Add Yarn option

Author: trentmwillis

README.md

@@ -135,6 +135,7 @@ The following options exist:
 | emberDataVersion | Set the version of ember-data, as you would in your `package.json`                      | emberjs/data#master |
 | fixturesPath     | The path to look for your fixture files (see below)                                     | test/fixtures       |
 | noFixtures       | Disables the use of fixture files                                                       | false               |
+| yarn             | Use yarn instead of npm                                                                 | false               |
 
 
 ### Fixtures

lib/utilities/pristine.js

@@ -81,7 +81,7 @@ function installPristineApp(appName, options) {
   chdir(temp.pristinePath);
 
   // Install a vanilla app and cd into it
-  let args = generateArgsForEmberNew(hasNodeModules, hasBowerComponents);
+  let args = generateArgsForEmberNew(hasNodeModules, hasBowerComponents, options);
   let promise = runNew(appName, args)
     .catch(handleResult)
     .then(() => chdir(path.join(temp.pristinePath, appName)));
@@ -91,7 +91,8 @@ function installPristineApp(appName, options) {
     hasNodeModules,
     hasBowerComponents,
     emberVersion: options.emberVersion || 'canary',
-    emberDataVersion: options.emberDataVersion || 'emberjs/data#master'
+    emberDataVersion: options.emberDataVersion || 'emberjs/data#master',
+    yarn: options.yarn || false
   };
 
   promise = promise
@@ -111,9 +112,14 @@ function installPristineApp(appName, options) {
 
 // Generates the arguments to pass to `ember new`. Optionally skipping the
 // npm and/or bower installation phases.
-function generateArgsForEmberNew(skipNpm, skipBower) {
+function generateArgsForEmberNew(skipNpm, skipBower, options) {
   let extraOptions = [];
 
+  if (options.yarn) {
+    debug('using yarn');
+    extraOptions.push('--yarn');
+  }
+
   if (skipNpm) {
     debug('skipping npm');
     extraOptions.push('--skip-npm');
@@ -142,11 +148,19 @@ function nodeModulesSetup(options) {
     promise = promise
       .then(() => {
         debug('installing ember-disable-prototype-extensions');
-        return runCommand('npm', 'install', 'ember-disable-prototype-extensions');
+        if (options.yarn) {
+          return runCommand('yarn', 'add', 'ember-disable-prototype-extensions');
+        } else {
+          return runCommand('npm', 'install', 'ember-disable-prototype-extensions');
+        }
       })
       .then(() => {
         debug("installed ember-disable-prototype-extension");
-        return runCommand('npm', 'install');
+        if (options.yarn) {
+          return runCommand('yarn');
+        } else {
+          return runCommand('npm', 'install');
+        }
       })
       .then(() => debug('installed ember-data ' + emberDataVersion))
       .then(() => symlinkAddon(appName))

test/acceptance/application-test.js

@@ -43,15 +43,16 @@ describe('Acceptance | application', function() {
       promoteHtmlbars();
 
       return app.create('dummy', {
-        fixturesPath: 'tests'
+        fixturesPath: 'tests',
+        yarn: true
       });
     }).then(function() {
       process.chdir(previousCwd);
     }).then(function() {
       app.editPackageJSON(function(pkg) {
         pkg.devDependencies['ember-cli-fastboot'] = process.env.npm_package_devDependencies_ember_cli_fastboot;
       });
-      return app.run('npm', 'install');
+      return app.run('yarn', 'install');
     });
   });