perf: regexp perf issues, refactor regexp stylistic issues

.eslintrc.cjs

@@ -7,9 +7,10 @@ module.exports = defineConfig({
   extends: [
     'eslint:recommended',
     'plugin:node/recommended',
-    'plugin:@typescript-eslint/recommended'
+    'plugin:@typescript-eslint/recommended',
+    'plugin:regexp/recommended'
   ],
-  plugins: ['import'],
+  plugins: ['import', 'regexp'],
   parser: '@typescript-eslint/parser',
   parserOptions: {
     sourceType: 'module',
@@ -97,7 +98,9 @@ module.exports = defineConfig({
         memberSyntaxSortOrder: ['none', 'all', 'multiple', 'single'],
         allowSeparatedGroups: false
       }
-    ]
+    ],
+
+    'regexp/no-contradiction-with-assertion': 'error'
   },
   overrides: [
     {

package.json

@@ -66,6 +66,7 @@
     "eslint-define-config": "^1.11.0",
     "eslint-plugin-import": "^2.26.0",
     "eslint-plugin-node": "^11.1.0",
+    "eslint-plugin-regexp": "^1.10.0",
     "execa": "^6.1.0",
     "fast-glob": "^3.2.12",
     "fs-extra": "^10.1.0",

packages/create-vite/src/index.ts

@@ -388,7 +388,7 @@ function copy(src: string, dest: string) {
 }
 
 function isValidPackageName(projectName: string) {
-  return /^(?:@[a-z0-9-*~][a-z0-9-*._~]*\/)?[a-z0-9-~][a-z0-9-._~]*$/.test(
+  return /^(?:@[a-z\d\-*~][a-z\d\-*._~]*\/)?[a-z\d\-~][a-z\d\-._~]*$/.test(
     projectName
   )
 }
@@ -399,7 +399,7 @@ function toValidPackageName(projectName: string) {
     .toLowerCase()
     .replace(/\s+/g, '-')
     .replace(/^[._]/, '')
-    .replace(/[^a-z0-9-~]+/g, '-')
+    .replace(/[^a-z\d\-~]+/g, '-')
 }
 
 function copyDir(srcDir: string, destDir: string) {

packages/plugin-react/src/fast-refresh.ts

@@ -56,7 +56,7 @@ if (import.meta.hot) {
     RefreshRuntime.register(type, __SOURCE__ + " " + id)
   };
   window.$RefreshSig$ = RefreshRuntime.createSignatureFunctionForTransform;
-}`.replace(/[\n]+/gm, '')
+}`.replace(/\n+/g, '')
 
 const timeout = `
   if (!window.__vite_plugin_react_timeout) {

packages/plugin-react/src/index.ts

@@ -110,10 +110,10 @@ export default function viteReact(opts: Options = {}): PluginOption[] {
   // - import * as React from 'react';
   // - import React from 'react';
   // - import React, {useEffect} from 'react';
-  const importReactRE = /(^|\n)import\s+(\*\s+as\s+)?React(,|\s+)/
+  const importReactRE = /(?:^|\n)import\s+(?:\*\s+as\s+)?React(?:,|\s+)/
 
   // Any extension, including compound ones like '.bs.js'
-  const fileExtensionRE = /\.[^\/\s\?]+$/
+  const fileExtensionRE = /\.[^/\s?]+$/
 
   const viteBabel: Plugin = {
     name: 'vite:react-babel',
@@ -202,7 +202,7 @@ export default function viteReact(opts: Options = {}): PluginOption[] {
         filepath.match(fileExtensionRE) ||
         []
 
-      if (/\.(mjs|[tj]sx?)$/.test(extension)) {
+      if (/\.(?:mjs|[tj]sx?)$/.test(extension)) {
         const isJSX = extension.endsWith('x')
         const isNodeModules = id.includes('/node_modules/')
         const isProjectFile =

packages/plugin-vue/src/handleHotUpdate.ts

@@ -11,7 +11,7 @@ import type { ResolvedOptions } from '.'
 
