.eslintrc.json

@@ -10,7 +10,6 @@
   "plugins": ["jest", "prettier"],
   "rules": {
     "linebreak-style": ["error", "unix"],
-    "semi": ["error", "always"],
     "valid-jsdoc": [
       "error",
       {

.github/workflows/ci.yml

@@ -0,0 +1,18 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - '**'
+
+jobs:
+  run_tests:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2.3.1
+      - uses: actions/setup-node@v1
+        with:
+          node-version: 14
+      - run: npm ci
+      - run: npm run ci
+      - run: npm run build

.github/workflows/codeql-analysis.yml

@@ -0,0 +1,67 @@
+# For most projects, this workflow file will not need changing; you simply need
+# to commit it to your repository.
+#
+# You may wish to alter this file to override the set of languages analyzed,
+# or to provide custom queries or build logic.
+#
+# ******** NOTE ********
+# We have attempted to detect the languages in your repository. Please check
+# the `language` matrix defined below to confirm you have the correct set of
+# supported CodeQL languages.
+#
+name: "CodeQL"
+
+on:
+  push:
+    branches: [ develop ]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [ develop ]
+  schedule:
+    - cron: '39 19 * * 6'
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [ 'javascript' ]
+        # CodeQL supports [ 'cpp', 'csharp', 'go', 'java', 'javascript', 'python' ]
+        # Learn more:
+        # https://docs.github.com/en/free-pro-team@latest/github/finding-security-vulnerabilities-and-errors-in-your-code/configuring-code-scanning#changing-the-languages-that-are-analyzed
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+
+    # Initializes the CodeQL tools for scanning.
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v1
+      with:
+        languages: ${{ matrix.language }}
+        # If you wish to specify custom queries, you can do so here or in a config file.
+        # By default, queries listed here will override any specified in a config file.
+        # Prefix the list here with "+" to use these queries and those in the config file.
+        # queries: ./path/to/local/query, your-org/your-repo/queries@main
+
+    # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
+    # If this step fails, then you should remove it and run the build manually (see below)
+    - name: Autobuild
+      uses: github/codeql-action/autobuild@v1
+
+    # ℹ️ Command-line programs to run using the OS shell.
+    # 📚 https://git.io/JvXDl
+
+    # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
+    #    and modify them (or add more) to build your code if your project
+    #    uses a compiled language
+
+    #- run: |
+    #   make bootstrap
+    #   make release
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v1

.github/workflows/publish-docs.yml

@@ -0,0 +1,31 @@
+name: Publish Docs
+
+# https://github.com/marketplace/actions/deploy-to-github-pages
+
+on:
+  push:
+    branches:
+      - 'master'
+
+jobs:
+  run_tests:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2.3.1
+        with:
+          persist-credentials: false
+      - uses: actions/setup-node@v1
+        with:
+          node-version: 14
+
+      - run: npm ci
+      - run: npm run build
+      - run: npm run doc
+
+      - uses: JamesIves/github-pages-deploy-action@3.7.1
+        with:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          BRANCH: gh-pages
+          FOLDER: dist
+          CLEAN: true
+          SINGLE_COMMIT: true

.github/workflows/publish-package.yml

@@ -0,0 +1,22 @@
+name: Publish
+
+on:
+  create:
+    tags:
+      - v*
+
+jobs:
+  run_tests:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2.3.1
+      - uses: actions/setup-node@v1
+        with:
+          node-version: 14
+          registry-url: 'https://registry.npmjs.org'
+      - run: npm ci
+      - run: npm run ci
+      - run: npm run build
+      - run: npm publish
+        env:
+          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}

.prettierrc

@@ -1,4 +1,5 @@
 {
+  "semi": false,
   "singleQuote": true,
   "trailingComma": "es5"
 }

