Upgrade to Ember 4.8 and use Ember Octane syntax.

.editorconfig

@@ -4,7 +4,6 @@
 
 root = true
 
-
 [*]
 end_of_line = lf
 charset = utf-8

.eslintignore

@@ -13,8 +13,13 @@
 # misc
 /coverage/
 !.*
+.*/
+.eslintcache
 
 # ember-try
 /.node_modules.ember-try/
 /bower.json.ember-try
+/npm-shrinkwrap.json.ember-try
 /package.json.ember-try
+/package-lock.json.ember-try
+/yarn.lock.ember-try

.eslintrc.js

@@ -1,53 +1,53 @@
+'use strict';
+
 module.exports = {
   root: true,
   parser: 'babel-eslint',
   parserOptions: {
     ecmaVersion: 2018,
-    sourceType: 'module'
+    sourceType: 'module',
+    ecmaFeatures: {
+      legacyDecorators: true,
+    },
   },
-  plugins: [
-    'ember'
-  ],
+  plugins: ['ember'],
   extends: [
     'eslint:recommended',
-    'plugin:ember/recommended'
+    'plugin:ember/recommended',
+    'plugin:prettier/recommended',
   ],
   env: {
-    browser: true
-  },
-  rules: {
-    'ember/no-jquery': 'error'
+    browser: true,
   },
+  rules: {},
   overrides: [
     // node files
     {
       files: [
-        '.eslintrc.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/**'
+        './.eslintrc.js',
+        './.prettierrc.js',
+        './.template-lintrc.js',
+        './ember-cli-build.js',
+        './index.js',
+        './testem.js',
+        './blueprints/*/index.js',
+        './config/**/*.js',
+        './tests/dummy/config/**/*.js',
       ],
       parserOptions: {
-        sourceType: 'script'
+        sourceType: 'script',
       },
       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
-      })
-    }
-  ]
+      extends: ['plugin:node/recommended'],
+    },
+    {
+      // test files
+      files: ['tests/**/*-test.{js,ts}'],
+      extends: ['plugin:qunit/recommended'],
+    },
+  ],
 };

.gitignore

@@ -12,6 +12,7 @@
 /.env*
 /.pnp*
 /.sass-cache
+/.eslintcache
 /connect.lock
 /coverage/
 /libpeerconnection.log
@@ -22,4 +23,10 @@
 # ember-try
 /.node_modules.ember-try/
 /bower.json.ember-try
+/npm-shrinkwrap.json.ember-try
 /package.json.ember-try
+/package-lock.json.ember-try
+/yarn.lock.ember-try
+
+# broccoli-debug
+/DEBUG/

.prettierignore

@@ -0,0 +1,25 @@
+# unconventional js
+/blueprints/*/files/
+/vendor/
+
+# compiled output
+/dist/
+/tmp/
+
+# dependencies
+/bower_components/
+/node_modules/
+
+# misc
+/coverage/
+!.*
+.eslintcache
+.lint-todo/
+
+# ember-try
+/.node_modules.ember-try/
+/bower.json.ember-try
+/npm-shrinkwrap.json.ember-try
+/package.json.ember-try
+/package-lock.json.ember-try
+/yarn.lock.ember-try

.prettierrc.js

@@ -0,0 +1,5 @@
+'use strict';
+
+module.exports = {
+  singleQuote: true,
+};

.template-lintrc.js

@@ -1,5 +1,5 @@
 'use strict';
 
 module.exports = {
-  extends: 'recommended'
+  extends: 'recommended',
 };

.travis.yml

@@ -3,7 +3,7 @@ language: node_js
 node_js:
   # we recommend testing addons with the same minimum supported node version as Ember CLI
   # so that your addon works for all apps
-  - "8"
+  - '14'
 
 sudo: false
 dist: trusty
@@ -33,8 +33,8 @@ jobs:
 
     # runs tests against each supported Ember version
     - stage: other version tests
-      env: EMBER_TRY_SCENARIO=ember-lts-3.4
-    - env: EMBER_TRY_SCENARIO=ember-lts-3.8
+      env: EMBER_TRY_SCENARIO=ember-lts-4.4
+    - env: EMBER_TRY_SCENARIO=ember-lts-4.8
     - env: EMBER_TRY_SCENARIO=ember-release
     - env: EMBER_TRY_SCENARIO=ember-beta
     - env: EMBER_TRY_SCENARIO=ember-canary
@@ -63,6 +63,6 @@ script:
 
 branches:
   only:
-  - master
-  # tags
-  - /^v\d+\.\d+\.\d+/
+    - master
+    # tags
+    - /^v\d+\.\d+\.\d+/