Add regex eslint plugin, fix lints (#59371)

Author: jakebailey

eslint.config.mjs

@@ -1,5 +1,6 @@
 // @ts-check
 import eslint from "@eslint/js";
+import * as regexpPlugin from "eslint-plugin-regexp";
 import fs from "fs";
 import globals from "globals";
 import { createRequire } from "module";
@@ -36,6 +37,7 @@ export default tseslint.config(
     eslint.configs.recommended,
     ...tseslint.configs.recommended,
     ...tseslint.configs.stylistic,
+    regexpPlugin.configs["flat/recommended"],
     {
         plugins: {
             local: {
@@ -208,6 +210,7 @@ export default tseslint.config(
         files: ["src/harness/**", "src/testRunner/**"],
         rules: {
             "no-restricted-globals": "off",
+            "regexp/no-super-linear-backtracking": "off",
             "local/no-direct-import": "off",
         },
     },

package-lock.json

@@ -64,6 +64,7 @@
         "esbuild": "^0.23.0",
         "eslint": "^9.9.0",
         "eslint-formatter-autolinkable-stylish": "^1.4.0",
+        "eslint-plugin-regexp": "^2.6.0",
         "fast-xml-parser": "^4.4.1",
         "glob": "^10.4.5",
         "globals": "^15.9.0",

package.json

@@ -105,7 +105,7 @@ export async function runConsoleTests(runJs, defaultReporter, runInParallel, opt
         }
         if (failed) {
             const grep = fs.readFileSync(".failed-tests", "utf8")
-                .split(/\r?\n/g)
+                .split(/\r?\n/)
                 .map(test => test.trim())
                 .filter(test => test.length > 0)
                 .map(regExpEscape)

scripts/build/tests.mjs

@@ -112,7 +112,7 @@ function getPrereleasePatch(tag, plainPatch) {
     // but we'd prefer to just remove separators and limit ourselves to YYYYMMDD.
     // UTC time will always be implicit here.
     const now = new Date();
-    const timeStr = now.toISOString().replace(/:|T|\.|-/g, "").slice(0, 8);
+    const timeStr = now.toISOString().replace(/[:T.-]/g, "").slice(0, 8);
 
     return `${plainPatch}-${tag}.${timeStr}`;
 }

scripts/configurePrerelease.mjs

@@ -124,7 +124,7 @@ class FailedTestsReporter extends Mocha.reporters.Base {
 
         function readTests() {
             return fs.readFileSync(file, "utf8")
-                .split(/\r?\n/g)
+                .split(/\r?\n/)
                 .map(line => line.trim())
                 .filter(line => line.length > 0);
         }

scripts/failed-tests.cjs

@@ -113,7 +113,7 @@ async function main() {
                 ItemId = ItemId.slice(1); // remove leading semicolon
             }
 
-            val = val.replace(/]5D;/, "]"); // unescape `]`
+            val = val.replace(/\]5D;/, "]"); // unescape `]`
             out[ItemId] = val;
         }
         return JSON.stringify(out, undefined, 2);
@@ -146,7 +146,7 @@ async function main() {
          */
         function getItemXML(key, value) {
             // escape entrt value
-            value = value.replace(/]/g, "]5D;");
+            value = value.replace(/\]/g, "]5D;");
 
             return `
             <Item ItemId=";${key}" ItemType="0" PsrId="306" Leaf="true">

scripts/generateLocalizedDiagnosticMessages.mjs

@@ -150,7 +150,7 @@ function convertPropertyName(origName) {
     result = result.replace(/_+/g, "_");
 
     // remove any leading underscore, unless it is followed by a number.
-    result = result.replace(/^_([^\d])/, "$1");
+    result = result.replace(/^_(\D)/, "$1");
 
     // get rid of all trailing underscores.
     result = result.replace(/_$/, "");

scripts/processDiagnosticMessages.mjs

@@ -1,8 +1,8 @@
 const MAX_UNICODE_CODEPOINT = 0x10FFFF;
 /** @type {(c: string) => boolean} */
-const isStart = c => /[\p{ID_Start}\u{2118}\u{212E}\u{309B}\u{309C}]/u.test(c); // Other_ID_Start explicitly included for back compat - see http://www.unicode.org/reports/tr31/#Introduction
+const isStart = c => /\p{ID_Start}/u.test(c); // Other_ID_Start explicitly included for back compat - see http://www.unicode.org/reports/tr31/#Introduction
 /** @type {(c: string) => boolean} */
-const isPart = c => /[\p{ID_Continue}\u{00B7}\u{0387}\u{19DA}\u{1369}\u{136A}\u{136B}\u{136C}\u{136D}\u{136E}\u{136F}\u{1370}\u{1371}]/u.test(c) || isStart(c); // Likewise for Other_ID_Continue
+const isPart = c => /\p{ID_Continue}/u.test(c) || isStart(c); // Likewise for Other_ID_Continue
 const parts = [];
 let partsActive = false;
 let startsActive = false;

scripts/regenerate-unicode-identifier-parts.mjs

@@ -10678,7 +10678,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 else if (localName === InternalSymbolName.ExportEquals) {
                     localName = "_exports";
                 }
-                localName = isIdentifierText(localName, languageVersion) && !isStringANonContextualKeyword(localName) ? localName : "_" + localName.replace(/[^a-zA-Z0-9]/g, "_");
+                localName = isIdentifierText(localName, languageVersion) && !isStringANonContextualKeyword(localName) ? localName : "_" + localName.replace(/[^a-z0-9]/gi, "_");
                 return localName;
             }
 
@@ -34355,7 +34355,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
 
     function containerSeemsToBeEmptyDomElement(containingType: Type) {
         return (compilerOptions.lib && !compilerOptions.lib.includes("dom")) &&
-            everyContainedType(containingType, type => type.symbol && /^(EventTarget|Node|((HTML[a-zA-Z]*)?Element))$/.test(unescapeLeadingUnderscores(type.symbol.escapedName))) &&
+            everyContainedType(containingType, type => type.symbol && /^(?:EventTarget|Node|(?:HTML[a-zA-Z]*)?Element)$/.test(unescapeLeadingUnderscores(type.symbol.escapedName))) &&
             isEmptyObjectType(containingType);
     }