address comments

README.md

@@ -338,11 +338,8 @@ module.exports = function (api) {
           useESModules: true,
         },
       ],
-      [require.resolve("@babel/plugin-proposal-decorators"), { legacy: true }],
-      [require.resolve("@babel/plugin-proposal-class-properties")],
-
       // this is where all the ember required plugins would reside
-      ...emberPlugins({ ...options }),
+      ...emberPlugins(__dirname, { ...options }),
     ],
   };
 };
@@ -351,15 +348,16 @@ module.exports = function (api) {
 #### Ember Plugins
 
 Ember Plugins is a helper function that returns a list of plugins that are required for transpiling Ember correctly. You can import this helper function and add it to your existing `babel.config` file.
-
+The first argument is **required** which is the path to the root of your project (generally `__dirname`).
 **Config options:**
 
-```json
+```js
 {
   disableModuleResolution: boolean, // determines if you want the module resolution enabled
   emberDataVersionRequiresPackagesPolyfill: boolean, // enable ember data's polyfill
   shouldIgnoreJQuery: boolean, // ignore jQuery
   shouldIgnoreEmberString: boolean, // ignore ember string
+  shouldIgnoreDecoratorAndClassPlugins: boolean, // disable decorator plugins
   disableEmberModulesAPIPolyfill: boolean, // disable ember modules API polyfill
 }
 ```

index.js

@@ -33,7 +33,9 @@ let count = 0;
 module.exports = {
   name: 'ember-cli-babel',
   configKey: 'ember-cli-babel',
-  emberPlugins,
+  // Note: This is not used internally for this addon, this is added for users to import this function for getting the ember specific
+  // babel plugins. Eg: adding ember specific babel plugins in their babel.config.js.
+  buildEmberPlugins: emberPlugins,
 
   init() {
     this._super.init && this._super.init.apply(this, arguments);
@@ -84,8 +86,7 @@ module.exports = {
        sourceMaps,
        throwUnlessParallelizable,
        filterExtensions: _getExtensions(config, this.parent),
-       plugins: [],
-       presets: []
+       plugins: []
      };
 
      if (shouldCompileModules) {

lib/ember-plugins.js

@@ -1,3 +1,6 @@
+const semver = require("semver");
+const resolvePackagePath = require("resolve-package-path");
+
 function _getDebugMacroPlugins() {
   const isProduction = process.env.EMBER_ENV === "production";
   const isDebug = !isProduction;
@@ -50,27 +53,49 @@ function _emberVersionRequiresModulesAPIPolyfill() {
   return true;
 }
 
-function _getEmberModulesAPIPolyfill(config) {
+function _getEmberModulesAPIPolyfill(appRoot, config) {
   if (config.disableEmberModulesAPIPolyfill) {
     return;
   }
 
   if (_emberVersionRequiresModulesAPIPolyfill()) {
-    const ignore = _getEmberModulesAPIIgnore(config);
+    const ignore = _getEmberModulesAPIIgnore(appRoot, config);
 
     return [
       [require.resolve("babel-plugin-ember-modules-api-polyfill"), { ignore }],
     ];
   }
 }
 
-function _getEmberModulesAPIIgnore(config) {
+function _shouldIgnoreEmberString(appRoot) {
+  return resolvePackagePath("@ember/string", appRoot) !== null;
+}
+
+function _shouldIgnoreJQuery(appRoot) {
+  let packagePath = resolvePackagePath("@ember/jquery", appRoot);
+  if (packagePath === null) {
+    return true;
+  }
+  let pkg = require(packagePath);
+  return pkg && semver.gt(pkg.version, "0.6.0");
+}
+
+function _emberDataVersionRequiresPackagesPolyfill(appRoot) {
+  let packagePath = resolvePackagePath("ember-data", appRoot);
+  if (packagePath === null) {
+    return false;
+  }
+  let pkg = require(packagePath);
+  return pkg && semver.lt(pkg.version, "3.12.0-alpha.0");
+}
+
+function _getEmberModulesAPIIgnore(appRoot, config) {
   const ignore = {
     "@ember/debug": ["assert", "deprecate", "warn"],
     "@ember/application/deprecations": ["deprecate"],
   };
 
-  if (config.shouldIgnoreEmberString) {
+  if (config.shouldIgnoreEmberString || _shouldIgnoreEmberString(appRoot)) {
     ignore["@ember/string"] = [
       "fmt",
       "loc",
@@ -86,23 +111,24 @@ function _getEmberModulesAPIIgnore(config) {
       "getString",
     ];
   }
-  if (config.shouldIgnoreJQuery) {
