",
+  "license": "MIT",
+  "publishConfig": {
+    "access": "public"
+  },
+  "main": "./lib/index.js",
+  "keywords": [
+    "babel-plugin",
+    "regex",
+    "regexp",
+    "regular expressions"
+  ],
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/babel/babel.git",
+    "directory": "packages/babel-plugin-proposal-regexp-modifiers"
+  },
+  "bugs": "https://github.com/babel/babel/issues",
+  "dependencies": {
+    "@babel/helper-create-regexp-features-plugin": "workspace:^",
+    "@babel/helper-plugin-utils": "workspace:^"
+  },
+  "peerDependencies": {
+    "@babel/core": "^7.0.0"
+  },
+  "devDependencies": {
+    "@babel/core": "workspace:^"
+  },
+  "engines": {
+    "node": ">=6.9.0"
+  },
+  "author": "The Babel Team (https://babel.dev/team)",
+  "conditions": {
+    "USE_ESM": [
+      {
+        "type": "module"
+      },
+      null
+    ]
+  },
+  "exports": {
+    ".": "./lib/index.js",
+    "./package.json": "./package.json"
+  },
+  "type": "commonjs"
+}

packages/babel-plugin-proposal-regexp-modifiers/src/index.ts

@@ -0,0 +1,12 @@
+/* eslint-disable @babel/development/plugin-name */
+import { createRegExpFeaturePlugin } from "@babel/helper-create-regexp-features-plugin";
+import { declare } from "@babel/helper-plugin-utils";
+
+export default declare(api => {
+  api.assertVersion("^7.19.0");
+
+  return createRegExpFeaturePlugin({
+    name: "proposal-regexp-modifiers",
+    feature: "modifiers",
+  });
+});

packages/babel-plugin-proposal-regexp-modifiers/test/fixtures/syntax/with-u-flag/exec.js

@@ -0,0 +1,3 @@
+let regex = /(?ims:^[a-z])/u;
+
+expect(regex.test("\u017F")).toBeTruthy();

packages/babel-plugin-proposal-regexp-modifiers/test/fixtures/syntax/with-u-flag/input.js

@@ -0,0 +1,2 @@
+/(?ims:^[a-z])/u;
+/(?-ims:^[a-z].)(^[a-z].)/uims;

packages/babel-plugin-proposal-regexp-modifiers/test/fixtures/syntax/with-u-flag/options.json

@@ -0,0 +1,4 @@
+{
+  "plugins": ["proposal-regexp-modifiers", "transform-unicode-regex"],
+  "minNodeVersion": "8.0.0"
+}

packages/babel-plugin-proposal-regexp-modifiers/test/fixtures/syntax/without-u-flag-exec/exec.js

@@ -0,0 +1,11 @@
+let regex = /(?ims:^[a-z].1$)/
+
+expect(regex.test("Ax1")).toBeTruthy();
+expect(regex.test("ax1")).toBeTruthy();
+expect(regex.test("ax2")).toBeFalsy();
+expect(regex.test("1ax1")).toBeFalsy();
+
+expect(regex.test("a\r1")).toBeTruthy();
+expect(regex.test("a\r\n1")).toBeFalsy();
+
+expect(regex.test("\nax1\n\n\n\n\n\n\n\n\n")).toBeTruthy();

packages/babel-plugin-proposal-regexp-modifiers/test/fixtures/syntax/without-u-flag-exec/options.json

@@ -0,0 +1,4 @@
+{
+  "plugins": ["proposal-regexp-modifiers"],
+  "minNodeVersion": "8.0.0"
+}

packages/babel-plugin-proposal-regexp-modifiers/test/fixtures/syntax/without-u-flag/input.js

@@ -0,0 +1,2 @@
+/(?ims:^[a-z]1$)/;
+/(?-ims:^[a-z].1$)(^[a-z].)/ims;

packages/babel-plugin-proposal-regexp-modifiers/test/fixtures/syntax/without-u-flag/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["proposal-regexp-modifiers"]
+}

packages/babel-plugin-proposal-regexp-modifiers/test/fixtures/syntax/without-u-flag/output.js

