fix(www): reset the contact view if the user navigates back (#1737)

* Reset the contact view when a user clicks the "back" button.

* Add a test case.

* Use strict equality.

src/www/ui_components/app-root.js

@@ -801,6 +801,11 @@ export class AppRoot extends mixinBehaviors([AppLocalizeBehavior], PolymerElemen
   }
 
   _goBack() {
+    if (this.page === 'contact') {
+      // TODO: Replace with `this.$.contactView` once the element is no longer inside a `dom-if`.
+      this.shadowRoot.querySelector('#contactView').reset();
+    }
+
     // If there is a navigation on the webview's history stack, pop it off to go back.
     if (history.length > 1) {
       history.back();

src/www/views/contact_view/index.spec.ts

@@ -60,6 +60,18 @@ describe('ContactView client variant', () => {
     expect(exitCard.textContent).toContain('experiencing high support volume');
   });
 
+  it('resets the view on `reset()`', async () => {
+    const radioButton = el.shadowRoot!.querySelectorAll('mwc-formfield mwc-radio')[0] as HTMLElement;
+    radioButton.click();
+    await nextFrame();
+
+    el.reset();
+    await nextFrame();
+
+    const exitCard = el.shadowRoot!.querySelector('outline-card')!;
+    expect(exitCard).toBeNull();
+  });
+
   describe('when the user selects that they have no open tickets', () => {
     let issueSelector: Select;
 

src/www/views/contact_view/index.ts

@@ -161,7 +161,7 @@ export class ContactView extends LitElement {
     this.step = Step.FORM;
   }
 
-  private reset() {
+  reset() {
     this.isFormSubmitting = false;
     this.showIssueSelector = false;
     this.step = Step.ISSUE_WIZARD;