Wake Render backend before embedded login

frontend/components/XamanLoginPanel.tsx

@@ -266,6 +266,7 @@ function retryAfterMilliseconds(response: Response): number {
 }
 
 type LoginStartRetryReason = "rate-limited" | "temporarily-unavailable";
+type EmbeddedLoginPreparationPhase = LoginStartRetryReason | "waking-up";
 
 export async function startLoginWithRetry(
   signal: AbortSignal,
@@ -319,6 +320,22 @@ export async function startLoginWithRetry(
   throw new BackendRequestTimeoutError();
 }
 
+export async function prepareEmbeddedLogin(
+  signal: AbortSignal,
+  onProgress: (phase: EmbeddedLoginPreparationPhase) => void,
+  retryWindowMs = EMBEDDED_LOGIN_START_RETRY_WINDOW_MS
+): Promise<LoginStartResponse> {
+  // A GET readiness probe reliably wakes a spun-down Render Free backend.
+  // Sending login/start as the first request can be rejected by Render's edge
+  // with 429 responses before the Python service has started.
+  if (signal.aborted) {
+    throw signal.reason ?? new Error("Login cancelled");
+  }
+  onProgress("waking-up");
+  await waitForBackendReady(BACKEND_BASE_URL, signal);
+  return startLoginWithRetry(signal, onProgress, retryWindowMs);
+}
+
 export function XamanLoginPanel() {
   const [isLoading, setIsLoading] = useState(false);
   const [isLoggingOut, setIsLoggingOut] = useState(false);
@@ -601,11 +618,13 @@ export function XamanLoginPanel() {
       );
 
       try {
-        const data = await startLoginWithRetry(
+        const data = await prepareEmbeddedLogin(
           controller.signal,
           (reason) => {
             const message =
-              reason === "rate-limited"
+              reason === "waking-up"
+                ? "Xaman is ready. Starting the secure CalorieApp service. This can take about a minute. Keep this page open."
+                : reason === "rate-limited"
                 ? "Xaman is ready. CalorieApp is temporarily busy and will retry automatically. Keep this page open."
                 : "Xaman is ready. CalorieApp is still starting and will retry automatically. Keep this page open.";
             setLoginStatus(message);

tools/tests/xaman_login_start_retry.test.mjs

@@ -118,3 +118,167 @@ test("login start retries transport errors and transient responses", async () =>
   ]);
   assert.equal(result.state, "state-abcdefghijklmnopqrstuvwxyz-0123456789");
 });
+
+test("embedded login wakes the backend before creating login state", async () => {
+  const typescript = requireFromFrontend("typescript");
+  const source = await readFile(COMPONENT_PATH, "utf8");
+  const compiled = typescript.transpileModule(source, {
+    compilerOptions: {
+      jsx: typescript.JsxEmit.ReactJSX,
+      module: typescript.ModuleKind.CommonJS,
+      target: typescript.ScriptTarget.ES2022,
+    },
+  }).outputText;
+
+  const events = [];
+  const loginResponse = {
+    ok: true,
+    status: 200,
+    headers: { get: () => null },
+    json: async () => ({
+      state: "state-abcdefghijklmnopqrstuvwxyz-0123456789",
+      expires_at: "2099-01-01T00:00:00Z",
+      wordpress_signin_url: "https://calorietoken.net/?xl-signin=1",
+      browser_handoff_token: "token-abcdefghijklmnopqrstuvwxyz-0123456789",
+    }),
+  };
+
+  class TestBackendRequestTimeoutError extends Error {}
+  const module = { exports: {} };
+  const context = vm.createContext({
+    AbortController,
+    Error,
+    Math,
+    Number,
+    Promise,
+    URL,
+    clearImmediate,
+    console,
+    module,
+    exports: module.exports,
+    process: { env: {} },
+    require(specifier) {
+      if (specifier === "react") {
+        return {};
+      }
+      if (specifier === "react/jsx-runtime") {
+        return { Fragment: Symbol("Fragment"), jsx() {}, jsxs() {} };
+      }
+      if (specifier === "@/components/authEvents") {
+        return { announceAuthState() {} };
+      }
+      if (specifier === "@/lib/backendRequest") {
+        return {
+          backendRequest: async () => {
+            events.push("login-start");
+            return loginResponse;
+          },
+          backendUnavailableMessage: (_error, fallback) => fallback,
+          BackendRequestTimeoutError: TestBackendRequestTimeoutError,
+          waitForBackendReady: async () => {
+            events.push("backend-ready");
+          },
+        };
+      }
+      throw new Error(`Unexpected require: ${specifier}`);
+    },
+    setImmediate,
+    window: {
+      clearTimeout(timer) {
+        clearImmediate(timer);
+      },
+      setTimeout(callback) {
+        return setImmediate(callback);
+      },
+    },
+  });
+
+  vm.runInContext(compiled, context);
+  const phases = [];
+  const result = await module.exports.prepareEmbeddedLogin(
+    new AbortController().signal,
+    (phase) => phases.push(phase),
+    10_000
+  );
+
+  assert.deepEqual(events, ["backend-ready", "login-start"]);
+  assert.deepEqual(phases, ["waking-up"]);
+  assert.equal(result.state, "state-abcdefghijklmnopqrstuvwxyz-0123456789");
+});
+
+test("embedded login does not report progress after cancellation", async () => {
+  const typescript = requireFromFrontend("typescript");
+  const source = await readFile(COMPONENT_PATH, "utf8");
+  const compiled = typescript.transpileModule(source, {
+    compilerOptions: {
+      jsx: typescript.JsxEmit.ReactJSX,
+      module: typescript.ModuleKind.CommonJS,
+      target: typescript.ScriptTarget.ES2022,
+    },
+  }).outputText;
+
+  const events = [];
+  class TestBackendRequestTimeoutError extends Error {}
+  const module = { exports: {} };
+  const context = vm.createContext({
+    AbortController,
+    Error,
+    Math,
+    Number,
+    Promise,
+    URL,
+    clearImmediate,
+    console,
+    module,
+    exports: module.exports,
+    process: { env: {} },
+    require(specifier) {
+      if (specifier === "react") {
+        return {};
+      }
+      if (specifier === "react/jsx-runtime") {
+        return { Fragment: Symbol("Fragment"), jsx() {}, jsxs() {} };
+      }
+      if (specifier === "@/components/authEvents") {
+        return { announceAuthState() {} };
+      }
+      if (specifier === "@/lib/backendRequest") {
+        return {
+          backendRequest: async () => {
+            events.push("login-start");
+          },
+          backendUnavailableMessage: (_error, fallback) => fallback,
+          BackendRequestTimeoutError: TestBackendRequestTimeoutError,
+          waitForBackendReady: async () => {
+            events.push("backend-ready");
+          },
+        };
+      }
+      throw new Error(`Unexpected require: ${specifier}`);
+    },
+    setImmediate,
+    window: {
+      clearTimeout(timer) {
+        clearImmediate(timer);
+      },
+      setTimeout(callback) {
+        return setImmediate(callback);
+      },
+    },
+  });
+
+  vm.runInContext(compiled, context);
+  const controller = new AbortController();
+  const abortReason = new Error("cancelled before login");
+  controller.abort(abortReason);
+
+  await assert.rejects(
+    module.exports.prepareEmbeddedLogin(
+      controller.signal,
+      (phase) => events.push(phase),
+      10_000
+    ),
+    abortReason
+  );
+  assert.deepEqual(events, []);
+});