angular-docs-cn/dev-infra/pr/merge/task.ts

121 lines
4.3 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 {GitClient, GitCommandError} from '../../utils/git';
import {MergeConfigWithRemote} from './config';
import {PullRequestFailure} from './failures';
import {isPullRequest, loadAndValidatePullRequest,} from './pull-request';
import {GithubApiMergeStrategy} from './strategies/api-merge';
import {AutosquashMergeStrategy} from './strategies/autosquash-merge';
/** Github OAuth scopes required for the merge task. */
const REQUIRED_SCOPES = ['repo'];
/** Describes the status of a pull request merge. */
export const enum MergeStatus {
UNKNOWN_GIT_ERROR,
DIRTY_WORKING_DIR,
SUCCESS,
FAILED,
GITHUB_ERROR,
}
/** Result of a pull request merge. */
export interface MergeResult {
/** Overall status of the merge. */
status: MergeStatus;
/** List of pull request failures. */
failure?: PullRequestFailure;
}
/**
* Class that accepts a merge script configuration and Github token. It provides
* a programmatic interface for merging multiple pull requests based on their
* labels that have been resolved through the merge script configuration.
*/
export class PullRequestMergeTask {
/** Git client that can be used to execute Git commands. */
git = new GitClient(this._githubToken, {github: this.config.remote});
constructor(
public projectRoot: string, public config: MergeConfigWithRemote,
private _githubToken: string) {}
/**
* Merges the given pull request and pushes it upstream.
* @param prNumber Pull request that should be merged.
* @param force Whether non-critical pull request failures should be ignored.
*/
async merge(prNumber: number, force = false): Promise<MergeResult> {
// Assert the authenticated GitClient has access on the required scopes.
const hasOauthScopes = await this.git.hasOauthScopes(...REQUIRED_SCOPES);
if (hasOauthScopes !== true) {
return {
status: MergeStatus.GITHUB_ERROR,
failure: PullRequestFailure.insufficientPermissionsToMerge(hasOauthScopes.error)
};
}
if (this.git.hasUncommittedChanges()) {
return {status: MergeStatus.DIRTY_WORKING_DIR};
}
const pullRequest = await loadAndValidatePullRequest(this, prNumber, force);
if (!isPullRequest(pullRequest)) {
return {status: MergeStatus.FAILED, failure: pullRequest};
}
const strategy = this.config.githubApiMerge ?
new GithubApiMergeStrategy(this.git, this.config.githubApiMerge) :
new AutosquashMergeStrategy(this.git);
// Branch that is currently checked out so that we can switch back to it once
// the pull request has been merged.
let previousBranch: null|string = null;
// The following block runs Git commands as child processes. These Git commands can fail.
// We want to capture these command errors and return an appropriate merge request status.
try {
previousBranch = this.git.getCurrentBranch();
// Run preparations for the merge (e.g. fetching branches).
await strategy.prepare(pullRequest);
// Perform the merge and capture potential failures.
const failure = await strategy.merge(pullRequest);
if (failure !== null) {
return {status: MergeStatus.FAILED, failure};
}
// Switch back to the previous branch. We need to do this before deleting the temporary
// branches because we cannot delete branches which are currently checked out.
this.git.run(['checkout', '-f', previousBranch]);
await strategy.cleanup(pullRequest);
// Return a successful merge status.
return {status: MergeStatus.SUCCESS};
} catch (e) {
// Catch all git command errors and return a merge result w/ git error status code.
// Other unknown errors which aren't caused by a git command are re-thrown.
if (e instanceof GitCommandError) {
return {status: MergeStatus.UNKNOWN_GIT_ERROR};
}
throw e;
} finally {
// Always try to restore the branch if possible. We don't want to leave
// the repository in a different state than before.
if (previousBranch !== null) {
this.git.runGraceful(['checkout', '-f', previousBranch]);
}
}
}
}