Future update()

in frontend_server_common/lib/src/devfs.dart [63:141]
71 lines of code
5 McCabe index (conditional complexity)

  Future<UpdateFSReport> update({
    String mainPath,
    AssetBundle bundle,
    String dillOutputPath,
    @required ResidentCompiler generator,
    List<Uri> invalidatedFiles,
  }) async {
    assert(generator != null);
    var outputDirectoryPath = fileSystem.file(mainPath).parent.path;
    var entryPoint = mainPath;

    assetServer.writeFile(
      '/main.dart.js',
      generateBootstrapScript(
        requireUrl: _filePathToUriFragment(requireJS.path),
        mapperUrl: _filePathToUriFragment(stackTraceMapper.path),
        entrypoint: entryPoint,
      ),
    );
    assetServer.writeFile(
      '/main_module.bootstrap.js',
      generateMainModule(
        entrypoint: entryPoint,
      ),
    );

    assetServer.writeFile('/main_module.digests', '{}');
    assetServer.writeFile('/dart_sdk.js', dartSdk.readAsStringSync());
    assetServer.writeFile(
        '/dart_sdk.js.map', dartSdkSourcemap.readAsStringSync());
    // TODO(jonahwilliams): refactor the asset code in this and the regular devfs to
    // be shared.
    if (bundle != null) {
      await writeBundle(
        fileSystem.directory(p.joinAll(['build', 'assets'])),
        bundle.entries,
      );
    }

    generator.reset();

    var compilerOutput = await generator.recompile(
      'org-dartlang-app:///$mainPath',
      invalidatedFiles,
      outputPath: p.join(dillOutputPath, 'app.dill'),
      packagesFilePath: packagesFilePath,
    );
    if (compilerOutput == null || compilerOutput.errorCount > 0) {
      return UpdateFSReport(success: false);
    }

    // list of sources that needs to be monitored are in [compilerOutput.sources]
    sources = compilerOutput.sources;
    File codeFile;
    File manifestFile;
    File sourcemapFile;
    File metadataFile;
    List<String> modules;
    try {
      var parentDirectory = fileSystem.directory(outputDirectoryPath);
      codeFile =
          parentDirectory.childFile('${compilerOutput.outputFilename}.sources');
      manifestFile =
          parentDirectory.childFile('${compilerOutput.outputFilename}.json');
      sourcemapFile =
          parentDirectory.childFile('${compilerOutput.outputFilename}.map');
      metadataFile = parentDirectory
          .childFile('${compilerOutput.outputFilename}.metadata');
      modules = assetServer.write(
          codeFile, manifestFile, sourcemapFile, metadataFile);
    } on FileSystemException catch (err) {
      throw Exception('Failed to load recompiled sources:\n$err');
    }
    return UpdateFSReport(
      success: true,
      syncedBytes: codeFile.lengthSync(),
      invalidatedSourcesCount: invalidatedFiles.length,
    )..invalidatedModules = modules;
  }