[scripts/update_prs] implement script to merge base branch into prs (#38302)

scripts/update_prs.js

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+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+require('../src/setup_node_env');
+require('../src/dev/prs/run_update_prs_cli');

src/dev/prs/github_api.ts

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+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import axios, { AxiosError, AxiosResponse } from 'axios';
+
+import { createFailError } from '../run';
+
+interface ResponseError extends AxiosError {
+  request: any;
+  response: AxiosResponse;
+}
+const isResponseError = (error: any): error is ResponseError =>
+  error && error.response && error.response.status;
+
+const isRateLimitError = (error: any) =>
+  isResponseError(error) &&
+  error.response.status === 403 &&
+  `${error.response.headers['X-RateLimit-Remaining']}` === '0';
+
+export class GithubApi {
+  private api = axios.create({
+    baseURL: 'https://api.github.com/',
+    headers: {
+      Accept: 'application/vnd.github.v3+json',
+      'User-Agent': 'kibana/update_prs_cli',
+      ...(this.accessToken ? { Authorization: `token ${this.accessToken} ` } : {}),
+    },
+  });
+
+  constructor(private accessToken?: string) {}
+
+  async getPrInfo(prNumber: number) {
+    try {
+      const resp = await this.api.get(`repos/elastic/kibana/pulls/${prNumber}`);
+      const targetRef: string = resp.data.base && resp.data.base.ref;
+      if (!targetRef) {
+        throw new Error('unable to read base ref from pr info');
+      }
+
+      const owner: string = resp.data.head && resp.data.head.user && resp.data.head.user.login;
+      if (!owner) {
+        throw new Error('unable to read owner info from pr info');
+      }
+
+      const sourceBranch: string = resp.data.head.ref;
+      if (!sourceBranch) {
+        throw new Error('unable to read source branch name from pr info');
+      }
+
+      return {
+        targetRef,
+        owner,
+        sourceBranch,
+      };
+    } catch (error) {
+      if (!isRateLimitError(error)) {
+        throw error;
+      }
+
+      throw createFailError(
+        'github rate limit exceeded, please specify the `--access-token` command line flag and try again'
+      );
+    }
+  }
+}

src/dev/prs/helpers.ts

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+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { Readable } from 'stream';
+import * as Rx from 'rxjs';
+import { takeUntil } from 'rxjs/operators';
+
+/**
+ * Convert a Readable stream to an observable of lines
+ */
+export const getLine$ = (stream: Readable) => {
+  return new Rx.Observable<string>(subscriber => {
+    let buffer = '';
+    return Rx.fromEvent(stream, 'data')
+      .pipe(takeUntil(Rx.fromEvent(stream, 'close')))
+      .subscribe({
+        next(chunk) {
+          buffer += chunk;
+          while (true) {
+            const i = buffer.indexOf('\n');
+            if (i === -1) {
+              break;
+            }
+
+            subscriber.next(buffer.slice(0, i));
+            buffer = buffer.slice(i + 1);
+          }
+        },
+        error(error) {
+          subscriber.error(error);
+        },
+        complete() {
+          if (buffer.length) {
+            subscriber.next(buffer);
+            buffer = '';
+          }
+
+          subscriber.complete();
+        },
+      });
+  });
+};

src/dev/prs/pr.ts

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+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { createFlagError } from '../run';
+
+const isNum = (input: string) => {
+  return /^\d+$/.test(input);
+};
+
+export class Pr {
+  static parseInput(input: string) {
+    if (!isNum(input)) {
+      throw createFlagError(`invalid pr number [${input}], expected a number`);
+    }
+
+    return parseInt(input, 10);
+  }
+
+  public readonly remoteRef = `pull/${this.number}/head`;
+
+  constructor(
+    public readonly number: number,
+    public readonly targetRef: string,
+    public readonly owner: string,
+    public readonly sourceBranch: string
+  ) {}
+}

