fix(listbox): teleported options compatible with map/repeat

.changeset/calm-pots-tell.md

@@ -0,0 +1,5 @@
+---
+'@lion/listbox': patch
+---
+
+teleported options compatible with map/repeat for listbox/combobox/select-rich

packages/listbox/src/ListboxMixin.js

@@ -18,6 +18,41 @@ import { LionOptions } from './LionOptions.js';
  * @typedef {import('@lion/form-core/types/FormControlMixinTypes.js').ModelValueEventDetails} ModelValueEventDetails
  */
 
+// TODO: consider adding methods below to @lion/helpers
+
+/**
+ * Sometimes, we want to provide best DX (direct slottables) and be accessible
+ * at the same time.
+ * In the first example below, we need to wrap our options in light dom in an element with
+ * [role=listbox]. We could achieve this via the second example, but it would affect our
+ * public api negatively. not allowing us to be forward compatible with the AOM spec:
+ * https://wicg.github.io/aom/explainer.html
+ * With this method, it's possible to watch elements in the default slot and move them
+ * to the desired target (the element with [role=listbox]) in light dom.
+ *
+ * @example
+ * # desired api
+ * <sel-ect>
+ *  <opt-ion></opt-ion>
+ * </sel-ect>
+ * # desired end state
+ * <sel-ect>
+ *  <div role="listbox" slot="lisbox">
+ *    <opt-ion></opt-ion>
+ *  </div>
+ * </sel-ect>
+ * @param {HTMLElement} source host of ShadowRoot with default <slot>
+ * @param {HTMLElement} target the desired target in light dom
+ */
+function moveDefaultSlottablesToTarget(source, target) {
+  Array.from(source.childNodes).forEach((/** @type {* & Element} */ c) => {
+    const isNamedSlottable = c.hasAttribute && c.hasAttribute('slot');
+    if (!isNamedSlottable) {
+      target.appendChild(c);
+    }
+  });
+}
+
 function uuid() {
   return Math.random().toString(36).substr(2, 10);
 }
@@ -821,13 +856,9 @@ const ListboxMixinImplementation = superclass =>
       );
 
       if (slot) {
-        slot.assignedNodes().forEach(node => {
-          this._listboxNode.appendChild(node);
-        });
+        moveDefaultSlottablesToTarget(this, this._listboxNode);
         slot.addEventListener('slotchange', () => {
-          slot.assignedNodes().forEach(node => {
-            this._listboxNode.appendChild(node);
-          });
+          moveDefaultSlottablesToTarget(this, this._listboxNode);
         });
       }
     }

packages/listbox/test-suites/ListboxMixin.suite.js

@@ -1,4 +1,5 @@
 import '@lion/core/differentKeyEventNamesShimIE';
+import { repeat, LitElement } from '@lion/core';
 import { Required } from '@lion/form-core';
 import { LionOptions } from '@lion/listbox';
 import '@lion/listbox/define';
@@ -24,23 +25,6 @@ function mimicKeyPress(el, key) {
   el.dispatchEvent(new KeyboardEvent('keyup', { key }));
 }
 
-// /**
-//  * @param {LionListbox} lionListboxEl
-//  */
-// function getProtectedMembers(lionListboxEl) {
-//   // @ts-ignore protected members allowed in test
-//   const {
-//     _inputNode: input,
-//     _activeDescendantOwnerNode: activeDescendantOwner,
-//     _listboxNode: listbox,
-//   } = lionListboxEl;
-//   return {
-//     input,
-//     activeDescendantOwner,
-//     listbox,
-//   };
-// }
-
 /**
  * @param { {tagString?:string, optionTagString?:string} } [customConfig]
  */
@@ -1384,5 +1368,96 @@ export function runListboxMixinSuite(customConfig = {}) {
         expect(clickSpy).to.not.have.been.called;
       });
     });
+
+    describe('Dynamically adding options', () => {
+      class MyEl extends LitElement {
+        constructor() {
+          super();
+          /** @type {string[]} */
+          this.options = ['option 1', 'option 2'];
+        }
+
+        clearOptions() {
+          /** @type {string[]} */
+          this.options = [];
+          this.requestUpdate();
+        }
+
+        addOption() {
+          this.options.push(`option ${this.options.length + 1}`);
+          this.requestUpdate();
+        }
+
+        get withMap() {
+          return /** @type {LionListbox} */ (this.shadowRoot?.querySelector('#withMap'));
+        }
+
+        get withRepeat() {
+          return /** @type {LionListbox} */ (this.shadowRoot?.querySelector('#withRepeat'));
+        }
+
+        get registrationComplete() {
+          return Promise.all([
+            this.withMap.registrationComplete,
+            this.withRepeat.registrationComplete,
+          ]);
+        }
+
+        render() {
+          return html`
+            <${tag} id="withMap">
+              ${this.options.map(
+                option => html` <lion-option .choiceValue="${option}">${option}</lion-option> `,
+              )}
+            </${tag}>
+            <${tag} id="withRepeat">
+              ${repeat(
+                this.options,
+                option => option,
+                option => html` <lion-option .choiceValue="${option}">${option}</lion-option> `,
+              )}
+            </${tag}>
+          `;
+        }
+      }
+
+      customElements.define('my-el', MyEl);
+
+      it('works with array map and repeat directive', async () => {
+        const choiceVals = (/** @type {LionListbox} */ elm) =>
+          elm.formElements.map(fel => fel.choiceValue);
+        const insideListboxNode = (/** @type {LionListbox} */ elm) =>
+          // @ts-ignore [allow-protected] in test
+          elm.formElements.filter(fel => elm._listboxNode.contains(fel)).length ===
+          elm.formElements.length;
+
+        const el = /** @type {MyEl} */ (await _fixture(html`<my-el></my-el>`));
+
+        expect(choiceVals(el.withMap)).to.eql(el.options);
+        expect(el.withMap.formElements.length).to.equal(2);
+        expect(insideListboxNode(el.withMap)).to.be.true;
+        expect(choiceVals(el.withRepeat)).to.eql(el.options);
+        expect(el.withRepeat.formElements.length).to.equal(2);
+        expect(insideListboxNode(el.withRepeat)).to.be.true;
+
+        el.addOption();
+        await el.updateComplete;
+        expect(choiceVals(el.withMap)).to.eql(el.options);
+        expect(el.withMap.formElements.length).to.equal(3);
+        expect(insideListboxNode(el.withMap)).to.be.true;
+        expect(choiceVals(el.withRepeat)).to.eql(el.options);
+        expect(el.withRepeat.formElements.length).to.equal(3);
+        expect(insideListboxNode(el.withRepeat)).to.be.true;
+
+        el.clearOptions();
+        await el.updateComplete;
+        expect(choiceVals(el.withMap)).to.eql(el.options);
+        expect(el.withMap.formElements.length).to.equal(0);
+        expect(insideListboxNode(el.withMap)).to.be.true;
+        expect(choiceVals(el.withRepeat)).to.eql(el.options);
+        expect(el.withRepeat.formElements.length).to.equal(0);
+        expect(insideListboxNode(el.withRepeat)).to.be.true;
+      });
+    });
   });
 }