feat(configuration): add custom registry cli flag (#4238)

**Summary**
implements #792 - addresses a command line flag --registry to specify a registry that overides yarn/npm configuration for installing dependencies.

**Test plan**

Added new tests.

Author: lirantal

__tests__/integration.js

@@ -6,6 +6,7 @@ import makeTemp from './_temp.js';
 import * as fs from '../src/util/fs.js';
 import * as misc from '../src/util/misc.js';
 import * as constants from '../src/constants.js';
+import {explodeLockfile} from './commands/_helpers.js';
 
 jasmine.DEFAULT_TIMEOUT_INTERVAL = 120000;
 
@@ -153,6 +154,54 @@ test('--mutex network', async () => {
   await Promise.all(promises);
 });
 
+describe('--registry option', () => {
+  test('--registry option with npm registry', async () => {
+    const cwd = await makeTemp();
+
+    const registry = 'https://registry.npmjs.org';
+    const packageJsonPath = path.join(cwd, 'package.json');
+    await fs.writeFile(packageJsonPath, JSON.stringify({}));
+
+    await runYarn(['add', 'left-pad', '--registry', registry], {cwd});
+
+    const packageJson = JSON.parse(await fs.readFile(packageJsonPath));
+    const lockfile = explodeLockfile(await fs.readFile(path.join(cwd, 'yarn.lock')));
+
+    expect(packageJson.dependencies['left-pad']).toBeDefined();
+    expect(lockfile).toHaveLength(3);
+    expect(lockfile[2]).toContain(registry);
+  });
+
+  test('--registry option with yarn registry', async () => {
+    const cwd = await makeTemp();
+
+    const registry = 'https://registry.yarnpkg.com';
+    const packageJsonPath = path.join(cwd, 'package.json');
+    await fs.writeFile(packageJsonPath, JSON.stringify({}));
+
+    await runYarn(['add', 'is-array', '--registry', registry], {cwd});
+
+    const packageJson = JSON.parse(await fs.readFile(packageJsonPath));
+    const lockfile = explodeLockfile(await fs.readFile(path.join(cwd, 'yarn.lock')));
+
+    expect(packageJson.dependencies['is-array']).toBeDefined();
+    expect(lockfile).toHaveLength(3);
+    expect(lockfile[2]).toContain(registry);
+  });
+
+  test('--registry option with non-exiting registry and show an error', async () => {
+    const cwd = await makeTemp();
+    const registry = 'https://example-registry-doesnt-exist.com';
+
+    try {
+      await runYarn(['add', 'is-array', '--registry', registry], {cwd});
+    } catch (err) {
+      const stdoutOutput = err.message;
+      expect(stdoutOutput.toString()).toMatch(/getaddrinfo ENOTFOUND example-registry-doesnt-exist\.com/g);
+    }
+  });
+});
+
 test('--cwd option', async () => {
   const cwd = await makeTemp();
 

src/cli/index.js

@@ -91,6 +91,7 @@ export function main({
   commander.option('--cwd <cwd>', 'working directory to use', process.cwd());
   commander.option('--proxy <host>', '');
   commander.option('--https-proxy <host>', '');
+  commander.option('--registry <url>', 'override configuration registry');
   commander.option('--no-progress', 'disable progress bar');
   commander.option('--network-concurrency <number>', 'maximum number of concurrent network requests', parseInt);
   commander.option('--network-timeout <milliseconds>', 'TCP timeout for network requests', parseInt);
@@ -477,6 +478,7 @@ export function main({
       production: commander.production,
       httpProxy: commander.proxy,
       httpsProxy: commander.httpsProxy,
+      registry: commander.registry,
       networkConcurrency: commander.networkConcurrency,
       networkTimeout: commander.networkTimeout,
       nonInteractive: commander.nonInteractive,

src/config.js

@@ -56,6 +56,7 @@ export type ConfigOptions = {
   httpsProxy?: ?string,
 
   commandName?: ?string,
+  registry?: ?string,
 };
 
 type PackageMetadata = {
@@ -193,7 +194,6 @@ export default class Config {
 
   getOption(key: string, expand: boolean = false): mixed {
     const value = this.registries.yarn.getOption(key);
-
     if (expand && typeof value === 'string') {
       return expandPath(value);
     }
@@ -249,7 +249,9 @@ export default class Config {
 
       // instantiate registry
       const registry = new Registry(this.cwd, this.registries, this.requestManager, this.reporter);
-      await registry.init();
+      await registry.init({
+        registry: opts.registry,
+      });
 
       this.registries[key] = registry;
       this.registryFolders.push(registry.folder);

src/registries/base-registry.js

@@ -99,9 +99,10 @@ export default class BaseRegistry {
     });
   }
 
-  async init(): Promise<void> {
+  async init(overrides: Object = {}): Promise<void> {
     this.mergeEnv('yarn_');
     await this.loadConfig();
+    Object.assign(this.config, overrides);
     this.loc = path.join(this.cwd, this.folder);
   }