 const debug = _debug('vite:hmr')
 
-const directRequestRE = /(\?|&)direct\b/
+const directRequestRE = /(?:\?|&)direct\b/
 
 /**
  * Vite-specific HMR handling
@@ -148,7 +148,7 @@ export async function handleHotUpdate(
       affectedModules.add(mainModule)
     } else if (mainModule && !affectedModules.has(mainModule)) {
       const styleImporters = [...mainModule.importers].filter((m) =>
-        /\.css($|\?)/.test(m.url)
+        /\.css(?:$|\?)/.test(m.url)
       )
       styleImporters.forEach((m) => affectedModules.add(m))
     }

packages/vite/src/node/config.ts

@@ -465,8 +465,8 @@ export async function resolveConfig(
   )
 
   const clientAlias = [
-    { find: /^[\/]?@vite\/env/, replacement: () => ENV_ENTRY },
-    { find: /^[\/]?@vite\/client/, replacement: () => CLIENT_ENTRY }
+    { find: /^\/?@vite\/env/, replacement: () => ENV_ENTRY },
+    { find: /^\/?@vite\/client/, replacement: () => CLIENT_ENTRY }
   ]
 
   // resolve alias with internal client alias

packages/vite/src/node/constants.ts

@@ -46,9 +46,9 @@ export const DEFAULT_CONFIG_FILES = [
 
 export const JS_TYPES_RE = /\.(?:j|t)sx?$|\.mjs$/
 
-export const OPTIMIZABLE_ENTRY_RE = /\.(?:[cm]?[jt]s)$/
+export const OPTIMIZABLE_ENTRY_RE = /\.[cm]?[jt]s$/
 
-export const SPECIAL_QUERY_RE = /[\?&](?:worker|sharedworker|raw|url)\b/
+export const SPECIAL_QUERY_RE = /[?&](?:worker|sharedworker|raw|url)\b/
 
 /**
  * Prefix for resolved fs paths, since windows paths may not be valid as URLs.
@@ -129,7 +129,7 @@ export const DEFAULT_ASSETS_RE = new RegExp(
   `\\.(` + KNOWN_ASSET_TYPES.join('|') + `)(\\?.*)?$`
 )
 
-export const DEP_VERSION_RE = /[\?&](v=[\w\.-]+)\b/
+export const DEP_VERSION_RE = /[?&](v=[\w.-]+)\b/
 
 export const loopbackHosts = new Set([
   'localhost',

packages/vite/src/node/optimizer/esbuildDepPlugin.ts

@@ -265,7 +265,7 @@ export function esbuildCjsExternalPlugin(externals: string[]): Plugin {
     name: 'cjs-external',
     setup(build) {
       const escape = (text: string) =>
-        `^${text.replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&')}$`
+        `^${text.replace(/[-/\\^$*+?.()|[\]{}]/g, '\\$&')}$`
       const filter = new RegExp(externals.map(escape).join('|'))
 
       build.onResolve({ filter: /.*/, namespace: 'external' }, (args) => ({

packages/vite/src/node/optimizer/scan.ts

@@ -40,7 +40,7 @@ const htmlTypesRE = /\.(html|vue|svelte|astro|imba)$/
 // since even missed imports can be caught at runtime, and false positives will
 // simply be ignored.
 export const importsRE =
-  /(?<!\/\/.*)(?<=^|;|\*\/)\s*import(?!\s+type)(?:[\w*{}\n\r\t, ]+from\s*)?\s*("[^"]+"|'[^']+')\s*(?=$|;|\/\/|\/\*)/gm
+  /(?<!\/\/.*)(?<=^|;|\*\/)\s*import(?!\s+type)(?:[\w*{}\n\r\t, ]+from)?\s*("[^"]+"|'[^']+')\s*(?=$|;|\/\/|\/\*)/gm
 
