feat: switch element (#2)

Author: abeidahmed

.eslintrc.cjs

@@ -13,7 +13,8 @@ module.exports = {
   env: { browser: true },
   overrides: [
     {
-      files: ['src/**/*.spec.ts'],
+      files: ['packages/**/*.test.ts'],
+      globals: { describe: true, it: true, beforeEach: true },
       rules: {
         '@typescript-eslint/no-non-null-assertion': 'off',
       },

package.json

@@ -12,18 +12,26 @@
     "lint": "eslint 'packages/**/*.ts'",
     "playground": "yarn workspace @abeidahmed/playground dev",
     "prettier": "prettier --check --log-level warn .",
-    "prettier:fix": "prettier --write --log-level warn ."
+    "prettier:fix": "prettier --write --log-level warn .",
+    "test": "web-test-runner",
+    "test:watch": "web-test-runner --watch"
   },
   "devDependencies": {
+    "@ambiki/impulse": "^0.2.0",
+    "@open-wc/testing": "^4.0.0",
     "@rollup/plugin-typescript": "^11.1.5",
+    "@types/mocha": "^10.0.6",
     "@typescript-eslint/eslint-plugin": "^6.16.0",
     "@typescript-eslint/parser": "^6.16.0",
+    "@web/dev-server-esbuild": "^1.0.1",
+    "@web/test-runner": "^0.18.0",
     "concurrently": "^8.2.2",
     "eslint": "^8.56.0",
     "eslint-config-prettier": "^9.1.0",
     "eslint-plugin-prettier": "^5.1.2",
     "prettier": "^3.1.1",
     "rollup": "^4.9.1",
+    "sinon": "^17.0.1",
     "typescript": "^5.3.3"
   }
 }

packages/core/package.json

@@ -30,5 +30,9 @@
   "scripts": {
     "build": "rollup --config rollup.config.js",
     "build:watch": "rollup --config rollup.config.js --watch"
-  }
+  },
+  "peerDependencies": {
+    "@ambiki/impulse": "^0.2.0"
+  },
+  "devDependencies": {}
 }

packages/core/rollup.config.js

@@ -5,16 +5,29 @@ import typescript from '@rollup/plugin-typescript';
  */
 export default [
   {
-    input: 'src/index.ts',
+    input: ['./src/index.ts'],
     output: [
       {
-        file: 'dist/index.umd.js',
-        format: 'umd',
-        name: 'TailwindCSSElements',
+        dir: 'dist',
+        entryFileNames: '[name].js',
+        format: 'es',
+        preserveModules: true,
+        preserveModulesRoot: 'src',
       },
+    ],
+    external: ['@ambiki/impulse'],
+    plugins: [typescript({ tsconfig: './tsconfig.build.json' })],
+  },
+  {
+    input: './src/index.ts',
+    output: [
       {
-        file: 'dist/index.js',
-        format: 'es',
+        name: 'TailwindCSSElements',
+        file: 'dist/index.umd.js',
+        format: 'umd',
+        globals: {
+          '@ambiki/impulse': 'Impulse',
+        },
       },
     ],
     plugins: [typescript({ tsconfig: './tsconfig.build.json' })],

packages/core/src/elements/switch/README.md

@@ -0,0 +1,64 @@
+# Switch
+
+Switches are a pleasant interface for toggling a value between two states and offer the same semantics and keyboard
+navigation as native checkbox elements.
+
+## Usage
+
+```html
+<twc-switch>
+  <button
+    type="button"
+    class="group relative inline-flex h-[38px] w-[74px] shrink-0 cursor-pointer rounded-full border-2 border-transparent transition-colors duration-200 ease-in-out focus:outline-none focus-visible:ring-2 focus-visible:ring-white/75 bg-indigo-50 aria-checked:bg-indigo-600"
+    data-target="twc-switch.trigger"
+  >
+    <span class="sr-only">Use setting</span>
+    <span
+      aria-hidden="true"
+      class="pointer-events-none inline-block h-[34px] w-[34px] transform rounded-full bg-white shadow-lg ring-0 transition duration-200 ease-in-out translate-x-0 group-aria-checked:translate-x-9"
+    ></span>
+  </button>
+</twc-switch>
+```
+
+## Examples
+
+### Default to the checked state
+
+You can set the `checked` attribute on the element and it will be checked by default.
+
+```html
+<twc-switch checked>
+  <button type="button">...</button>
+</twc-switch>
+```
+
+### Programatically toggling the checked state
+
+```html
+<twc-switch>
+  <button type="button">...</button>
+</twc-switch>
+```
+
+```js
+const switch = document.querySelector('twc-switch');
+
+// On
+switch.checked = true;
+
+// Off
+switch.checked = false;
+```
+
+## Styling different states
+
+Each component exposes the `data-headlessui-state` attribute that you can use to conditionally apply the classes. You
+can use the [`@headlessui/tailwindcss`](https://github.com/tailwindlabs/headlessui/tree/main/packages/%40headlessui-tailwindcss)
+plugin to target this attribute.
+
+## Events
+
+| Name     | Bubbles   | Description                                                              |
+| ------   | --------- | ------------                                                             |
+| `change` | `false`   | This event fires when the switch is toggled on/off via user interaction. |

