feat(cc-form-control-element): add form getter

Fixes #1206

Author: pdesoyres-cc

src/lib/form/cc-form-control-element.abstract.js

@@ -229,6 +229,13 @@ export class CcFormControlElement extends LitElement {
     }
   }
 
+  /**
+   * @return {HTMLFormElement|null}
+   */
+  get form() {
+    return this._internals.form;
+  }
+
   /* endregion */
 
   /* region mimic the native validation API */

test/form/cc-form-control-element.abstract.test.js

@@ -610,4 +610,16 @@ describe('InputElement', () => {
 
     expect(formControlElement.value).to.eql('reset value');
   });
+
+  it('should have the right form element', async () => {
+    const customElement = getCustomElement();
+
+    /** @type {HTMLFormElement} */
+    const formElement = await getElement(
+      `<form><${customElement} name="input" value="current value"></${customElement}></form>`,
+    );
+    const formControlElement = formElement.querySelector(customElement);
+
+    expect(formControlElement.form).to.eql(formElement);
+  });
 });