Function readAndWatchFileWithHash

tools/fs/watch.ts:845–882

(watchSet: WatchSet, absPath: string)

// *rely* on the hash being returned; merely that if the hash is
// present, it is the correct hash of the contents.
export function readAndWatchFileWithHash(watchSet: WatchSet, absPath: string) {
  const result: {
    contents: string | Buffer | null;
    hash: string | null;
  } = {
    contents: null,
    hash: null,
  };

  try {
    result.contents = files.readFile(absPath);
  } catch (e) {
    if (e && e.code === "EISDIR") {
      // Avoid adding directories to the watchSet as files.
      return result;
    }

    if (e && e.code === "ENOENT") {
      // Continue, leaving result.{contents,hash} both null.
    } else {
      // Throw all other errors.
      throw e;
    }
  }

  if (result.contents !== null) {
    result.hash = sha1(result.contents);
  }

  // Allow null watchSet, if we want to use readFile-style error handling in a
  // context where we might not always have a WatchSet (eg, reading
  // settings.json where we watch for "meteor run" but not for "meteor deploy").
  if (watchSet) {
    watchSet.addFile(absPath, result.hash);
  }

  return result;
}

export function readAndWatchFile(watchSet: WatchSet, absPath: string) {
  return readAndWatchFileWithHash(watchSet, absPath).contents;