Add prettier!

.eslintrc.js

@@ -2,51 +2,43 @@ module.exports = {
   root: true,
   parserOptions: {
     ecmaVersion: 2017,
-    sourceType: 'module'
+    sourceType: 'module',
   },
-  plugins: [
-    'ember'
-  ],
-  extends: [
-    'eslint:recommended',
-    'plugin:ember/recommended'
-  ],
+  plugins: ['ember', 'prettier'],
+  extends: ['eslint:recommended', 'plugin:ember/recommended', 'prettier'],
   env: {
-    browser: true
+    browser: true,
   },
   rules: {
+    'prettier/prettier': 'error',
   },
   overrides: [
     // node files
     {
       files: [
         '.eslintrc.js',
+        '.prettierrc.js',
         '.template-lintrc.js',
         'ember-cli-build.js',
         'index.js',
         'testem.js',
         'blueprints/*/index.js',
         'config/**/*.js',
-        'tests/dummy/config/**/*.js'
-      ],
-      excludedFiles: [
-        'addon/**',
-        'addon-test-support/**',
-        'app/**',
-        'tests/dummy/app/**'
+        'tests/dummy/config/**/*.js',
       ],
+      excludedFiles: ['addon/**', 'addon-test-support/**', 'app/**', 'tests/dummy/app/**'],
       parserOptions: {
         sourceType: 'script',
-        ecmaVersion: 2015
+        ecmaVersion: 2015,
       },
       env: {
         browser: false,
-        node: true
+        node: true,
       },
       plugins: ['node'],
       rules: Object.assign({}, require('eslint-plugin-node').configs.recommended.rules, {
         // add your custom rules and overrides for node files here
-      })
-    }
-  ]
+      }),
+    },
+  ],
 };

.prettierrc.js

@@ -0,0 +1,5 @@
+module.exports = {
+  singleQuote: true,
+  trailingComma: 'es5',
+  printWidth: 100,
+};

package.json

@@ -38,9 +38,13 @@
     "ember-source": "~3.7.2",
     "ember-source-channel-url": "^1.1.0",
     "ember-try": "^1.0.0",
+    "eslint": "^5.12.1",
+    "eslint-config-prettier": "^4.0.0",
     "eslint-plugin-ember": "^5.2.0",
     "eslint-plugin-node": "^7.0.1",
+    "eslint-plugin-prettier": "^3.0.1",
     "loader.js": "^4.7.0",
+    "prettier": "^1.16.1",
     "qunit-dom": "^0.8.0"
   },
   "engines": {