feat: add support for packaging fiddles as ASAR using @electron/asar

etc/fiddle-core.api.md

@@ -111,7 +111,9 @@ export class Fiddle {
 export class FiddleFactory {
     constructor(fiddles?: string);
     // (undocumented)
-    create(src: FiddleSource): Promise<Fiddle | undefined>;
+    create(src: FiddleSource, options?: {
+        packAsAsar?: boolean;
+    }): Promise<Fiddle | undefined>;
     // (undocumented)
     fromEntries(src: Iterable<[string, string]>): Promise<Fiddle>;
     // (undocumented)

package.json

@@ -34,6 +34,7 @@
     "test:ci": "jest --runInBand --coverage"
   },
   "dependencies": {
+    "@electron/asar": "^3.3.1",
     "@electron/get": "^2.0.0",
     "debug": "^4.3.3",
     "env-paths": "^2.2.1",

src/fiddle.ts

@@ -1,5 +1,6 @@
 import * as fs from 'fs-extra';
 import * as path from 'path';
+import * as asar from '@electron/asar';
 import debug from 'debug';
 import simpleGit from 'simple-git';
 import { createHash } from 'crypto';
@@ -31,6 +32,10 @@ export class Fiddle {
  */
 export type FiddleSource = Fiddle | string | Iterable<[string, string]>;
 
+export interface CreateOptions {
+  packAsAsar?: boolean;
+}
+
 export class FiddleFactory {
   constructor(private readonly fiddles: string = DefaultPaths.fiddles) {}
 
@@ -95,16 +100,43 @@ export class FiddleFactory {
     return new Fiddle(path.join(folder, 'main.js'), 'entries');
   }
 
-  public async create(src: FiddleSource): Promise<Fiddle | undefined> {
-    if (src instanceof Fiddle) return src;
+  public async create(
+    src: FiddleSource,
+    options?: CreateOptions,
+  ): Promise<Fiddle | undefined> {
+    let fiddle: Fiddle;
+    if (src instanceof Fiddle) {
+      fiddle = src;
+    } else if (typeof src === 'string') {
+      if (fs.existsSync(src)) {
+        fiddle = await this.fromFolder(src);
+      } else if (/^[0-9A-Fa-f]{32}$/.test(src)) {
+        fiddle = await this.fromGist(src);
+      } else if (/^https:/.test(src) || /\.git$/.test(src)) {
+        fiddle = await this.fromRepo(src);
+      } else {
+        return;
+      }
+    } else {
+      fiddle = await this.fromEntries(src as Iterable<[string, string]>);
+    }
 
-    if (typeof src === 'string') {
-      if (fs.existsSync(src)) return this.fromFolder(src);
-      if (/^[0-9A-Fa-f]{32}$/.test(src)) return this.fromGist(src);
-      if (/^https:/.test(src) || /\.git$/.test(src)) return this.fromRepo(src);
-      return;
+    const { packAsAsar } = options || {};
+    if (packAsAsar) {
+      fiddle = await this.packageFiddleAsAsar(fiddle);
     }
+    return fiddle;
+  }
+
+  private async packageFiddleAsAsar(fiddle: Fiddle): Promise<Fiddle> {
+    const sourceDir = path.dirname(fiddle.mainPath);
+    const asarOutputDir = path.join(this.fiddles, hashString(sourceDir));
+    const asarFilePath = path.join(asarOutputDir, 'app.asar');
+
+    await asar.createPackage(sourceDir, asarFilePath);
+    const packagedFiddle = new Fiddle(asarFilePath, fiddle.source);
 
-    return this.fromEntries(src);
+    await fs.remove(sourceDir);
+    return packagedFiddle;
   }
 }

src/index.ts

@@ -10,7 +10,7 @@ import {
   Mirrors,
   ProgressObject,
 } from './installer';
-import { Fiddle, FiddleFactory, FiddleSource } from './fiddle';
+import { CreateOptions, Fiddle, FiddleFactory, FiddleSource } from './fiddle';
 import {
   BisectResult,
   Runner,
@@ -33,6 +33,7 @@ import { runFromCommandLine } from './command-line';
 export {
   BaseVersions,
   BisectResult,
+  CreateOptions,
   DefaultPaths,
   ElectronBinary,
   ElectronVersions,

