chore(button): re-add and test 'type=reset' feature with native form

packages/button/src/LionButton.js

@@ -188,9 +188,10 @@ export class LionButton extends DisabledWithTabIndexMixin(SlotMixin(LitElement))
       e.stopPropagation();
     }
 
-    if (this.type === 'submit' && e.target === this) {
+    if ((this.type === 'submit' || this.type === 'reset') && e.target === this) {
       if (this._form) {
         const nativeButton = document.createElement('button');
+        nativeButton.type = this.type;
         this._form.appendChild(nativeButton);
         nativeButton.click();
         this._form.removeChild(nativeButton);

packages/button/stories/index.stories.js

@@ -54,6 +54,9 @@ storiesOf('Buttons|Button', module)
         <li>
           Submit on button click
         </li>
+        <li>
+          Reset native form fields when using type="reset"
+        </li>
         <li>
           Submit on button enter or space keypress
         </li>

packages/button/test/lion-button.test.js

@@ -270,6 +270,29 @@ describe('lion-button', () => {
         expect(formSubmitSpy.callCount).to.equal(1);
       });
 
+      it('supports resetting form inputs in a native form', async () => {
+        const form = await fixture(html`
+          <form>
+            <input name="firstName" />
+            <input name="lastName" />
+            <lion-button type="reset">reset</lion-button>
+          </form>
+        `);
+        const btn = form.querySelector('lion-button');
+        const firstName = form.querySelector('input[name=firstName]');
+        const lastName = form.querySelector('input[name=lastName]');
+        firstName.value = 'Foo';
+        lastName.value = 'Bar';
+
+        expect(firstName.value).to.equal('Foo');
+        expect(lastName.value).to.equal('Bar');
+
+        btn.click();
+
+        expect(firstName.value).to.be.empty;
+        expect(lastName.value).to.be.empty;
+      });
+
       // input "enter" keypress mock doesn't seem to work right now, but should be tested in the future (maybe with Selenium)
       it.skip('works with implicit form submission on-enter inside an input', async () => {
         const formSubmitSpy = sinon.spy(e => e.preventDefault());