Function build

build-system/tasks/helpers.js:326–418

* @param {number} startTime * @return {Promise }

(startTime)

   * @return {Promise<void>}
   */
  async function build(startTime) {
    if (!esbuildContext) {
      esbuildContext = await esbuild.context({
        entryPoints: [entryPoint],
        bundle: true,
        sourcemap: 'external',
        sourcesContent: includeSourcesContent(),
        outfile: destFile,
        define: experimentDefines,
        plugins,
        // When using `nomodule-loader` we build as ESM in order to preserve
        // import statements. These are transformed in a post-build Babel step.
        format:
          options.outputFormat === 'nomodule-loader'
            ? 'esm'
            : options.outputFormat,
        banner,
        footer,
        // For es5 builds, ensure esbuild-injected code is transpiled.
        target: argv.esm ? 'es6' : 'es5',
        logLevel: 'silent',
        external: options.externalDependencies,
        mainFields: ['module', 'browser', 'main'],
        write: false,
      });
    }

    const {outputFiles} = await esbuildContext.rebuild();
    if (outputFiles === undefined) {
      throw new Error(`No output files for ${destFilename}`);
    }

    const codeFile = outputFiles.find(({path}) => !path.endsWith('.map'));
    const mapFile = outputFiles.find(({path}) => path.endsWith('.map'));

    if (!codeFile || !mapFile) {
      throw new Error(
        `Expected code and map file for ${destFilename}; got ${outputFiles.map(
          ({path}) => path
        )}`
      );
    }

    let {text: code} = codeFile;
    const mapChain = [JSON.parse(mapFile.text)];

    if (options.outputFormat === 'nomodule-loader') {
      const result = await babel.transformAsync(code, {
        caller: {name: 'nomodule-loader'},
        filename: destFile,
        sourceRoot: path.dirname(destFile),
        sourceMaps: true,
      });
      if (!result?.code) {
        throw new Error('failed to babel');
      }
      code = result.code;
      mapChain.unshift(result.map);