+  if (config.shouldIgnoreJQuery || _shouldIgnoreJQuery(appRoot)) {
     ignore["jquery"] = ["default"];
   }
 
   return ignore;
 }
 
-function _getEmberDataPackagesPolyfill(config) {
+function _getEmberDataPackagesPolyfill(appRoot, config) {
   if (config.emberDataVersionRequiresPackagesPolyfill) {
     return [[require.resolve("babel-plugin-ember-data-packages-polyfill")]];
   }
+  return _emberDataVersionRequiresPackagesPolyfill(appRoot);
 }
 
 function _getModuleResolutionPlugins(config) {
   if (!config.disableModuleResolution) {
     const resolvePath = require("../lib/relative-module-paths")
-      .resolveRelativeModulePath;
+    .resolveRelativeModulePath;
     return [
       [require.resolve("babel-plugin-module-resolver"), { resolvePath }],
       [
@@ -113,17 +139,29 @@ function _getModuleResolutionPlugins(config) {
   }
 }
 
-module.exports = function (config = {}) {
+function _getProposalDecoratorsAndClassPlugins(config) {
+  if (!config.shouldIgnoreDecoratorAndClassPlugins) {
+    return [
+      ["@babel/plugin-proposal-decorators", { legacy: true }],
+      ["@babel/plugin-proposal-class-properties"],
+    ];
+  }
+}
+
+module.exports = function (appRoot, config = {}) {
   return []
     .concat(
-      _getDebugMacroPlugins(),
-      _getEmberModulesAPIPolyfill(config),
-      _getEmberDataPackagesPolyfill(config),
+      _getProposalDecoratorsAndClassPlugins(config),
+      _getDebugMacroPlugins(appRoot),
+      _getEmberModulesAPIPolyfill(appRoot, config),
+      _getEmberDataPackagesPolyfill(appRoot, config),
       _getModuleResolutionPlugins(config)
     )
     .filter(Boolean);
 };
+
 module.exports.getDebugMacroPlugins = _getDebugMacroPlugins;
 module.exports.getEmberModulesAPIPolyfill = _getEmberModulesAPIPolyfill;
 module.exports.getEmberDataPackagesPolyfill = _getEmberDataPackagesPolyfill;
 module.exports.getModuleResolutionPlugins = _getModuleResolutionPlugins;
+module.exports.getProposalDecoratorsAndClassPlugins = _getProposalDecoratorsAndClassPlugins;

package.json

@@ -64,6 +64,7 @@
     "ember-cli-version-checker": "^4.1.0",
     "ensure-posix-path": "^1.0.2",
     "fixturify-project": "^1.10.0",
+    "resolve-package-path": "^3.1.0",
     "rimraf": "^3.0.1",
     "semver": "^5.5.0"
   },

yarn.lock

@@ -5572,6 +5572,13 @@ [email protected], is-ci@^2.0.0:
   dependencies:
     ci-info "^2.0.0"
 
+is-core-module@^2.1.0:
+  version "2.2.0"
+  resolved "https://registry.yarnpkg.com/is-core-module/-/is-core-module-2.2.0.tgz#97037ef3d52224d85163f5597b2b63d9afed981a"
+  integrity sha512-XRAfAdyyY5F5cOXn7hYQDqh2Xmii+DEfIcQGxK/uNwMHhIkPWO0g8msXcbzLe+MpGoR951MlqM/2iIlU4vKDdQ==
+  dependencies:
+    has "^1.0.3"
+
 is-data-descriptor@^0.1.4:
   version "0.1.4"
   resolved "https://registry.yarnpkg.com/is-data-descriptor/-/is-data-descriptor-0.1.4.tgz#0b5ee648388e2c860282e793f1856fec3f301b56"
@@ -8236,6 +8243,14 @@ resolve-package-path@^2.0.0:
     path-root "^0.1.1"
     resolve "^1.13.1"
 
+resolve-package-path@^3.1.0:
+  version "3.1.0"
+  resolved "https://registry.yarnpkg.com/resolve-package-path/-/resolve-package-path-3.1.0.tgz#35faaa5d54a9c7dd481eb7c4b2a44410c9c763d8"
+  integrity sha512-2oC2EjWbMJwvSN6Z7DbDfJMnD8MYEouaLn5eIX0j8XwPsYCVIyY9bbnX88YHVkbr8XHqvZrYbxaLPibfTYKZMA==
+  dependencies:
+    path-root "^0.1.1"
+    resolve "^1.17.0"
+
 resolve-url@^0.2.1:
   version "0.2.1"
   resolved "https://registry.yarnpkg.com/resolve-url/-/resolve-url-0.2.1.tgz#2c637fe77c893afd2a663fe21aa9080068e2052a"
@@ -8255,6 +8270,14 @@ resolve@^1.1.6, resolve@^1.10.0, resolve@^1.12.0, resolve@^1.13.1, resolve@^1.3.
   dependencies:
     path-parse "^1.0.6"
 
+resolve@^1.17.0:
+  version "1.19.0"
+  resolved "https://registry.yarnpkg.com/resolve/-/resolve-1.19.0.tgz#1af5bf630409734a067cae29318aac7fa29a267c"
+  integrity sha512-rArEXAgsBG4UgRGcynxWIWKFvh/XZCcS8UJdHhwy91zwAvCZIbcs+vAbflgBnNjYMs/i/i+/Ux6IZhML1yPvxg==
+  dependencies:
+    is-core-module "^2.1.0"
+    path-parse "^1.0.6"
+
 [email protected], responselike@^1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/responselike/-/responselike-1.0.2.tgz#918720ef3b631c5642be068f15ade5a46f4ba1e7"