 export async function scanImports(config: ResolvedConfig): Promise<{
   deps: Record<string, string>
@@ -149,13 +149,13 @@ function globEntries(pattern: string | string[], config: ResolvedConfig) {
 }
 
 const scriptModuleRE =
-  /(<script\b[^>]*type\s*=\s*(?:"module"|'module')[^>]*>)(.*?)<\/script>/gims
-export const scriptRE = /(<script\b(?:\s[^>]*>|>))(.*?)<\/script>/gims
+  /(<script\b[^>]+type\s*=\s*(?:"module"|'module')[^>]*>)(.*?)<\/script>/gis
+export const scriptRE = /(<script(?:\s[^>]*>|>))(.*?)<\/script>/gis
 export const commentRE = /<!--.*?-->/gs
-const srcRE = /\bsrc\s*=\s*(?:"([^"]+)"|'([^']+)'|([^\s'">]+))/im
-const typeRE = /\btype\s*=\s*(?:"([^"]+)"|'([^']+)'|([^\s'">]+))/im
-const langRE = /\blang\s*=\s*(?:"([^"]+)"|'([^']+)'|([^\s'">]+))/im
-const contextRE = /\bcontext\s*=\s*(?:"([^"]+)"|'([^']+)'|([^\s'">]+))/im
+const srcRE = /\bsrc\s*=\s*(?:"([^"]+)"|'([^']+)'|([^\s'">]+))/i
+const typeRE = /\btype\s*=\s*(?:"([^"]+)"|'([^']+)'|([^\s'">]+))/i
+const langRE = /\blang\s*=\s*(?:"([^"]+)"|'([^']+)'|([^\s'">]+))/i
+const contextRE = /\bcontext\s*=\s*(?:"([^"]+)"|'([^']+)'|([^\s'">]+))/i
 
 function esbuildScanPlugin(
   config: ResolvedConfig,

packages/vite/src/node/plugins/asset.ts

@@ -29,7 +29,7 @@ export const duplicateAssets = new WeakMap<
   Map<string, OutputAsset>
 >()
 
-const rawRE = /(\?|&)raw(?:&|$)/
+const rawRE = /(?:\?|&)raw(?:&|$)/
 const urlRE = /(\?|&)url(?:&|$)/
 
 const assetCache = new WeakMap<ResolvedConfig, Map<string, string>>()
@@ -173,7 +173,7 @@ export function assetPlugin(config: ResolvedConfig): Plugin {
         return
       }
 
-      id = id.replace(urlRE, '$1').replace(/[\?&]$/, '')
+      id = id.replace(urlRE, '$1').replace(/[?&]$/, '')
       const url = await fileToUrl(id, config, this)
       return `export default ${JSON.stringify(url)}`
     },

packages/vite/src/node/plugins/assetImportMetaUrl.ts

@@ -38,7 +38,7 @@ export function assetImportMetaUrlPlugin(config: ResolvedConfig): Plugin {
       ) {
         let s: MagicString | undefined
         const assetImportMetaUrlRE =
-          /\bnew\s+URL\s*\(\s*('[^']+'|"[^"]+"|`[^`]+`)\s*,\s*import\.meta\.url\s*,?\s*\)/g
+          /\bnew\s+URL\s*\(\s*('[^']+'|"[^"]+"|`[^`]+`)\s*,\s*import\.meta\.url\s*(?:,\s*)?\)/g
         const cleanString = stripLiteral(code)
 
         let match: RegExpExecArray | null

packages/vite/src/node/plugins/css.ts

@@ -111,13 +111,14 @@ export interface CSSModulesOptions {
 
 const cssLangs = `\\.(css|less|sass|scss|styl|stylus|pcss|postcss|sss)($|\\?)`
 const cssLangRE = new RegExp(cssLangs)
+// eslint-disable-next-line regexp/no-unused-capturing-group
 const cssModuleRE = new RegExp(`\\.module${cssLangs}`)
-const directRequestRE = /(\?|&)direct\b/
-const htmlProxyRE = /(\?|&)html-proxy\b/
+const directRequestRE = /(?:\?|&)direct\b/
+const htmlProxyRE = /(?:\?|&)html-proxy\b/
 const commonjsProxyRE = /\?commonjs-proxy/
-const inlineRE = /(\?|&)inline\b/
-const inlineCSSRE = /(\?|&)inline-css\b/
-const usedRE = /(\?|&)used\b/
+const inlineRE = /(?:\?|&)inline\b/
+const inlineCSSRE = /(?:\?|&)inline-css\b/
+const usedRE = /(?:\?|&)used\b/
 const varRE = /^var\(/i
 
