Function createPerformWatchHost

packages/compiler-cli/src/perform_watch.ts:61–116

(
  configFileName: string,
  reportDiagnostics: (diagnostics: ReadonlyArray<ts.Diagnostic>) => void,
  existingOptions?: ts.CompilerOptions,
  createEmitCallback?: (options: api.CompilerOptions) => api.TsEmitCallback<CbEmitRes> | undefined,
)

}

export function createPerformWatchHost<CbEmitRes extends ts.EmitResult = ts.EmitResult>(
  configFileName: string,
  reportDiagnostics: (diagnostics: ReadonlyArray<ts.Diagnostic>) => void,
  existingOptions?: ts.CompilerOptions,
  createEmitCallback?: (options: api.CompilerOptions) => api.TsEmitCallback<CbEmitRes> | undefined,
): PerformWatchHost {
  return {
    reportDiagnostics: reportDiagnostics,
    createCompilerHost: (options) => createCompilerHost({options}),
    readConfiguration: () => readConfiguration(configFileName, existingOptions),
    createEmitCallback: (options) => (createEmitCallback ? createEmitCallback(options) : undefined),
    onFileChange: (options, listener, ready: () => void) => {
      if (!options.basePath) {
        reportDiagnostics([
          {
            category: ts.DiagnosticCategory.Error,
            messageText: 'Invalid configuration option. baseDir not specified',
            source: api.SOURCE,
            code: api.DEFAULT_ERROR_CODE,
            file: undefined,
            start: undefined,
            length: undefined,
          },
        ]);
        return {close: () => {}};
      }
      const watcher = chokidar.watch(options.basePath, {
        // ignore .dotfiles, .js and .map files.
        // can't ignore other files as we e.g. want to recompile if an `.html` file changes as well.
        ignored: (path) =>
          /((^[\/\\])\..)|(\.js$)|(\.map$)|(\.metadata\.json|node_modules)/.test(path),
        ignoreInitial: true,
        persistent: true,
      });
      watcher.on('all', (event: string, path: string) => {
        switch (event) {
          case 'change':
            listener(FileChangeEvent.Change, path);
            break;
          case 'unlink':
          case 'add':
            listener(FileChangeEvent.CreateDelete, path);
            break;
          case 'unlinkDir':
          case 'addDir':
            listener(FileChangeEvent.CreateDeleteDir, path);
            break;
        }
      });
      watcher.on('ready', ready);
      return {close: () => watcher.close(), ready};
    },
    setTimeout: (ts.sys.clearTimeout && ts.sys.setTimeout) || setTimeout,
    clearTimeout: (ts.sys.setTimeout && ts.sys.clearTimeout) || clearTimeout,
  };
}

interface CacheEntry {