Convert to Polymer 3, add events type definitions

.eslintrc.json

@@ -1,15 +1,15 @@
 {
-  "extends": "vaadin",
+  "extends": [
+    "eslint:recommended",
+    "plugin:prettier/recommended"
+  ],
+  "plugins": ["prettier"],
   "env": {
     "browser": true,
-    "node": true,
     "es6": true
   },
-  "plugins": [
-    "html"
-  ],
-  "globals": {
-    "Polymer": false,
-    "Vaadin": false
+  "parserOptions": {
+    "sourceType": "module",
+    "ecmaVersion": 2018
   }
 }

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,33 @@
+### Description
+<!-- Example: The `vaadin-checkbox` element does not get checked when clicked. -->
+
+### Live Demo
+<!-- Click "Remix This" and edit -- must be logged in to persist! -->
+https://glitch.com/edit/#!/vaadin-checkbox-issue
+<!-- ...or provide your own repro URL -->
+
+### Steps to Reproduce
+<!-- Example
+1. Put a `vaadin-text-field` element in the page.
+2. Type something into it.
+-->
+
+### Expected Results
+<!-- Example: Checkbox should be checked when clicked. -->
+
+### Actual Results
+<!-- Example: Checkbox is not checked when clicked. -->
+
+### Browsers Affected
+<!-- Check all that apply -->
+- [ ] Chrome
+- [ ] Firefox
+- [ ] Safari
+- [ ] iOS Safari
+- [ ] Android Chrome
+
+### Version
+<!--
+`$ npm ls | grep @vaadin` will show the version of the components.
+-->
+- vaadin-checkbox: vX.X.X

.github/workflows/sauce.yml

@@ -0,0 +1,47 @@
+name: sauce
+
+on:
+  push:
+    branches:
+      - '**'
+    tags-ignore:
+      - '*.*'
+
+jobs:
+  unit-tests:
+    runs-on: ubuntu-latest
+    if: "! contains(toJSON(github.event.commits.*.message), '[skip ci]')"
+
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-node@v1
+      with:
+        node-version: 12
+
+    - name: Install dependencies
+      run: npm install
+
+    - name: SauceLabs tests
+      env:
+        SAUCE_USERNAME: ${{ secrets.SAUCE_USERNAME }}
+        SAUCE_ACCESS_KEY: ${{ secrets.SAUCE_ACCESS_KEY }}
+      run: npm run test:sauce
+
+  visual-tests:
+    runs-on: ubuntu-latest
+    if: "! contains(toJSON(github.event.commits.*.message), '[skip ci]')"
+
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-node@v1
+      with:
+        node-version: 12
+
+    - name: Install dependencies
+      run: npm install
+
+    - name: Visual tests
+      env:
+        SAUCE_USERNAME: ${{ secrets.SAUCE_USERNAME }}
+        SAUCE_ACCESS_KEY: ${{ secrets.SAUCE_ACCESS_KEY }}
+      run: npm run test:visual

.github/workflows/tests.yml

@@ -0,0 +1,43 @@
+name: tests
+
+on: [pull_request]
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-node@v1
+      with:
+        node-version: 12
+
+    - name: Install dependencies
+      run: npm install
+
+    - name: Check version
+      run: npm run check-version
+
+    - name: Lint JavaScript
+      run: npm run lint:js
+
+    - name: Lint CSS
+      run: npm run lint:css
+
+    - name: Lint typings
+      run: npm run lint:types
+
+  unit-tests:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-node@v1
+      with:
+        node-version: 12
+
+    - name: Install dependencies
+      run: npm install
+
+    - name: Unit tests
+      run: npm test

.hermione.conf.js

@@ -0,0 +1,24 @@
+module.exports = {
+  browsers: {
+    chrome: {
+      baseUrl: 'http://localhost:8080/test/visual/',
+      screenshotsDir: (test) => {
+        const folder = test.title.replace(/-(lumo|material)(-)?(rtl|ltr)?/, '');
+        return `test/visual/screens/${folder}`;
+      },
+      desiredCapabilities: {
+        browserName: 'chrome',
+        version: '85.0',
+        platform: 'Windows 10'
+      }
+    }
+  },
+  plugins: {
+    'hermione-esm': {
+      port: 8080
+    },
+    'hermione-sauce': {
+      verbose: false
+    }
+  }
+};

.prettierrc

@@ -0,0 +1,6 @@
+{
+  "singleQuote": true,
+  "printWidth": 120,
+  "trailingComma": "none",
+  "htmlWhitespaceSensitivity": "strict"
+}

.stylelintrc

@@ -1,3 +1,6 @@
 {
-  "extends": "stylelint-config-vaadin"
+  "extends": [
+    "stylelint-config-vaadin",
+    "stylelint-config-prettier"
+  ]
 }