Function rebasePr

ng-dev/pr/rebase/index.ts:22–169

(prNumber: number, interactive: boolean = false)

 * @returns a status code indicating whether the rebase was successful.
 */
export async function rebasePr(prNumber: number, interactive: boolean = false): Promise<number> {
  /** The singleton instance of the authenticated git client. */
  const git = await AuthenticatedGitClient.get();

  if (git.hasUncommittedChanges()) {
    Log.error('Cannot perform rebase of PR with local changes.');
    return 1;
  }

  /**
   * The branch or revision originally checked out before this method performed
   * any Git operations that may change the working branch.
   */
  const previousBranchOrRevision = git.getCurrentBranchOrRevision();
  /* Get the PR information from Github. */
  const pr = await fetchPullRequestFromGithub(git, prNumber);

  if (pr === null) {
    Log.error(`Specified pull request does not exist.`);
    return 1;
  }

  const headRefName = pr.headRef.name;
  const baseRefName = pr.baseRef.name;
  const fullHeadRef = `${pr.headRef.repository.nameWithOwner}:${headRefName}`;
  const fullBaseRef = `${pr.baseRef.repository.nameWithOwner}:${baseRefName}`;
  const headRefUrl = addTokenToGitHttpsUrl(pr.headRef.repository.url, git.githubToken);
  const baseRefUrl = addTokenToGitHttpsUrl(pr.baseRef.repository.url, git.githubToken);

  // Note: Since we use a detached head for rebasing the PR and therefore do not have
  // remote-tracking branches configured, we need to set our expected ref and SHA. This
  // allows us to use `--force-with-lease` for the detached head while ensuring that we
  // never accidentally override upstream changes that have been pushed in the meanwhile.
  // See:
  // https://git-scm.com/docs/git-push#Documentation/git-push.txt---force-with-leaseltrefnamegtltexpectgt
  const forceWithLeaseFlag = `--force-with-lease=${headRefName}:${pr.headRefOid}`;
  const escapedHeadRefName = `'${headRefName.replace(/'/g, "'\\''")}'`;
  const escapedForceWithLeaseFlag = `--force-with-lease=${escapedHeadRefName}:${pr.headRefOid}`;

  // If the PR does not allow maintainers to modify it, exit as the rebased PR cannot
  // be pushed up.
  if (!pr.maintainerCanModify && !pr.viewerDidAuthor) {
    Log.error(
      `Cannot rebase as you did not author the PR and the PR does not allow maintainers` +
        `to modify the PR`,
    );
    return 1;
  }

  try {
    // Fetches are done with --deepen=500 increase the likelihood of finding a common ancestor when
    // a shallow clone is being used.

    // Fetch the branch at the commit of the PR, and check it out in a detached state.
    Log.info(`Checking out PR #${prNumber} from ${fullHeadRef}`);
    git.run(['fetch', '-q', headRefUrl, '--deepen=500', '--', headRefName]);
    git.run(['checkout', '-q', '--detach', 'FETCH_HEAD']);
    // Fetch the PRs target branch and rebase onto it.