packages/core/src/elements/switch/index.test.ts

@@ -0,0 +1,91 @@
+import { expect, fixture, html } from '@open-wc/testing';
+import SwitchElement from './index';
+import Sinon from 'sinon';
+
+describe('Switch', () => {
+  it('sets the attributes', async () => {
+    const el = await fixture<SwitchElement>(html`
+      <twc-switch>
+        <button type="button" data-target="twc-switch.trigger">Switch</button>
+      </twc-switch>
+    `);
+
+    expect(el).not.to.have.attribute('checked');
+
+    const trigger = el.querySelector('button');
+    expect(trigger).to.have.attribute('role', 'switch');
+    expect(trigger).to.have.attribute('tabindex', '0');
+    expect(trigger).to.have.attribute('aria-checked', 'false');
+    expect(el).to.have.attribute('data-headlessui-state', '');
+  });
+
+  it('defaults to the checked state', async () => {
+    const el = await fixture<SwitchElement>(html`
+      <twc-switch checked>
+        <button type="button" data-target="twc-switch.trigger">Switch</button>
+      </twc-switch>
+    `);
+
+    expect(el).to.have.attribute('checked');
+
+    const trigger = el.querySelector('button');
+    expect(trigger).to.have.attribute('aria-checked', 'true');
+    expect(el).to.have.attribute('data-headlessui-state', 'checked');
+  });
+
+  it('toggles the checked state', async () => {
+    const el = await fixture<SwitchElement>(html`
+      <twc-switch>
+        <button type="button" data-target="twc-switch.trigger">Switch</button>
+      </twc-switch>
+    `);
+    const changeHandler = Sinon.spy();
+    el.addEventListener('change', changeHandler);
+
+    const trigger = el.querySelector('button')!;
+    trigger.click();
+    expect(el).to.have.attribute('checked');
+    expect(trigger).to.have.attribute('aria-checked', 'true');
+    expect(el).to.have.attribute('data-headlessui-state', 'checked');
+    expect(changeHandler.calledOnce).to.be.true;
+
+    trigger.click();
+    expect(el).not.to.have.attribute('checked');
+    expect(trigger).to.have.attribute('aria-checked', 'false');
+    expect(el).to.have.attribute('data-headlessui-state', '');
+    expect(changeHandler.calledTwice).to.be.true;
+  });
+
+  it('programatically toggling the checked state', async () => {
+    const el = await fixture<SwitchElement>(html`
+      <twc-switch>
+        <button type="button" data-target="twc-switch.trigger">Switch</button>
+      </twc-switch>
+    `);
+    const changeHandler = Sinon.spy();
+    el.addEventListener('change', changeHandler);
+
+    el.checked = true;
+
+    const trigger = el.querySelector('button')!;
+    expect(trigger).to.have.attribute('aria-checked', 'true');
+    expect(el).to.have.attribute('data-headlessui-state', 'checked');
+    expect(changeHandler.called).to.be.false;
+
+    el.checked = false;
+    expect(trigger).to.have.attribute('aria-checked', 'false');
+    expect(el).to.have.attribute('data-headlessui-state', '');
+    expect(changeHandler.called).to.be.false;
+  });
+
+  it('specified tabindex is not overridden', async () => {
+    const el = await fixture<SwitchElement>(html`
+      <twc-switch>
+        <button type="button" data-target="twc-switch.trigger" tabindex="-1">Switch</button>
+      </twc-switch>
+    `);
+
+    const trigger = el.querySelector('button')!;
+    expect(trigger).to.have.attribute('tabindex', '-1');
+  });
+});

packages/core/src/elements/switch/index.ts

@@ -0,0 +1,61 @@
+import { ImpulseElement, property, registerElement, target } from '@ambiki/impulse';
+
+@registerElement('twc-switch')
+export default class SwitchElement extends ImpulseElement {
+  /**
+   * Whether or not the switch is checked. To make the switch checked by default, set the `checked` attribute.
+   */
+  @property({ type: Boolean }) checked = false;
+
+  @target() trigger: HTMLButtonElement;
+
+  constructor() {
+    super();
+    this.handleToggle = this.handleToggle.bind(this);
+  }
+
+  /**
+   * Called when the `trigger` element is connected to the DOM.
+   */
+  triggerConnected(trigger: HTMLButtonElement) {
+    trigger.setAttribute('role', 'switch');
+    if (!trigger.hasAttribute('tabindex')) {
+      trigger.setAttribute('tabindex', '0');
+    }
+    this.syncState(this.checked);
+    trigger.addEventListener('click', this.handleToggle);
+  }
+
+  /**
+   * Called when the `trigger` element is removed from the DOM.
+   */
+  triggerDisconnected(trigger: HTMLButtonElement) {
+    trigger.removeEventListener('click', this.handleToggle);
+  }
+
+  /**
+   * Called when the `checked` property changes.
+   */
+  checkedChanged(value: boolean) {
+    this.syncState(value);
+  }
+
+  private handleToggle() {
+    this.checked = !this.checked;
+    this.emit('change', { prefix: false, bubbles: false });
+  }
+
+  private syncState(state: boolean) {
+    this.trigger.setAttribute('aria-checked', state.toString());
+    this.setAttribute('data-headlessui-state', state ? 'checked' : '');
+  }
+}
+
+declare global {
+  interface Window {
+    SwitchElement: typeof SwitchElement;
+  }
+  interface HTMLElementTagNameMap {
+    'twc-switch': SwitchElement;
+  }
+}

packages/core/src/index.ts

@@ -1 +1 @@
-export default {};
+import './elements/switch';

packages/core/tsconfig.build.json

@@ -1,9 +1,8 @@
 {
   "extends": "./tsconfig.json",
   "compilerOptions": {
-    "outDir": "./dist",
-    "strictPropertyInitialization": true
+    "outDir": "./dist"
   },
   "include": ["./src"],
-  "exclude": ["./test"]
+  "exclude": ["./src/**/*.test.ts"]
 }

packages/core/tsconfig.json

@@ -1,3 +1,4 @@
 {
-  "extends": "../../tsconfig.json"
+  "extends": "../../tsconfig.json",
+  "include": ["./src/*"]
 }