Support noFrozenLockfile options

README.md

@@ -361,9 +361,10 @@ Using yarn will switch the whole packaging pipeline to use yarn, so does it use
 
 The yarn packager supports the following `packagerOptions`:
 
-| Option        | Type | Default | Description |
-|---------------|------|---------|-------------|
-| ignoreScripts | bool | true    | Do not execute package.json hook scripts on install |
+| Option           | Type | Default  | Description                                         |
+|------------------|------|----------|-----------------------------------------------------|
+| ignoreScripts    | bool | false    | Do not execute package.json hook scripts on install |
+| noFrozenLockfile | bool | false    | Do not require an up-to-date yarn.lock              |
 
 ##### Common packager options
 

lib/packagers/yarn.js

@@ -5,6 +5,7 @@
  * Yarn specific packagerOptions (default):
  *   flat (false) - Use --flat with install
  *   ignoreScripts (false) - Do not execute scripts during install
+ *   noFrozenLockfile (false) - Do not require an up-to-date yarn.lock
  */
 
 const _ = require('lodash');
@@ -117,9 +118,12 @@ class Yarn {
 
   static install(cwd, packagerOptions) {
     const command = /^win/.test(process.platform) ? 'yarn.cmd' : 'yarn';
-    const args = [ 'install', '--frozen-lockfile', '--non-interactive' ];
+    const args = [ 'install', '--non-interactive' ];
 
     // Convert supported packagerOptions
+    if (!packagerOptions.noFrozenLockfile) {
+      args.push('--frozen-lockfile');
+    }
     if (packagerOptions.ignoreScripts) {
       args.push('--ignore-scripts');
     }

lib/packagers/yarn.test.js

@@ -218,7 +218,7 @@ describe('yarn', () => {
         expect(Utils.spawnProcess).to.have.been.calledOnce;
         expect(Utils.spawnProcess).to.have.been.calledWithExactly(
           sinon.match(/^yarn/),
-          [ 'install', '--frozen-lockfile', '--non-interactive' ],
+          [ 'install', '--non-interactive', '--frozen-lockfile' ],
           {
             cwd: 'myPath'
           }
@@ -234,7 +234,23 @@ describe('yarn', () => {
         expect(Utils.spawnProcess).to.have.been.calledOnce;
         expect(Utils.spawnProcess).to.have.been.calledWithExactly(
           sinon.match(/^yarn/),
-          [ 'install', '--frozen-lockfile', '--non-interactive', '--ignore-scripts' ],
+          [ 'install', '--non-interactive', '--frozen-lockfile', '--ignore-scripts' ],
+          {
+            cwd: 'myPath'
+          }
+        );
+        return null;
+      });
+    });
+
+    it('should use noFrozenLockfile option', () => {
+      Utils.spawnProcess.returns(BbPromise.resolve({ stdout: 'installed successfully', stderr: '' }));
+      return expect(yarnModule.install('myPath', { noFrozenLockfile: true })).to.be.fulfilled.then(result => {
+        expect(result).to.be.undefined;
+        expect(Utils.spawnProcess).to.have.been.calledOnce;
+        expect(Utils.spawnProcess).to.have.been.calledWithExactly(
+          sinon.match(/^yarn/),
+          [ 'install', '--non-interactive' ],
           {
             cwd: 'myPath'
           }