@@ -0,0 +1,2 @@
+/(?:(?:^|(?<=[\n\r\u2028\u2029]))[A-Za-z]1(?:$|(?=[\n\r\u2028\u2029])))/;
+/(?:^[a-z].1$)((?:^|(?<=[\n\r\u2028\u2029]))[A-Za-z][\s\S])/;

packages/babel-plugin-proposal-regexp-modifiers/test/index.js

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

packages/babel-plugin-proposal-regexp-modifiers/test/package.json

@@ -0,0 +1 @@
+{ "type": "module" }

packages/babel-standalone/package.json

@@ -35,6 +35,7 @@
     "@babel/plugin-proposal-private-methods": "workspace:^",
     "@babel/plugin-proposal-private-property-in-object": "workspace:^",
     "@babel/plugin-proposal-record-and-tuple": "workspace:^",
+    "@babel/plugin-proposal-regexp-modifiers": "workspace:^",
     "@babel/plugin-proposal-throw-expressions": "workspace:^",
     "@babel/plugin-proposal-unicode-property-regex": "workspace:^",
     "@babel/plugin-proposal-unicode-sets-regex": "workspace:^",

packages/babel-standalone/scripts/pluginConfig.json

@@ -59,6 +59,7 @@
     "proposal-private-methods",
     "proposal-private-property-in-object",
     "proposal-record-and-tuple",
+    "proposal-regexp-modifiers",
     "proposal-throw-expressions",
     "proposal-unicode-property-regex",
     "proposal-unicode-sets-regex",

packages/babel-standalone/src/generated/plugins.ts

@@ -43,6 +43,7 @@ import proposalPipelineOperator from "@babel/plugin-proposal-pipeline-operator";
 import proposalPrivateMethods from "@babel/plugin-proposal-private-methods";
 import proposalPrivatePropertyInObject from "@babel/plugin-proposal-private-property-in-object";
 import proposalRecordAndTuple from "@babel/plugin-proposal-record-and-tuple";
+import proposalRegexpModifiers from "@babel/plugin-proposal-regexp-modifiers";
 import proposalThrowExpressions from "@babel/plugin-proposal-throw-expressions";
 import proposalUnicodePropertyRegex from "@babel/plugin-proposal-unicode-property-regex";
 import proposalUnicodeSetsRegex from "@babel/plugin-proposal-unicode-sets-regex";
@@ -145,6 +146,7 @@ export {
   proposalPrivateMethods,
   proposalPrivatePropertyInObject,
   proposalRecordAndTuple,
+  proposalRegexpModifiers,
   proposalThrowExpressions,
   proposalUnicodePropertyRegex,
   proposalUnicodeSetsRegex,
@@ -249,6 +251,7 @@ export const all: { [k: string]: any } = {
   "proposal-private-methods": proposalPrivateMethods,
   "proposal-private-property-in-object": proposalPrivatePropertyInObject,
   "proposal-record-and-tuple": proposalRecordAndTuple,
+  "proposal-regexp-modifiers": proposalRegexpModifiers,
   "proposal-throw-expressions": proposalThrowExpressions,
   "proposal-unicode-property-regex": proposalUnicodePropertyRegex,
   "proposal-unicode-sets-regex": proposalUnicodeSetsRegex,

packages/babel-standalone/src/preset-stage-3.ts

@@ -8,8 +8,7 @@ export default (_: any, opts: any = {}) => {
     decoratorsBeforeExport,
   } = opts;
 
-  // todo(flow->ts) improve types
-  const plugins: any[] = [
+  const plugins = [
     babelPlugins.syntaxImportAssertions,
     babelPlugins.proposalUnicodeSetsRegex,
     babelPlugins.proposalDuplicateNamedCapturingGroupsRegex,
@@ -20,23 +19,23 @@ export default (_: any, opts: any = {}) => {
         decoratorsBeforeExport,
       },
     ],
-  ];
-
-  if (!process.env.BABEL_8_BREAKING) {
+    babelPlugins.proposalRegexpModifiers,
     // These are Stage 4
-    plugins.push(
-      babelPlugins.proposalExportNamespaceFrom,
-      babelPlugins.proposalLogicalAssignmentOperators,
-      [babelPlugins.proposalOptionalChaining, { loose }],
-      [babelPlugins.proposalNullishCoalescingOperator, { loose }],
-      [babelPlugins.proposalClassProperties, { loose }],
-      babelPlugins.proposalJsonStrings,
-      babelPlugins.proposalNumericSeparator,
-      [babelPlugins.proposalPrivateMethods, { loose }],
-      babelPlugins.proposalPrivatePropertyInObject,
-      babelPlugins.proposalClassStaticBlock,
-    );
-  }
+    ...(process.env.BABEL_8_BREAKING
+      ? []
+      : [
+          babelPlugins.proposalExportNamespaceFrom,
+          babelPlugins.proposalLogicalAssignmentOperators,
+          [babelPlugins.proposalOptionalChaining, { loose }],
+          [babelPlugins.proposalNullishCoalescingOperator, { loose }],
+          [babelPlugins.proposalClassProperties, { loose }],
+          babelPlugins.proposalJsonStrings,
+          babelPlugins.proposalNumericSeparator,
+          [babelPlugins.proposalPrivateMethods, { loose }],
+          babelPlugins.proposalPrivatePropertyInObject,
+          babelPlugins.proposalClassStaticBlock,
+        ]),
+  ];
 