src/runner.ts

@@ -22,6 +22,8 @@ export interface RunnerOptions {
   out?: Writable;
   // whether to show config info (e.g. platform os & arch) in the log
   showConfig?: boolean;
+  // whether to run the fiddle from asar
+  runFromAsar?: boolean;
 }
 
 const DefaultRunnerOpts: RunnerOptions = {
@@ -142,7 +144,9 @@ export class Runner {
     // process the input parameters
     opts = { ...DefaultRunnerOpts, ...opts };
     const version = versionIn instanceof SemVer ? versionIn.version : versionIn;
-    const fiddle = await this.fiddleFactory.create(fiddleIn);
+    const fiddle = await this.fiddleFactory.create(fiddleIn, {
+      packAsAsar: opts.runFromAsar,
+    });
     if (!fiddle) throw new Error(`Invalid fiddle: "${inspect(fiddleIn)}"`);
 
     // set up the electron binary and the fiddle

tests/fiddle.test.ts

@@ -1,6 +1,7 @@
 import * as fs from 'fs-extra';
 import * as os from 'os';
 import * as path from 'path';
+import asar from '@electron/asar';
 
 import { Fiddle, FiddleFactory } from '../src/index';
 
@@ -35,6 +36,9 @@ describe('FiddleFactory', () => {
       const dirname = path.dirname(fiddle!.mainPath);
       expect(dirname).not.toEqual(sourceDir);
 
+      // test that main.js file is created (not app.asar)
+      expect(path.basename(fiddle!.mainPath)).toBe('main.js');
+
       // test that the fiddle is kept in the fiddle cache
       expect(path.dirname(dirname)).toBe(fiddleDir);
 
@@ -93,6 +97,41 @@ describe('FiddleFactory', () => {
       expect(fiddle).toBe(fiddleIn);
     });
 
+    it('packages fiddle into ASAR archive', async () => {
+      const sourceDir = fiddleFixture('642fa8daaebea6044c9079e3f8a46390');
+      const fiddle = await fiddleFactory.create(sourceDir, {
+        packAsAsar: true,
+      });
+
+      function normalizeAsarFiles(files: string[]): string[] {
+        return files.map(
+          (f) => f.replace(/^[\\/]/, ''), // Remove leading slash or backslash
+        );
+      }
+
+      // test that app.asar file is created
+      expect(fiddle).toBeTruthy();
+      expect(path.basename(fiddle!.mainPath)).toBe('app.asar');
+
+      // test that the file list is identical
+      const dirname: string = fiddle!.mainPath;
+      const sourceFiles = fs.readdirSync(sourceDir);
+      const asarFiles = normalizeAsarFiles(
+        asar.listPackage(dirname, { isPack: false }),
+      );
+      expect(asarFiles).toStrictEqual(sourceFiles);
+
+      // test that the files' contents are identical
+      for (const file of sourceFiles) {
+        const sourceFileContent = fs.readFileSync(
+          path.join(sourceDir, file),
+          'utf-8',
+        );
+        const asarFileContent = asar.extractFile(dirname, file).toString();
+        expect(asarFileContent).toStrictEqual(sourceFileContent);
+      }
+    });
+
     it.todo('reads fiddles from git repositories');
     it.todo('refreshes the cache if given a previously-cached git repository');
 

