Method handleFilesystemEvents

packages/cli/src/util/dev/server.ts:320–423

(events: FSEvent[])

  }

  async handleFilesystemEvents(events: FSEvent[]): Promise<void> {
    output.debug(`Filesystem watcher notified of ${events.length} events`);

    const filesChanged: Set<string> = new Set();
    const filesRemoved: Set<string> = new Set();

    const distPaths: string[] = [];

    for (const buildMatch of this.buildMatches.values()) {
      for (const buildResult of buildMatch.buildResults.values()) {
        if (buildResult.distPath) {
          distPaths.push(buildResult.distPath);
        }
      }
    }

    events = events.filter(event =>
      distPaths.every(distPath => !event.path.startsWith(distPath))
    );

    // First, update the `files` mapping of source files
    for (const event of events) {
      if (event.type === 'add') {
        await this.handleFileCreated(event.path, filesChanged, filesRemoved);
      } else if (event.type === 'unlink') {
        this.handleFileDeleted(event.path, filesChanged, filesRemoved);
      } else if (event.type === 'change') {
        await this.handleFileModified(event.path, filesChanged, filesRemoved);
      }
    }

    const vercelConfig = await this.getVercelConfig();

    // Update the build matches in case an entrypoint was created or deleted
    await this.updateBuildMatches(vercelConfig);

    const filesChangedArray = [...filesChanged];
    const filesRemovedArray = [...filesRemoved];

    // Trigger rebuilds of any existing builds that are dependent
    // on one of the files that has changed
    const needsRebuild: Map<BuildResult, [string | null, BuildMatch]> =
      new Map();

    for (const match of this.buildMatches.values()) {
      for (const [requestPath, result] of match.buildResults) {
        // If the `BuildResult` is already queued for a re-build,
        // then we can skip subsequent lookups
        if (needsRebuild.has(result)) continue;

        if (Array.isArray(result.watch)) {
          for (const pattern of result.watch) {
            if (
              minimatches(filesChangedArray, pattern) ||
              minimatches(filesRemovedArray, pattern)
            ) {
              needsRebuild.set(result, [requestPath, match]);
              break;