src/dev/prs/run_update_prs_cli.ts

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+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { resolve } from 'path';
+
+import * as Rx from 'rxjs';
+import execa from 'execa';
+import chalk from 'chalk';
+import { first, tap } from 'rxjs/operators';
+import dedent from 'dedent';
+
+import { getLine$ } from './helpers';
+import { run, createFlagError } from '../run';
+import { Pr } from './pr';
+import { GithubApi } from './github_api';
+
+const UPSTREAM_URL = 'git@github.com:elastic/kibana.git';
+
+run(
+  async ({ flags, log }) => {
+    /**
+     * Start off by consuming the necessary flags so that errors from invalid
+     * flags can be thrown before anything serious is done
+     */
+    const accessToken = flags['access-token'];
+    if (typeof accessToken !== 'string' && accessToken !== undefined) {
+      throw createFlagError('invalid --access-token, expected a single string');
+    }
+
+    const repoDir = flags['repo-dir'];
+    if (typeof repoDir !== 'string') {
+      throw createFlagError('invalid --repo-dir, expected a single string');
+    }
+
+    const prNumbers = flags._.map(arg => Pr.parseInput(arg));
+
+    /**
+     * Call the Gitub API once for each PR to get the targetRef so we know which branch to pull
+     * into that pr
+     */
+    const api = new GithubApi(accessToken);
+    const prs = await Promise.all(
+      prNumbers.map(async prNumber => {
+        const { targetRef, owner, sourceBranch } = await api.getPrInfo(prNumber);
+        return new Pr(prNumber, targetRef, owner, sourceBranch);
+      })
+    );
+
+    const execInDir = async (cmd: string, args: string[]) => {
+      log.debug(`$ ${cmd} ${args.join(' ')}`);
+
+      const proc = execa(cmd, args, {
+        cwd: repoDir,
+        stdio: ['inherit', 'pipe', 'pipe'],
+      } as any);
+
+      await Promise.all([
+        proc.then(() => log.debug(` - ${cmd} exited with 0`)),
+        Rx.merge(getLine$(proc.stdout), getLine$(proc.stderr))
+          .pipe(tap(line => log.debug(line)))
+          .toPromise(),
+      ]);
+    };
+
+    const init = async () => {
+      // ensure local repo is initialized
+      await execa('git', ['init', repoDir]);
+
+      try {
+        // attempt to init upstream remote
+        await execInDir('git', ['remote', 'add', 'upstream', UPSTREAM_URL]);
+      } catch (error) {
+        if (error.code !== 128) {
+          throw error;
+        }
+
+        // remote already exists, update its url
+        await execInDir('git', ['remote', 'set-url', 'upstream', UPSTREAM_URL]);
+      }
+    };
+
+    const updatePr = async (pr: Pr) => {
+      log.info('Fetching...');
+      await execInDir('git', [
+        'fetch',
+        'upstream',
+        '-fun',
+        `pull/${pr.number}/head:${pr.sourceBranch}`,
+      ]);
+      await execInDir('git', ['reset', '--hard']);
+      await execInDir('git', ['clean', '-fd']);
+
+      log.info('Checking out %s:%s locally', pr.owner, pr.sourceBranch);
+      await execInDir('git', ['checkout', pr.sourceBranch]);
+
+      try {
+        log.info('Pulling in changes from elastic:%s', pr.targetRef);
+        await execInDir('git', ['pull', 'upstream', pr.targetRef, '--no-edit']);
+      } catch (error) {
+        if (!error.stdout.includes('Automatic merge failed;')) {
+          throw error;
+        }
+
+        const resolveConflicts = async () => {
+          log.error(chalk.red('Conflict resolution required'));
+          log.info(
+            dedent(chalk`
+              Please resolve the merge conflicts in ${repoDir} in another terminal window.
+              Once the conflicts are resolved run the following in the other window:
+
+                git commit --no-edit
+
+              {bold hit the enter key when complete}
+            `) + '\n'
+          );
+
+          await getLine$(process.stdin)
+            .pipe(first())
+            .toPromise();
+
+          try {
+            await execInDir('git', ['diff-index', '--quiet', 'HEAD', '--']);
+          } catch (_) {
+            log.error(`Uncommitted changes in ${repoDir}`);
+            await resolveConflicts();
+          }
+        };
+
+        await resolveConflicts();
+      }
+
+      log.info('Pushing changes to %s:%s', pr.owner, pr.sourceBranch);
+      await execInDir('git', [
+        'push',
+        `git@github.com:${pr.owner}/kibana.git`,
+        `HEAD:${pr.sourceBranch}`,
+      ]);
+
+      log.success('updated');
+    };
+
+    await init();
+    for (const pr of prs) {
+      log.info('pr #%s', pr.number);
+      log.indent(4);
+      try {
+        await updatePr(pr);
+      } finally {
+        log.indent(-4);
+      }
+    }
+  },
+  {
+    description: 'Update github PRs with the latest changes from their base branch',
+    usage: 'node scripts/update_prs number [...numbers]',
+    flags: {
+      string: ['repo-dir', 'access-token'],
+      default: {
+        'repo-dir': resolve(__dirname, '../../../data/.update_prs'),
+      },
+    },
+  }
+);