workerImportMetaUrlPlugin() — vite Function Reference

Source Code

packages/vite/src/node/plugins/workerImportMetaUrl.ts lines 186–297

export function workerImportMetaUrlPlugin(config: ResolvedConfig): Plugin {
  const isBundled = config.isBundled
  let workerResolver: ResolveIdFn

  const fsResolveOptions: InternalResolveOptions = {
    ...config.resolve,
    root: config.root,
    isProduction: config.isProduction,
    isBuild: config.command === 'build',
    packageCache: config.packageCache,
    asSrc: true,
  }

  return {
    name: 'vite:worker-import-meta-url',

    applyToEnvironment(environment) {
      return environment.config.consumer === 'client'
    },

    transform: {
      filter: { code: workerImportMetaUrlRE },
      async handler(code, id) {
        let s: MagicString | undefined
        const cleanString = stripLiteral(code)
        const workerImportMetaUrlRE =
          /\bnew\s+(?:Worker|SharedWorker)\s*\(\s*(new\s+URL\s*\(\s*('[^']+'|"[^"]+"|`[^`]+`)\s*,\s*import\.meta\.url\s*(?:,\s*)?\))/dg

        let match: RegExpExecArray | null
        while ((match = workerImportMetaUrlRE.exec(cleanString))) {
          const [[, endIndex], [expStart, expEnd], [urlStart, urlEnd]] =
            match.indices!

          const rawUrl = code.slice(urlStart, urlEnd)

          // potential dynamic template string
          if (rawUrl[0] === '`' && rawUrl.includes('${')) {
            this.error(
              `\`new URL(url, import.meta.url)\` is not supported in dynamic template string.`,
              expStart,
            )
          }

          s ||= new MagicString(code)
          const workerType = await getWorkerType(code, cleanString, endIndex)
          const url = rawUrl.slice(1, -1)
          let file: string | undefined
          if (url[0] === '.') {
            file = path.resolve(path.dirname(id), url)
            file = slash(tryFsResolve(file, fsResolveOptions) ?? file)
          } else {
            workerResolver ??= createBackCompatIdResolver(config, {
              extensions: [],
              tryIndex: false,
              preferRelative: true,
            })
            file = await workerResolver(this.environment, url, id)
            file ??=
              url[0] === '/'
                ? slash(path.join(config.publicDir, url))
                : slash(path.resolve(path.dirname(id), url))
          }

          if (
            isBundled &&
            config.isWorker &&
            config.bundleChain.at(-1) === cleanUrl(file)
          ) {
            s.update(expStart, expEnd, 'self.location.href')
          } else {
            let builtUrl: string
            if (isBundled) {
              const result = await workerFileToUrl(config, file)
              if (
                this.environment.config.command === 'serve' &&
                this.environment.config.experimental.bundledDev
              ) {
                builtUrl = toOutputFilePathInJSForBundledDev(
                  this.environment,
                  result.entryFilename,
                )