 const cssBundleName = 'style.css'
@@ -1175,11 +1176,13 @@ type CssUrlReplacer = (
 ) => string | Promise<string>
 // https://drafts.csswg.org/css-syntax-3/#identifier-code-point
 export const cssUrlRE =
-  /(?<=^|[^\w\-\u0080-\uffff])url\(\s*('[^']+'|"[^"]+"|[^'")]+)\s*\)/
+  /(?<=^|[^\w\-\u0080-\uffff])url\((\s*('[^']+'|"[^"]+")\s*|[^'")]+)\)/
 export const cssDataUriRE =
-  /(?<=^|[^\w\-\u0080-\uffff])data-uri\(\s*('[^']+'|"[^"]+"|[^'")]+)\s*\)/
+  /(?<=^|[^\w\-\u0080-\uffff])data-uri\((\s*('[^']+'|"[^"]+")\s*|[^'")]+)\)/
 export const importCssRE = /@import ('[^']+\.css'|"[^"]+\.css"|[^'")]+\.css)/
-const cssImageSetRE = /(?<=image-set\()((?:[\w\-]+\([^\)]*\)|[^)])*)(?=\))/
+// Assuming a function name won't be longer than 256 chars
+// eslint-disable-next-line regexp/no-unused-capturing-group -- doesn't detect asyncReplace usage
+const cssImageSetRE = /(?<=image-set\()((?:[\w\-]{1,256}\([^)]*\)|[^)])*)(?=\))/
 
 const UrlRewritePostcssPlugin: PostCSS.PluginCreator<{
   replacer: CssUrlReplacer
@@ -1235,7 +1238,7 @@ function rewriteCssUrls(
 ): Promise<string> {
   return asyncReplace(css, cssUrlRE, async (match) => {
     const [matched, rawUrl] = match
-    return await doUrlReplace(rawUrl, matched, replacer)
+    return await doUrlReplace(rawUrl.trim(), matched, replacer)
   })
 }
 
@@ -1245,7 +1248,7 @@ function rewriteCssDataUris(
 ): Promise<string> {
   return asyncReplace(css, cssDataUriRE, async (match) => {
     const [matched, rawUrl] = match
-    return await doUrlReplace(rawUrl, matched, replacer, 'data-uri')
+    return await doUrlReplace(rawUrl.trim(), matched, replacer, 'data-uri')
   })
 }
 
@@ -1262,7 +1265,7 @@ function rewriteImportCss(
 // TODO: image and cross-fade could contain a "url" that needs to be processed
 // https://drafts.csswg.org/css-images-4/#image-notation
 // https://drafts.csswg.org/css-images-4/#cross-fade-function
-const cssNotProcessedRE = /(gradient|element|cross-fade|image)\(/
+const cssNotProcessedRE = /(?:gradient|element|cross-fade|image)\(/
 
