add emberPlugins as the property in index.js

README.md

@@ -294,7 +294,7 @@ module.exports = function(defaults) {
 ```
 ### Babel config usage
 
-If you want to use the existing babel config from your project instead of the auto-generated one from this addon, then you would need to *opt-in* by passing the config `useBabelConfig: true` in your `ember-cli-build.js` file.
+If you want to use the existing babel config from your project instead of the auto-generated one from this addon, then you would need to *opt-in* by passing the config `useBabelConfig: true` as a child property of `ember-cli-babel` in your `ember-cli-build.js` file.
 
 *Note: If you are using this option, then you have to make sure that you are adding all of the required plugins required for Ember to transpile correctly.*
 
@@ -304,8 +304,8 @@ Example usage:
 //ember-cli-build.js
 
 let app = new EmberAddon(defaults, {
-  useBabelConfig: true,
   "ember-cli-babel": {
+    useBabelConfig: true,
     // ember-cli-babel related options
   },
 });

index.js

@@ -15,6 +15,7 @@ const path = require('path');
 const fs = require('fs'); 
 const getBabelOptions = require('./lib/get-babel-options');
 const findApp = require('./lib/find-app');
+const emberPlugins = require('./lib/ember-plugins');
 
 const APP_BABEL_RUNTIME_VERSION = new WeakMap();
 
@@ -32,6 +33,7 @@ let count = 0;
 module.exports = {
   name: 'ember-cli-babel',
   configKey: 'ember-cli-babel',
+  emberPlugins,
 
   init() {
     this._super.init && this._super.init.apply(this, arguments);
@@ -108,7 +110,9 @@ module.exports = {
     const babelConfigFile = ROOT_CONFIG_FILENAMES.find((fileName) =>
       fs.existsSync(path.resolve(this.parent.root, fileName))
     );
-    const shouldUseBabelConfigFile = config.useBabelConfig && babelConfigFile;
+
+    const customAddonConfig = config['ember-cli-babel'];
+    const shouldUseBabelConfigFile = customAddonConfig && customAddonConfig.useBabelConfig && babelConfigFile;
 
     if (shouldUseBabelConfigFile) {
       options = Object.assign({}, options, {

node-tests/addon-test.js

@@ -1630,7 +1630,9 @@ describe('babel config file', function() {
       project.initializeAddons();
 
       self.addon = project.addons.find(a => { return a.name === 'ember-cli-babel'; });
-      self.addon.parent.options = { useBabelConfig: true };
+      self.addon.parent.options = {
+        "ember-cli-babel": { useBabelConfig: true },
+      };
 
       input = yield createTempDir();
     });
@@ -1694,7 +1696,9 @@ describe('babel config file', function() {
       { noInterop: true },
     ]`);
 
-    this.addon.parent.options = { useBabelConfig: false };
+    this.addon.parent.options = {
+      "ember-cli-babel": { useBabelConfig: false },
+    };
     input.write({
       "foo.js": `export default {};`,
     });