Function startServer

snowpack/src/commands/dev.ts:257–1039

(
  commandOptions: CommandOptions,
  {
    isDev: _isDev,
    isWatch: _isWatch,
    preparePackages: _preparePackages,
  }: {isDev?: boolean; isWatch?: boolean; preparePackages?: boolean} = {},
)

}

export async function startServer(
  commandOptions: CommandOptions,
  {
    isDev: _isDev,
    isWatch: _isWatch,
    preparePackages: _preparePackages,
  }: {isDev?: boolean; isWatch?: boolean; preparePackages?: boolean} = {},
): Promise<SnowpackDevServer> {
  const {config} = commandOptions;
  const isDev = _isDev ?? config.mode !== 'production';
  const isWatch = _isWatch ?? true;
  const isPreparePackages = _preparePackages ?? true;
  const pkgSource = getPackageSource(config);
  if (isPreparePackages) {
    await pkgSource.prepare();
    logger.info(colors.bold('Ready!'));
  }
  let serverStart = performance.now();
  const {port: defaultPort, hostname, open, openUrl} = config.devOptions;
  const messageBus = new EventEmitter();
  const PACKAGE_PATH_PREFIX = path.posix.join(config.buildOptions.metaUrlPath, 'pkg/');
  const PACKAGE_LINK_PATH_PREFIX = path.posix.join(config.buildOptions.metaUrlPath, 'link/');
  let port: number | undefined;
  let warnedDeprecatedPackageImport = new Set();
  if (defaultPort !== 0) {
    port = await getPort(defaultPort);
    // Reset the clock if we had to wait for the user prompt to select a new port.
    if (port !== defaultPort) {
      serverStart = performance.now();
    }
  }

  // Fill in any command-specific plugin methods.
  for (const p of config.plugins) {
    p.markChanged = (fileLoc) => {
      knownETags.clear();
      onWatchEvent(fileLoc);
    };
  }

  if (isWatch && config.devOptions.output === 'dashboard' && process.stdout.isTTY) {
    startDashboard(messageBus, config);
  } else {
    // "stream": Log relevent events to the console.
    messageBus.on(paintEvent.WORKER_MSG, ({id, msg}) => {
      logger.info(msg.trim(), {name: id});
    });
  }

  const symlinkDirectories = new Map<string, Promise<any>>();
  const inMemoryBuildCache = new Map<string, FileBuilder>();
  let fileToUrlMapping = new OneToManyMap();
  const excludeGlobs = [
    ...config.exclude,
    ...(config.mode === 'test' ? [] : config.testOptions.files),
  ];

  const foundExcludeMatch = picomatch(excludeGlobs, {ignore: '**/node_modules/**'});