README.md

@@ -1,29 +1,80 @@
-# Shifty - A teeny tiny tweening engine in JavaScript
+# Shifty - The fastest JavaScript animation engine on the web
+
+- `master`: [![CI](https://github.com/jeremyckahn/shifty/workflows/CI/badge.svg?branch=master)](https://github.com/jeremyckahn/shifty/actions?query=workflow%3ACI+branch%3Amaster)
+- `develop`: [![CI](https://github.com/jeremyckahn/shifty/workflows/CI/badge.svg?branch=develop)](https://github.com/jeremyckahn/shifty/actions?query=workflow%3ACI+branch%3Adevelop)
 
 Shifty is a tweening engine for JavaScript. It is a lightweight library meant
 to be encapsulated by higher level tools. At its core, Shifty provides:
 
+- Best-in-class performance
 - Interpolation of `Number`s over time (tweening)
 - Playback control of an individual tween
 - Extensibility hooks for key points in the tweening process
+- `Promise` support for `async`/`await` programming
 
 This is useful because it is the least amount of functionality needed to build
 customizable animations. Shifty is optimized to run many times a second with
 minimal processing and memory overhead, which is necessary to achieve smooth
 animations.
 
-## Browser compatibility
-
-Shifty officially supports Evergreen browsers, Safari, and Node. If you
-encounter a browser-specific bug, please [open an issue about
-it](https://github.com/jeremyckahn/shifty/issues/new)!
+```js
+import { tween } from 'shifty'
+;(async () => {
+  const element = document.querySelector('#tweenable')
+
+  const { tweenable } = await tween({
+    render: ({ scale, x }) => {
+      element.style.transform = `translateX(${x}px) scale(${scale})`
+    },
+    easing: 'easeInOutQuad',
+    duration: 500,
+    from: { scale: 1, x: 0 },
+    to: { x: 200 },
+  })
+
+  await tweenable.tween({
+    to: { x: 0 },
+  })
+
+  await tweenable.tween({
+    to: { scale: 3 },
+  })
+})()
+```
 
 ## Installation
 
 ```
 npm install --save shifty
 ```
 
+## Environment compatibility
+
+Shifty officially supports Evergreen browsers, Safari, and Node 10 and above.
+If you encounter a browser-specific bug, please [open an issue about
+it](https://github.com/jeremyckahn/shifty/issues/new)!
+
+### IE compatibility
+
+Shifty is compatible with IE11 (possibly older versions as well), but you
+will need to provide your own polyfills for it to work. If you are using
+https://polyfill.io/, you just need the `es6` features enabled:
+
+```
+https://polyfill.io/v3/polyfill.min.js?features=es6
+```
+
+[Here's a polyfilled demo of Shifty that works with
+IE11](https://codepen.io/jeremyckahn/pen/RwbzvEj). Please see [issue
+#113](https://github.com/jeremyckahn/shifty/issues/113) for background on
+this.
+
+## Support this project!
+
+Shifty is a labor of love that will always be free and open source. If you've
+gotten value out of Shifty, **[please consider supporting the developer with a
+small donation](https://github.com/jeremyckahn#please-help-support-my-work)**!
+
 ## Developing Shifty
 
 First, install the dependencies via npm like so:
@@ -62,25 +113,25 @@ Shifty exposes a UMD module, so you can load it however you like:
 
 ```javascript
 // ES6
-import { tween } from 'shifty';
+import { tween } from 'shifty'
 ```
 
 Or:
 
 ```javascript
 // AMD
 define(['shifty'], function(shifty) {
-  shifty.tween({ from: { x: 0 }, to: { x: 10 } });
-});
+  shifty.tween({ from: { x: 0 }, to: { x: 10 } })
+})
 ```
 
 Or even:
 
 ```javascript
 // CommonJS
-const shifty = require('shifty');
+const { tween } = require('shifty')
 
-shifty.tween({ from: { x: 0 }, to: { x: 10 } });
+tween({ from: { x: 0 }, to: { x: 10 } })
 ```
 
 ## Using Shifty