angular-docs-cn/dev-infra/pr/common/checkout-pr.ts

129 lines
4.7 KiB
TypeScript

/**
* @license
* Copyright Google LLC All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
import {types as graphQLTypes} from 'typed-graphqlify';
import {info} from '../../utils/console';
import {addTokenToGitHttpsUrl} from '../../utils/git/github-urls';
import {GitClient} from '../../utils/git/index';
import {getPr} from '../../utils/github';
/* GraphQL schema for the response body for a pending PR. */
const PR_SCHEMA = {
state: graphQLTypes.string,
maintainerCanModify: graphQLTypes.boolean,
viewerDidAuthor: graphQLTypes.boolean,
headRefOid: graphQLTypes.string,
headRef: {
name: graphQLTypes.string,
repository: {
url: graphQLTypes.string,
nameWithOwner: graphQLTypes.string,
},
},
baseRef: {
name: graphQLTypes.string,
repository: {
url: graphQLTypes.string,
nameWithOwner: graphQLTypes.string,
},
},
};
export class UnexpectedLocalChangesError extends Error {
constructor(m: string) {
super(m);
Object.setPrototypeOf(this, UnexpectedLocalChangesError.prototype);
}
}
export class MaintainerModifyAccessError extends Error {
constructor(m: string) {
super(m);
Object.setPrototypeOf(this, MaintainerModifyAccessError.prototype);
}
}
/** Options for checking out a PR */
export interface PullRequestCheckoutOptions {
/** Whether the PR should be checked out if the maintainer cannot modify. */
allowIfMaintainerCannotModify?: boolean;
}
/**
* Rebase the provided PR onto its merge target branch, and push up the resulting
* commit to the PRs repository.
*/
export async function checkOutPullRequestLocally(
prNumber: number, githubToken: string, opts: PullRequestCheckoutOptions = {}) {
/** Authenticated Git client for git and Github interactions. */
const git = new GitClient(githubToken);
// In order to preserve local changes, checkouts cannot occur if local changes are present in the
// git environment. Checked before retrieving the PR to fail fast.
if (git.hasLocalChanges()) {
throw new UnexpectedLocalChangesError('Unable to checkout PR due to uncommitted changes.');
}
/**
* The branch or revision originally checked out before this method performed
* any Git operations that may change the working branch.
*/
const previousBranchOrRevision = git.getCurrentBranchOrRevision();
/* The PR information from Github. */
const pr = await getPr(PR_SCHEMA, prNumber, git);
/** The branch name of the PR from the repository the PR came from. */
const headRefName = pr.headRef.name;
/** The full ref for the repository and branch the PR came from. */
const fullHeadRef = `${pr.headRef.repository.nameWithOwner}:${headRefName}`;
/** The full URL path of the repository the PR came from with github token as authentication. */
const headRefUrl = addTokenToGitHttpsUrl(pr.headRef.repository.url, 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
/** Flag for a force push with leage back to upstream. */
const forceWithLeaseFlag = `--force-with-lease=${headRefName}:${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 && !opts.allowIfMaintainerCannotModify) {
throw new MaintainerModifyAccessError('PR is not set to allow maintainers to modify the PR');
}
try {
// Fetch the branch at the commit of the PR, and check it out in a detached state.
info(`Checking out PR #${prNumber} from ${fullHeadRef}`);
git.run(['fetch', '-q', headRefUrl, headRefName]);
git.run(['checkout', '--detach', 'FETCH_HEAD']);
} catch (e) {
git.checkout(previousBranchOrRevision, true);
throw e;
}
return {
/**
* Pushes the current local branch to the PR on the upstream repository.
*
* @returns true If the command did not fail causing a GitCommandError to be thrown.
* @throws GitCommandError Thrown when the push back to upstream fails.
*/
pushToUpstream: (): true => {
git.run(['push', headRefUrl, `HEAD:${headRefName}`, forceWithLeaseFlag]);
return true;
},
/** Restores the state of the local repository to before the PR checkout occured. */
resetGitState: (): boolean => {
return git.checkout(previousBranchOrRevision, true);
}
};
}