Move check for colocated babel plugin to utils

* extract for easier testing
* remove unused utility package ember-cli-babel-plugin-helpers
* add tests (these previously failed 😭)

Author: Robert Jackson

lib/ember-addon-main.js

@@ -184,13 +184,8 @@ dBabelVersion: ${hasValidBabelVersion};`
       }
     }
 
-    if (this._shouldColocateTemplates()) {
-      const { hasPlugin, addPlugin } = require('ember-cli-babel-plugin-helpers');
-      let colocatedPluginPath = require.resolve('./colocated-babel-plugin');
-
-      if (!hasPlugin(babelPlugins, colocatedPluginPath)) {
-        addPlugin(babelPlugins, colocatedPluginPath);
-      }
+    if (this._shouldColocateTemplates() && !utils.isColocatedBabelPluginRegistered(babelPlugins)) {
+      babelPlugins.push(require.resolve('./colocated-babel-plugin'));
     }
   },
 

lib/utils.js

@@ -34,6 +34,12 @@ function isInlinePrecompileBabelPluginRegistered(plugins) {
   });
 }
 
+function isColocatedBabelPluginRegistered(plugins) {
+  return plugins.some(
+    plugin => typeof plugin === 'string' && plugin === require.resolve('./colocated-babel-plugin')
+  );
+}
+
 function buildOptions(projectConfig, templateCompilerPath, pluginInfo) {
   let EmberENV = projectConfig.EmberENV || {};
 
@@ -248,5 +254,6 @@ module.exports = {
   setup,
   makeCacheKey,
   setupPlugins,
+  isColocatedBabelPluginRegistered,
   isInlinePrecompileBabelPluginRegistered,
 };

node-tests/utils_test.js

@@ -166,4 +166,18 @@ describe('utils', function() {
       assert.strictEqual(utils.isInlinePrecompileBabelPluginRegistered(plugins), true);
     });
   });
+
+  describe('isColocatedBabelPluginRegistered', function() {
+    it('is false when no plugins exist', function() {
+      let plugins = [];
+
+      assert.strictEqual(utils.isColocatedBabelPluginRegistered(plugins), false);
+    });
+
+    it('detects when the plugin exists', function() {
+      let plugins = [require.resolve('../lib/colocated-babel-plugin')];
+
+      assert.strictEqual(utils.isColocatedBabelPluginRegistered(plugins), true);
+    });
+  });
 });