   return { plugins };
 };

tsconfig.json

@@ -67,6 +67,7 @@
     "./packages/babel-plugin-proposal-private-methods/src/**/*.ts",
     "./packages/babel-plugin-proposal-private-property-in-object/src/**/*.ts",
     "./packages/babel-plugin-proposal-record-and-tuple/src/**/*.ts",
+    "./packages/babel-plugin-proposal-regexp-modifiers/src/**/*.ts",
     "./packages/babel-plugin-proposal-throw-expressions/src/**/*.ts",
     "./packages/babel-plugin-proposal-unicode-property-regex/src/**/*.ts",
     "./packages/babel-plugin-proposal-unicode-sets-regex/src/**/*.ts",
@@ -367,6 +368,9 @@
       "@babel/plugin-proposal-record-and-tuple": [
         "./packages/babel-plugin-proposal-record-and-tuple/src"
       ],
+      "@babel/plugin-proposal-regexp-modifiers": [
+        "./packages/babel-plugin-proposal-regexp-modifiers/src"
+      ],
       "@babel/plugin-proposal-throw-expressions": [
         "./packages/babel-plugin-proposal-throw-expressions/src"
       ],

yarn.lock

@@ -636,7 +636,7 @@ __metadata:
     "@babel/core": "workspace:^"
     "@babel/helper-annotate-as-pure": "workspace:^"
     "@babel/helper-plugin-test-runner": "workspace:^"
-    regexpu-core: ^5.2.1
+    regexpu-core: ^5.3.1
   peerDependencies:
     "@babel/core": ^7.0.0
   languageName: unknown
@@ -1764,6 +1764,18 @@ __metadata:
   languageName: unknown
   linkType: soft
 
+"@babel/plugin-proposal-regexp-modifiers@workspace:^, @babel/plugin-proposal-regexp-modifiers@workspace:packages/babel-plugin-proposal-regexp-modifiers":
+  version: 0.0.0-use.local
+  resolution: "@babel/plugin-proposal-regexp-modifiers@workspace:packages/babel-plugin-proposal-regexp-modifiers"
+  dependencies:
+    "@babel/core": "workspace:^"
+    "@babel/helper-create-regexp-features-plugin": "workspace:^"
+    "@babel/helper-plugin-utils": "workspace:^"
+  peerDependencies:
+    "@babel/core": ^7.0.0
+  languageName: unknown
+  linkType: soft
+
 "@babel/plugin-proposal-throw-expressions@workspace:^, @babel/plugin-proposal-throw-expressions@workspace:packages/babel-plugin-proposal-throw-expressions":
   version: 0.0.0-use.local
   resolution: "@babel/plugin-proposal-throw-expressions@workspace:packages/babel-plugin-proposal-throw-expressions"
@@ -3683,6 +3695,7 @@ __metadata:
     "@babel/plugin-proposal-private-methods": "workspace:^"
     "@babel/plugin-proposal-private-property-in-object": "workspace:^"
     "@babel/plugin-proposal-record-and-tuple": "workspace:^"
+    "@babel/plugin-proposal-regexp-modifiers": "workspace:^"
     "@babel/plugin-proposal-throw-expressions": "workspace:^"
     "@babel/plugin-proposal-unicode-property-regex": "workspace:^"
     "@babel/plugin-proposal-unicode-sets-regex": "workspace:^"
@@ -13121,17 +13134,17 @@ fsevents@^1.2.7:
   languageName: node
   linkType: hard
 
-"regexpu-core@npm:^5.2.1":
-  version: 5.3.0
-  resolution: "regexpu-core@npm:5.3.0"
+"regexpu-core@npm:^5.2.1, regexpu-core@npm:^5.3.1":
+  version: 5.3.1
+  resolution: "regexpu-core@npm:5.3.1"
   dependencies:
     "@babel/regjsgen": ^0.8.0
     regenerate: ^1.4.2
     regenerate-unicode-properties: ^10.1.0
     regjsparser: ^0.9.1
     unicode-match-property-ecmascript: ^2.0.0
     unicode-match-property-value-ecmascript: ^2.1.0
-  checksum: f3c7921543ebda919c53fdbbf3a9cebbecbf8ad65b30e423d7eaef35484e08cbc919f9e8334f4693a72206f583d4f2b48d4415483f6e6e8c81f0046e3a23c66f
+  checksum: 446fbbb79059afcd64d11ea573276e2df97ee7ad45aa452834d3b2aef7edf7bfe206c310f57f9345d8c95bfedbf9c16a9529f9219a05ae6a6b0d6f0dbe523b33
   languageName: node
   linkType: hard