 async function rewriteCssImageSet(
   css: string,
@@ -1391,7 +1394,7 @@ export async function hoistAtRules(css: string): Promise<string> {
   // to top when multiple files are concatenated.
   // match until semicolon that's not in quotes
   const atImportRE =
-    /@import\s*(?:url\([^\)]*\)|"([^"]|(?<=\\)")*"|'([^']|(?<=\\)')*'|[^;]*).*?;/gm
+    /@import(?:\s*(?:url\([^)]*\)|"(?:[^"]|(?<=\\)")*"|'(?:[^']|(?<=\\)')*').*?|[^;]*);/g
   while ((match = atImportRE.exec(cleanCss))) {
     s.remove(match.index, match.index + match[0].length)
     // Use `appendLeft` instead of `prepend` to preserve original @import order
@@ -1401,7 +1404,7 @@ export async function hoistAtRules(css: string): Promise<string> {
   // #6333
   // CSS @charset must be the top-first in the file, hoist the first to top
   const atCharsetRE =
-    /@charset\s*(?:"([^"]|(?<=\\)")*"|'([^']|(?<=\\)')*'|[^;]*).*?;/gm
+    /@charset(?:\s*(?:"(?:[^"]|(?<=\\)")*"|'(?:[^']|(?<=\\)')*').*?|[^;]*);/g
   let foundCharset = false
   while ((match = atCharsetRE.exec(cleanCss))) {
     s.remove(match.index, match.index + match[0].length)

packages/vite/src/node/plugins/define.ts

@@ -5,7 +5,7 @@ import { transformStableResult } from '../utils'
 import { isCSSRequest } from './css'
 import { isHTMLRequest } from './html'
 
-const nonJsRe = /\.(json)($|\?)/
+const nonJsRe = /\.json(?:$|\?)/
 const isNonJsRequest = (request: string): boolean => nonJsRe.test(request)
 
 export function definePlugin(config: ResolvedConfig): Plugin {

packages/vite/src/node/plugins/esbuild.ts

@@ -27,9 +27,9 @@ import { searchForWorkspaceRoot } from '..'
 const debug = createDebugger('vite:esbuild')
 
 const INJECT_HELPERS_IIFE_RE =
-  /^(.*)((?:const|var) [^\s]+=function\([^)]*?\){"use strict";)/s
+  /^(.*?)((?:const|var) \S+=function\([^)]*\)\{"use strict";)/s
 const INJECT_HELPERS_UMD_RE =
-  /^(.*)(\(function\([^)]*?\){.+amd.+function\([^)]*?\){"use strict";)/s
+  /^(.*?)(\(function\([^)]*\)\{.+amd.+function\([^)]*\)\{"use strict";)/s
 
 let server: ViteDevServer
 

packages/vite/src/node/plugins/html.ts

@@ -44,12 +44,13 @@ const htmlProxyRE = /\?html-proxy=?(?:&inline-css)?&index=(\d+)\.(js|css)$/
 const inlineCSSRE = /__VITE_INLINE_CSS__([a-z\d]{8}_\d+)__/g
 // Do not allow preceding '.', but do allow preceding '...' for spread operations
 const inlineImportRE =
-  /(?<!(?<!\.\.)\.)\bimport\s*\(("([^"]|(?<=\\)")*"|'([^']|(?<=\\)')*')\)/g
-const htmlLangRE = /\.(html|htm)$/
+  /(?<!(?<!\.\.)\.)\bimport\s*\(("(?:[^"]|(?<=\\)")*"|'(?:[^']|(?<=\\)')*')\)/g
+const htmlLangRE = /\.(?:html|htm)$/
 
 const importMapRE =
-  /[ \t]*<script[^>]*type\s*=\s*["']?importmap["']?[^>]*>.*?<\/script>/is
-const moduleScriptRE = /[ \t]*<script[^>]*type\s*=\s*["']?module["']?[^>]*>/is
+  /[ \t]*<script[^>]*type\s*=\s*(?:"importmap"|'importmap'|importmap)[^>]*>.*?<\/script>/is
+const moduleScriptRE =
+  /[ \t]*<script[^>]*type\s*=\s*(?:"module"|'module'|module)[^>]*>/i
 
 export const isHTMLProxy = (id: string): boolean => htmlProxyRE.test(id)
 
@@ -197,7 +198,7 @@ export function getScriptInfo(node: DefaultTreeAdapterMap['element']): {
   return { src, sourceCodeLocation, isModule, isAsync }
 }
 