tests/runner.test.ts

@@ -1,4 +1,10 @@
-import { Installer, FiddleFactory, Runner, TestResult } from '../src/index';
+import {
+  Installer,
+  FiddleFactory,
+  Runner,
+  TestResult,
+  CreateOptions,
+} from '../src/index';
 import child_process from 'child_process';
 import { EventEmitter } from 'events';
 import * as fs from 'fs-extra';
@@ -58,7 +64,14 @@ async function createFakeRunner({
       install: jest.fn().mockResolvedValue(pathToExecutable),
     } as Pick<Installer, 'install'> as Installer,
     fiddleFactory: {
-      create: jest.fn().mockResolvedValue(generatedFiddle),
+      create: jest.fn().mockImplementation((_, options?: CreateOptions) => {
+        if (options?.packAsAsar)
+          return Promise.resolve({
+            ...generatedFiddle,
+            mainPath: '/path/to/fiddle/app.asar',
+          });
+        return Promise.resolve(generatedFiddle);
+      }),
     } as Pick<FiddleFactory, 'create'> as FiddleFactory,
     paths: {
       versionsCache,
@@ -181,6 +194,31 @@ describe('Runner', () => {
         new Error(`Invalid fiddle: "'invalid-fiddle'"`),
       );
     });
+
+    it('spawns a subprocess with ASAR path when runFromAsar is true', async () => {
+      const runner = await createFakeRunner({});
+      (child_process.spawn as jest.Mock).mockReturnValueOnce(mockSubprocess);
+
+      await runner.spawn('12.0.1', '642fa8daaebea6044c9079e3f8a46390', {
+        out: {
+          write: mockStdout,
+        } as Pick<Writable, 'write'> as Writable,
+        runFromAsar: true,
+      });
+
+      expect(child_process.spawn).toHaveBeenCalledTimes(1);
+      expect(child_process.spawn).toHaveBeenCalledWith(
+        '/path/to/electron/executable',
+        ['/path/to/fiddle/app.asar'],
+        {
+          args: [],
+          headless: false,
+          out: expect.any(Object) as Writable,
+          showConfig: true,
+          runFromAsar: true,
+        },
+      );
+    });
   });
 
   describe('run()', () => {

yarn.lock

@@ -575,6 +575,15 @@
   resolved "https://registry.yarnpkg.com/@bcoe/v8-coverage/-/v8-coverage-0.2.3.tgz#75a2e8b51cb758a7553d6804a5932d7aace75c39"
   integrity sha512-0hYQ8SB4Db5zvZB4axdMHGwEaQjkZzFjQiN9LVYvIFB2nSUHW9tYpxWriPrWDASIxiaXax83REcLxuSdnGPZtw==
 
+"@electron/asar@^3.3.1":
+  version "3.3.1"
+  resolved "https://registry.yarnpkg.com/@electron/asar/-/asar-3.3.1.tgz#cd14e897770d9844673dd7c1dc8944e086e1e0ea"
+  integrity sha512-WtpC/+34p0skWZiarRjLAyqaAX78DofhDxnREy/V5XHfu1XEXbFCSSMcDQ6hNCPJFaPy8/NnUgYuf9uiCkvKPg==
+  dependencies:
+    commander "^5.0.0"
+    glob "^7.1.6"
+    minimatch "^3.0.4"
+
 "@electron/get@^2.0.0":
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/@electron/get/-/get-2.0.0.tgz#d991e68dc089fc66b521ec3ca4021515482bef91"
@@ -1733,6 +1742,11 @@ commander@^2.7.1:
   resolved "https://registry.yarnpkg.com/commander/-/commander-2.20.3.tgz#fd485e84c03eb4881c20722ba48035e8531aeb33"
   integrity sha512-GpVkmM8vF2vQUkj2LvZmD35JxeJOLCwJ9cUkugyk2nuhbv3+mJvpLYYt+0+USMxE+oj+ey/lJEnhZw75x/OMcQ==
 
+commander@^5.0.0:
+  version "5.1.0"
+  resolved "https://registry.yarnpkg.com/commander/-/commander-5.1.0.tgz#46abbd1652f8e059bddaef99bbdcb2ad9cf179ae"
+  integrity sha512-P0CysNDQ7rtVw4QIQtm+MRxV66vKFSvlsQvGYXZWR3qFU0jlMKHZZZgw8e+8DSah4UDKMqnknRDQz+xuQXQ/Zg==
+
 compress-brotli@^1.3.8:
   version "1.3.8"
   resolved "https://registry.yarnpkg.com/compress-brotli/-/compress-brotli-1.3.8.tgz#0c0a60c97a989145314ec381e84e26682e7b38db"
@@ -2362,7 +2376,7 @@ glob-parent@^6.0.2:
   dependencies:
     is-glob "^4.0.3"
 
-glob@^7.1.3:
+glob@^7.1.3, glob@^7.1.6:
   version "7.2.3"
   resolved "https://registry.yarnpkg.com/glob/-/glob-7.2.3.tgz#b8df0fb802bbfa8e89bd1d938b4e16578ed44f2b"
   integrity sha512-nFR0zLpU2YCaRxwoCJvL6UvCH2JFyFVIvwTLsIf21AuHlMskA1hhTdk+LlYJtOlYt9v6dvszD2BGRqBL+iQK9Q==