ci(aio): add initial implementation for aio-builds setup

aio/aio-builds-setup/dockerbuild/scripts-js/lib/clean-up/build-cleaner.ts

@@ -0,0 +1,72 @@
+// Imports
+import * as fs from 'fs';
+import * as path from 'path';
+import * as shell from 'shelljs';
+import {GithubPullRequests} from '../common/github-pull-requests';
+
+// Classes
+export class BuildCleaner {
+  // Constructor
+  constructor(protected buildsDir: string, protected repoSlug: string, protected githubToken?: string) {
+    if (!buildsDir) {
+      throw new Error('Missing required parameter \'buildsDir\'!');
+    } else if (!repoSlug) {
+      throw new Error('Missing required parameter \'repoSlug\'!');
+    }
+  }
+
+  // Methods - Public
+  public cleanUp(): Promise<void> {
+    return Promise.all([
+      this.getExistingBuildNumbers(),
+      this.getOpenPrNumbers(),
+    ]).then(([existingBuilds, openPrs]) => this.removeUnnecessaryBuilds(existingBuilds, openPrs));
+  }
+
+  // Methods - Protected
+  protected getExistingBuildNumbers(): Promise<number[]> {
+    return new Promise((resolve, reject) => {
+      fs.readdir(this.buildsDir, (err, files) => {
+        if (err) {
+          return reject(err);
+        }
+
+        const buildNumbers = files.
+          map(Number).       // Convert string to number
+          filter(Boolean);   // Ignore NaN (or 0), because they are not builds
+
+        resolve(buildNumbers);
+      });
+    });
+  }
+
+  protected getOpenPrNumbers(): Promise<number[]> {
+    const githubPullRequests = new GithubPullRequests(this.repoSlug, this.githubToken);
+
+    return githubPullRequests.
+      fetchAll('open').
+      then(prs => prs.map(pr => pr.number));
+  }
+
+  protected removeDir(dir: string) {
+    try {
+      // Undocumented signature (see https://github.com/shelljs/shelljs/pull/663).
+      (shell as any).chmod('-R', 'a+w', dir);
+      shell.rm('-rf', dir);
+    } catch (err) {
+      console.error(`ERROR: Unable to remove '${dir}' due to:`, err);
+    }
+  }
+
+  protected removeUnnecessaryBuilds(existingBuildNumbers: number[], openPrNumbers: number[]) {
+    const toRemove = existingBuildNumbers.filter(num => !openPrNumbers.includes(num));
+
+    console.log(`Existing builds: ${existingBuildNumbers.length}`);
+    console.log(`Open pull requests: ${openPrNumbers.length}`);
+    console.log(`Removing ${toRemove.length} build(s): ${toRemove.join(', ')}`);
+
+    toRemove.
+      map(num => path.join(this.buildsDir, String(num))).
+      forEach(dir => this.removeDir(dir));
+  }
+}