frontend: fix rendering when backend not available yet (#2448)

- don't wait for languages to be ready to render UI, as this can result
in empty page if backend can not be reached.
- catch if /api/settings returns an invalid response to show 'backend
initializing' message
- will support initContainers where backend may return 5xx error while
backend is initializing, via #2449

Note: this results in locale picker showing all available locales if
backend is not available, not just filtered ones, but I think that's a
reasonable trade-off.

frontend/src/index.test.ts

@@ -63,7 +63,7 @@ describe("browsertrix-app", () => {
     expect(el).instanceOf(App);
   });
 
-  it("blocks render if settings aren't defined", async () => {
+  it("don't block render if settings aren't defined", async () => {
     stub(AuthService, "initSessionStorage").returns(
       Promise.resolve({
         headers: { Authorization: "_fake_headers_" },
@@ -76,7 +76,7 @@ describe("browsertrix-app", () => {
     const el = await fixture<App>(html` <browsertrix-app></browsertrix-app>`);
     await el.updateComplete;
 
-    expect(el.shadowRoot?.childElementCount).to.equal(0);
+    expect(el.shadowRoot?.childElementCount).to.not.equal(0);
   });
 
   it("renders org when authenticated", async () => {

frontend/src/index.ts

@@ -101,9 +101,6 @@ export class App extends BtrixElement {
 
   authService = new AuthService();
 
-  @state()
-  private translationReady = false;
-
   @provide({ context: viewStateContext })
   @state()
   private viewState!: ViewState;
@@ -187,6 +184,7 @@ export class App extends BtrixElement {
   }
 
   firstUpdated() {
+    void this.initTranslation();
     this.trackPageView();
   }
 
@@ -194,9 +192,6 @@ export class App extends BtrixElement {
     if (changedProperties.has("settings")) {
       AppStateService.updateSettings(this.settings || null);
 
-      if (this.settings && !changedProperties.get("settings")) {
-        void this.initTranslation();
-      }
     }
     if (changedProperties.has("viewState")) {
       this.handleViewStateChange(
@@ -234,7 +229,6 @@ export class App extends BtrixElement {
     await localize.initLanguage();
     // TODO We might want to set this in a lit-localize-status event listener
     // see https://lit.dev/docs/localization/runtime-mode/#example-of-using-the-status-event
-    this.translationReady = true;
   }
 
   getLocationPathname() {
@@ -351,8 +345,6 @@ export class App extends BtrixElement {
   }
 
   render() {
-    if (!this.translationReady) return;
-
     return html`
       <div class="min-w-screen flex min-h-screen flex-col">
         ${this.renderSuperadminBanner()} ${this.renderNavBar()}

frontend/src/pages/log-in.ts

@@ -365,15 +365,21 @@ export class LogInPage extends BtrixElement {
       return;
     }
 
-    const resp = await fetch("/api/settings");
-    if (resp.status === 200) {
-      this.formStateService.send("BACKEND_INITIALIZED");
-    } else {
-      this.formStateService.send("BACKEND_NOT_INITIALIZED");
-      this.timerId = window.setTimeout(() => {
-        void this.checkBackendInitialized();
-      }, 5000);
+    try {
+      const resp = await fetch("/api/settings");
+      if (resp.status === 200) {
+        this.formStateService.send("BACKEND_INITIALIZED");
+        return;
+      }
+    } catch (e) {
+      // assume backend not available if exception thrown
     }
+
+    // mark as not initialized
+    this.formStateService.send("BACKEND_NOT_INITIALIZED");
+    this.timerId = window.setTimeout(() => {
+      void this.checkBackendInitialized();
+    }, 5000);
   }
 
   async onSubmitLogIn(event: SubmitEvent) {