update to Ember v4.12 with ember-cli-update

.ember-cli

@@ -8,8 +8,8 @@
   "disableAnalytics": false,
 
   /**
-  Setting `isTypeScriptProject` to true will force the blueprint generators to generate TypeScript
-  rather than JavaScript by default, when a TypeScript version of a given blueprint is available.
+    Setting `isTypeScriptProject` to true will force the blueprint generators to generate TypeScript
+    rather than JavaScript by default, when a TypeScript version of a given blueprint is available.
   */
   "isTypeScriptProject": false
 }

.eslintrc.js

@@ -4,13 +4,13 @@ module.exports = {
   root: true,
   parser: '@babel/eslint-parser',
   parserOptions: {
-    babelOptions: {
-      plugins: [['@babel/plugin-proposal-decorators', { legacy: true }]],
-    },
-    ecmaVersion: 2018,
+    ecmaVersion: 'latest',
     sourceType: 'module',
-    ecmaFeatures: {
-      legacyDecorators: true,
+    requireConfigFile: false,
+    babelOptions: {
+      plugins: [
+        ['@babel/plugin-proposal-decorators', { decoratorsBeforeExport: true }],
+      ],
     },
     requireConfigFile: false,
   },
@@ -30,6 +30,7 @@ module.exports = {
       files: [
         './.eslintrc.js',
         './.prettierrc.js',
+        './.stylelintrc.js',
         './.template-lintrc.js',
         './ember-cli-build.js',
         './index.js',
@@ -45,8 +46,7 @@ module.exports = {
         browser: false,
         node: true,
       },
-      plugins: ['node'],
-      extends: ['plugin:node/recommended'],
+      extends: ['plugin:n/recommended'],
     },
     {
       // test files

.github/workflows/ci.yml

@@ -67,6 +67,7 @@ jobs:
           - ember-lts-3.24
           - ember-lts-3.28
           - ember-lts-4.4
+          - ember-lts-4.8
           - ember-release
           - ember-beta
           - ember-canary

.npmignore

@@ -18,11 +18,12 @@
 /.gitignore
 /.prettierignore
 /.prettierrc.js
+/.stylelintignore
+/.stylelintrc.js
 /.template-lintrc.js
 /.travis.yml
 /.watchmanconfig
 /bower.json
-/config/ember-try.js
 /CONTRIBUTING.md
 /ember-cli-build.js
 /testem.js

.prettierrc.js

@@ -1,5 +1,12 @@
 'use strict';
 
 module.exports = {
-  singleQuote: true,
+  overrides: [
+    {
+      files: '*.{js,ts}',
+      options: {
+        singleQuote: true,
+      },
+    },
+  ],
 };

.stylelintignore

@@ -0,0 +1,8 @@
+# unconventional files
+/blueprints/*/files/
+
+# compiled output
+/dist/
+
+# addons
+/.node_modules.ember-try/

.stylelintrc.js

@@ -0,0 +1,5 @@
+'use strict';
+
+module.exports = {
+  extends: ['stylelint-config-standard', 'stylelint-prettier/recommended'],
+};