Function handler

packages/vite/src/node/plugins/workerImportMetaUrl.ts:208–291

(code, id)

    transform: {
      filter: { code: workerImportMetaUrlRE },
      async handler(code, id) {
        const isBundled = this.environment.config.isBundled
        let s: MagicString | undefined
        const cleanString = stripLiteral(code)
        const re = new RegExp(workerImportMetaUrlRE)

        let match: RegExpExecArray | null
        while ((match = re.exec(cleanString))) {
          const [[, endIndex], [expStart, expEnd], [urlStart, urlEnd]] =
            match.indices as Array<[number, number]>

          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') {
                builtUrl = toOutputFilePathInJSForBundledDev(
                  this.environment,
                  result.entryFilename,
                )
              } else {
                builtUrl = result.entryUrlPlaceholder