feat(select): add required prop (#30155)

Issue number: resolves internal

---------

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## What is the current behavior?
- Currently, the screen reader do not announce the component as required
when `required={true}`.

## What is the new behavior?
- Added a new `required` prop to be used for accessibility purposes that
adds the `aria-required` attribute to select's inner native button.

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

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## Other information

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screenshots of how the component looks before and after the change. -->

core/src/components/select/select.tsx

@@ -196,6 +196,13 @@ export class Select implements ComponentInterface {
    */
   @Prop({ mutable: true }) value?: any | null;
 
+  /**
+   * If true, screen readers will announce it as a required field. This property
+   * works only for accessibility purposes, it will not prevent the form from
+   * submitting if the value is invalid.
+   */
+  @Prop() required = false;
+
   /**
    * Emitted when the value has changed.
    *
@@ -974,7 +981,7 @@ export class Select implements ComponentInterface {
   }
 
   private renderListbox() {
-    const { disabled, inputId, isExpanded } = this;
+    const { disabled, inputId, isExpanded, required } = this;
 
     return (
       <button
@@ -983,6 +990,7 @@ export class Select implements ComponentInterface {
         aria-label={this.ariaLabel}
         aria-haspopup="dialog"
         aria-expanded={`${isExpanded}`}
+        aria-required={`${required}`}
         onFocus={this.onFocus}
         onBlur={this.onBlur}
         ref={(focusEl) => (this.focusEl = focusEl)}

core/src/components/select/test/select.spec.tsx

@@ -125,3 +125,35 @@ describe('select: slot interactivity', () => {
     expect(divSpy).toHaveBeenCalled();
   });
 });
+
+describe('ion-select: required', () => {
+  it('should have a aria-required attribute as true in inner button', async () => {
+    const page = await newSpecPage({
+      components: [Select],
+      html: `
+        <ion-select required="true"></ion-select>
+      `,
+    });
+
+    const select = page.body.querySelector('ion-select')!;
+
+    const nativeButton = select.shadowRoot!.querySelector('button')!;
+
+    expect(nativeButton.getAttribute('aria-required')).toBe('true');
+  });
+
+  it('should not have a aria-required attribute as false in inner button', async () => {
+    const page = await newSpecPage({
+      components: [Select],
+      html: `
+        <ion-select required="false"></ion-select>
+      `,
+    });
+
+    const select = page.body.querySelector('ion-select')!;
+
+    const nativeButton = select.shadowRoot!.querySelector('button')!;
+
+    expect(nativeButton.getAttribute('aria-required')).toBe('false');
+  });
+});