Fix: Allow wa-hide to be cancelled in WaDropdown (#1774)

* Fix: Allow wa-hide to be cancelled in WaDropdown

* add tests around open attribute / property

* update changelog

packages/webawesome/docs/docs/resources/changelog.md

@@ -16,6 +16,7 @@ Components with the <wa-badge variant="warning">Experimental</wa-badge> badge sh
 - 🚨 BREAKING: Changed `appearance="filled outlined"` to `appearance="filled-outlined"` in `<wa-card>` [issue:1671]
 - Fixed a bug in `<wa-slider>` that caused some touch devices to end up with the incorrect value [issue:1703]
 - Fixed a bug in `<wa-card>` that prevented some slots from being detected correctly [discuss:1450]
+- Fixed a bug in `<wa-dropdown>` that caused the browser to hang when cancelling the `wa-hide` event [issue:1483]
 - Improved performance of `<wa-icon>` so initial rendering occurs faster, especially with multiple icons on the page [issue:1729]
 
 ## 3.0.0

packages/webawesome/src/components/dropdown/dropdown.test.ts

@@ -1,4 +1,6 @@
-import { expect, fixture, html } from '@open-wc/testing';
+import { aTimeout, expect, fixture, html, waitUntil } from '@open-wc/testing';
+import sinon from 'sinon';
+import type WaDropdown from './dropdown.js';
 
 describe('<wa-dropdown>', () => {
   it('should render a component', async () => {
@@ -6,4 +8,112 @@ describe('<wa-dropdown>', () => {
 
     expect(el).to.exist;
   });
+
+  it('should respect the open attribute when included', async () => {
+    const el = await fixture<WaDropdown>(html`
+      <wa-dropdown open>
+        <wa-button slot="trigger">Dropdown</wa-button>
+        <wa-dropdown-item>One</wa-dropdown-item>
+      </wa-dropdown>
+    `);
+
+    await el.updateComplete;
+    await aTimeout(200);
+
+    expect(el.open).to.be.true;
+  });
+
+  it('should fire a single show/after-show and hide/after-hide in normal open/close flow', async () => {
+    const el = await fixture<WaDropdown>(html`
+      <wa-dropdown>
+        <wa-button slot="trigger">Dropdown</wa-button>
+        <wa-dropdown-item>One</wa-dropdown-item>
+        <wa-dropdown-item>Two</wa-dropdown-item>
+      </wa-dropdown>
+    `);
+
+    // setup spies to track how often we see different show/hide events
+    const showSpy = sinon.spy();
+    const afterShowSpy = sinon.spy();
+    const hideSpy = sinon.spy();
+    const afterHideSpy = sinon.spy();
+
+    el.addEventListener('wa-show', showSpy);
+    el.addEventListener('wa-after-show', afterShowSpy);
+    el.addEventListener('wa-hide', hideSpy);
+    el.addEventListener('wa-after-hide', afterHideSpy);
+
+    // open the dropdown by triggering a click on the trigger
+    const trigger = el.querySelector<HTMLElement>('[slot="trigger"]')!;
+    trigger.click();
+
+    await waitUntil(() => showSpy.calledOnce);
+    await waitUntil(() => afterShowSpy.calledOnce);
+
+    expect(showSpy.callCount).to.equal(1);
+    expect(afterShowSpy.callCount).to.equal(1);
+
+    expect(el.open).to.be.true;
+
+    // close the dropdown by clicking the trigger again
+    trigger.click();
+
+    await waitUntil(() => hideSpy.calledOnce);
+    await waitUntil(() => afterHideSpy.calledOnce);
+
+    expect(hideSpy.callCount).to.equal(1);
+    expect(afterHideSpy.callCount).to.equal(1);
+
+    expect(el.open).to.be.false;
+  });
+
+  it('should fire a single show/after-show and hide/after-hide when wa-hide event is cancelled', async () => {
+    const el = await fixture<WaDropdown>(html`
+      <wa-dropdown>
+        <wa-button slot="trigger">Dropdown</wa-button>
+        <wa-dropdown-item>One</wa-dropdown-item>
+        <wa-dropdown-item>Two</wa-dropdown-item>
+      </wa-dropdown>
+    `);
+
+    // setup spies to track how often we see different show/hide events
+    const showSpy = sinon.spy();
+    const afterShowSpy = sinon.spy();
+    const hideSpy = sinon.spy();
+    const afterHideSpy = sinon.spy();
+
+    el.addEventListener('wa-show', showSpy);
+    el.addEventListener('wa-after-show', afterShowSpy);
+
+    // Intercept wa-hide and prevent it
+    el.addEventListener('wa-hide', event => {
+      event.preventDefault();
+      hideSpy(event);
+    });
+
+    el.addEventListener('wa-after-hide', afterHideSpy);
+
+    // open the dropdown by triggering a click on the trigger
+    const trigger = el.querySelector<HTMLElement>('[slot="trigger"]')!;
+    trigger.click();
+
+    await waitUntil(() => showSpy.calledOnce);
+    await waitUntil(() => afterShowSpy.calledOnce);
+
+    expect(showSpy.callCount).to.equal(1);
+    expect(afterShowSpy.callCount).to.equal(1);
+
+    expect(el.open).to.be.true;
+
+    // click on the trigger (which should do nothing to the open state)
+    trigger.click();
+
+    await waitUntil(() => hideSpy.calledOnce);
+
+    expect(hideSpy.callCount).to.equal(1);
+    // after-hide should not have been called if hide is cancelled
+    expect(afterHideSpy.callCount).to.equal(0);
+
+    expect(el.open).to.be.true;
+  });
 });

packages/webawesome/src/components/dropdown/dropdown.ts

@@ -109,6 +109,18 @@ export default class WaDropdown extends WebAwesomeElement {
 
   async updated(changedProperties: PropertyValues) {
     if (changedProperties.has('open')) {
+      const previousOpen = changedProperties.get('open');
+      // check if the previous value is the same
+      // (if they are, do not trigger menu showing / hiding)
+      if (previousOpen === this.open) {
+        return;
+      }
+      // check if we are changing from undefined to false
+      // (if we are, we can skip menu hiding)
+      if (previousOpen === undefined && this.open === false) {
+        return;
+      }
+
       this.customStates.set('open', this.open);
 
       if (this.open) {
@@ -227,6 +239,12 @@ export default class WaDropdown extends WebAwesomeElement {
       return;
     }
 
+    // if this dropdown is already open, do nothing
+    // (this can happen when wa-hide was cancelled)
+    if (this.popup.active) {
+      return;
+    }
+
     openDropdowns.forEach(dropdown => (dropdown.open = false));
 
     this.popup.active = true; // Use wa-popup's active property instead of showPopover