-const attrValueStartRE = /=[\s\t\n\r]*(.)/
+const attrValueStartRE = /=\s*(.)/
 
 export function overwriteAttrValue(
   s: MagicString,

packages/vite/src/node/plugins/importAnalysis.ts

@@ -71,12 +71,12 @@ const debug = createDebugger('vite:import-analysis')
 
 const clientDir = normalizePath(CLIENT_DIR)
 
-const skipRE = /\.(map|json)($|\?)/
+const skipRE = /\.(?:map|json)(?:$|\?)/
 export const canSkipImportAnalysis = (id: string): boolean =>
   skipRE.test(id) || isDirectCSSRequest(id)
 
-const optimizedDepChunkRE = /\/chunk-[A-Z0-9]{8}\.js/
-const optimizedDepDynamicRE = /-[A-Z0-9]{8}\.js/
+const optimizedDepChunkRE = /\/chunk-[A-Z\d]{8}\.js/
+const optimizedDepDynamicRE = /-[A-Z\d]{8}\.js/
 
 export function isExplicitImportRequired(url: string): boolean {
   return !isJSRequest(cleanUrl(url)) && !isCSSRequest(url)
@@ -347,7 +347,7 @@ export function importAnalysisPlugin(config: ResolvedConfig): Plugin {
           // query can break 3rd party plugin's extension checks.
           if (
             (isRelative || isSelfImport) &&
-            !/[\?&]import=?\b/.test(url) &&
+            !/[?&]import=?\b/.test(url) &&
             !url.match(DEP_VERSION_RE)
           ) {
             const versionMatch = importer.match(DEP_VERSION_RE)
@@ -583,7 +583,7 @@ export function importAnalysisPlugin(config: ResolvedConfig): Plugin {
               .replace(/\/\*[\s\S]*?\*\/|([^\\:]|^)\/\/.*$/gm, '')
               .trim()
             if (
-              !/^('.*'|".*"|`.*`)$/.test(url) ||
+              !/^(?:'.*'|".*"|`.*`)$/.test(url) ||
               isExplicitImportRequired(url.slice(1, -1))
             ) {
               needQueryInjectHelper = true

packages/vite/src/node/plugins/importAnalysisBuild.ts

@@ -38,8 +38,8 @@ const preloadMarkerWithQuote = `"${preloadMarker}"` as const
 const dynamicImportPrefixRE = /import\s*\(/
 
 // TODO: abstract
-const optimizedDepChunkRE = /\/chunk-[A-Z0-9]{8}\.js/
-const optimizedDepDynamicRE = /-[A-Z0-9]{8}\.js/
+const optimizedDepChunkRE = /\/chunk-[A-Z\d]{8}\.js/
+const optimizedDepDynamicRE = /-[A-Z\d]{8}\.js/
 
 function toRelativePath(filename: string, importer: string) {
   const relPath = path.relative(path.dirname(importer), filename)

packages/vite/src/node/plugins/json.ts

@@ -26,9 +26,9 @@ export interface JsonOptions {
 }
 
 // Custom json filter for vite
-const jsonExtRE = /\.json($|\?)(?!commonjs-(proxy|external))/
+const jsonExtRE = /\.json(?:$|\?)(?!commonjs-(?:proxy|external))/
 
-const jsonLangs = `\\.(json|json5)($|\\?)`
+const jsonLangs = `\\.(?:json|json5)(?:$|\\?)`
 const jsonLangRE = new RegExp(jsonLangs)
 export const isJSONRequest = (request: string): boolean =>
   jsonLangRE.test(request)
@@ -71,7 +71,7 @@ export function jsonPlugin(
           map: { mappings: '' }
         }
       } catch (e) {
-        const errorMessageList = /[\d]+/.exec(e.message)
+        const errorMessageList = /\d+/.exec(e.message)
         const position = errorMessageList && parseInt(errorMessageList[0], 10)
         const msg = position
           ? `, invalid JSON syntax found at line ${position}`