Ability to opt-out of offline mirror (#3009)

Configs are merged with configs in parent directories, so currently if a .yarnrc in a parent directory enables the offline mirror, all projects in child directories would also use the offline mirror.

This commit allows a child directory to opt-out of the offline mirror in their own .yarnrc with `yarn-offline-mirror false`.

Previously if you specified `false` you'd get an exception as false is parsed as boolean but it expects a string.

Also included tests verifying the existing .yarnrc merging behaviour (previously wasn't covered).

t14078443

__tests__/commands/_helpers.js

@@ -64,7 +64,7 @@ export async function run<T, R>(
   ) => Promise<T> | T,
   args: Array<string>,
   flags: Object,
-  name: string,
+  name: string | { source: string, cwd: string },
   checkInstalled: ?(config: Config, reporter: R, install: T) => ?Promise<void>,
   beforeInstall: ?(cwd: string) => ?Promise<void>,
 ): Promise<void> {
@@ -81,9 +81,14 @@ export async function run<T, R>(
 
   let cwd;
   if (fixturesLoc) {
-    const dir = path.join(fixturesLoc, name);
+    const source = typeof name === 'string' ? name : name.source;
+
+    const dir = path.join(fixturesLoc, source);
     cwd = await fs.makeTempDir(path.basename(dir));
     await fs.copy(dir, cwd, reporter);
+    if (typeof name !== 'string') {
+      cwd = path.join(cwd, name.cwd);
+    }
   } else {
     // if fixture loc is not set then CWD is some empty temp dir
     cwd = await fs.makeTempDir();

__tests__/commands/install/integration.js

@@ -6,6 +6,7 @@ import {run as cache} from '../../../src/cli/commands/cache.js';
 import {run as check} from '../../../src/cli/commands/check.js';
 import * as constants from '../../../src/constants.js';
 import * as reporters from '../../../src/reporters/index.js';
+import {parse} from '../../../src/lockfile/wrapper.js';
 import {Install} from '../../../src/cli/commands/install.js';
 import Lockfile from '../../../src/lockfile/wrapper.js';
 import * as fs from '../../../src/util/fs.js';
@@ -580,6 +581,42 @@ if (process.platform !== 'win32') {
   });
 }
 
+test.concurrent('offline mirror can be enabled from parent dir', (): Promise<void> => {
+  const fixture = {source: 'offline-mirror-configuration', cwd: 'enabled-from-parent'};
+  return runInstall({}, fixture, async (config, reporter) => {
+    const rawLockfile = await fs.readFile(path.join(config.cwd, 'yarn.lock'));
+    const lockfile = parse(rawLockfile);
+    expect(lockfile['mime-types@2.1.14'].resolved).toEqual(
+      'https://registry.yarnpkg.com/mime-types/-/mime-types-2.1.14.tgz#f7ef7d97583fcaf3b7d282b6f8b5679dab1e94ee',
+    );
+    expect(await fs.exists(path.join(config.cwd, '../offline-mirror/mime-types-2.1.14.tgz'))).toBe(true);
+  });
+});
+
+test.concurrent('offline mirror can be enabled from parent dir, with merging of own .yarnrc', (): Promise<void> => {
+  const fixture = {source: 'offline-mirror-configuration', cwd: 'enabled-from-parent-merge'};
+  return runInstall({}, fixture, async (config, reporter) => {
+    const rawLockfile = await fs.readFile(path.join(config.cwd, 'yarn.lock'));
+    const lockfile = parse(rawLockfile);
+    expect(lockfile['mime-types@2.1.14'].resolved).toEqual(
+      'https://registry.yarnpkg.com/mime-types/-/mime-types-2.1.14.tgz#f7ef7d97583fcaf3b7d282b6f8b5679dab1e94ee',
+    );
+    expect(await fs.exists(path.join(config.cwd, '../offline-mirror/mime-types-2.1.14.tgz'))).toBe(true);
+  });
+});
+
+test.concurrent('offline mirror can be disabled locally', (): Promise<void> => {
+  const fixture = {source: 'offline-mirror-configuration', cwd: 'disabled-locally'};
+  return runInstall({}, fixture, async (config, reporter) => {
+    const rawLockfile = await fs.readFile(path.join(config.cwd, 'yarn.lock'));
+    const lockfile = parse(rawLockfile);
+    expect(lockfile['mime-types@2.1.14'].resolved).toEqual(
+      'https://registry.yarnpkg.com/mime-types/-/mime-types-2.1.14.tgz#f7ef7d97583fcaf3b7d282b6f8b5679dab1e94ee',
+    );
+    expect(await fs.exists(path.join(config.cwd, '../offline-mirror/mime-types-2.1.14.tgz'))).toBe(false);
+  });
+});
+
 // sync test because we need to get all the requests to confirm their validity
 test('install a scoped module from authed private registry', (): Promise<void> => {
   return runInstall({noLockfile: true}, 'install-from-authed-private-registry', async (config) => {

__tests__/fixtures/install/offline-mirror-configuration/.yarnrc

@@ -0,0 +1 @@
+yarn-offline-mirror "./offline-mirror"

__tests__/fixtures/install/offline-mirror-configuration/disabled-locally/.yarnrc

@@ -0,0 +1 @@
+yarn-offline-mirror false

__tests__/fixtures/install/offline-mirror-configuration/disabled-locally/package.json

@@ -0,0 +1,5 @@
+{
+  "dependencies": {
+    "mime-types": "2.1.14"
+  }
+}

__tests__/fixtures/install/offline-mirror-configuration/enabled-from-parent-merge/.yarnrc

@@ -0,0 +1 @@
+something else

__tests__/fixtures/install/offline-mirror-configuration/enabled-from-parent-merge/package.json

@@ -0,0 +1,5 @@
+{
+  "dependencies": {
+    "mime-types": "2.1.14"
+  }
+}

__tests__/fixtures/install/offline-mirror-configuration/enabled-from-parent/package.json

@@ -0,0 +1,5 @@
+{
+  "dependencies": {
+    "mime-types": "2.1.14"
+  }
+}

src/config.js

@@ -389,6 +389,10 @@ export default class Config {
 
       const registryMirrorPath = registry.config['yarn-offline-mirror'];
 
+      if (registryMirrorPath === false) {
+        return null;
+      }
+
       if (registryMirrorPath == null) {
         continue;
       }