fix(provider): retry google rest status failures

extensions/google/video-generation-provider.test.ts

@@ -106,6 +106,7 @@ describe("google video generation provider", () => {
     generateVideosMock.mockReset();
     getVideosOperationMock.mockReset();
     createGoogleGenAIMock.mockClear();
+    vi.useRealTimers();
   });
 
   afterAll(() => {
@@ -357,6 +358,75 @@ describe("google video generation provider", () => {
     expect(result.videos[0]?.buffer).toEqual(Buffer.from("rest-video"));
   });
 
+  it("retries transient Google REST poll failures with empty bodies", async () => {
+    vi.useFakeTimers();
+    vi.spyOn(providerAuthRuntime, "resolveApiKeyForProvider").mockResolvedValue({
+      apiKey: "google-key",
+      source: "env",
+      mode: "api-key",
+    });
+    generateVideosMock.mockRejectedValue(Object.assign(new Error("sdk 404"), { status: 404 }));
+    const fetchMock = vi
+      .fn()
+      .mockResolvedValueOnce(
+        new Response(
+          JSON.stringify({
+            done: false,
+            name: "operations/rest-123",
+          }),
+        ),
+      )
+      .mockResolvedValueOnce(new Response("", { status: 503, statusText: "Service Unavailable" }))
+      .mockResolvedValueOnce(
+        new Response(
+          JSON.stringify({
+            done: true,
+            name: "operations/rest-123",
+            response: {
+              generateVideoResponse: {
+                generatedSamples: [
+                  {
+                    video: {
+                      uri: "https://generativelanguage.googleapis.com/v1beta/files/rest-video:download?alt=media",
+                      mimeType: "video/mp4",
+                    },
+                  },
+                ],
+              },
+            },
+          }),
+        ),
+      )
+      .mockResolvedValueOnce(
+        new Response("rest-video", {
+          status: 200,
+          statusText: "OK",
+          headers: { "content-type": "video/mp4" },
+        }),
+      );
+    vi.stubGlobal("fetch", fetchMock);
+
+    const provider = buildGoogleVideoGenerationProvider();
+    const resultPromise = provider.generateVideo({
+      provider: "google",
+      model: "veo-3.1-fast-generate-preview",
+      prompt: "A tiny robot watering a windowsill garden",
+      cfg: {},
+      durationSeconds: 3,
+    });
+    await vi.advanceTimersByTimeAsync(10_250);
+    const result = await resultPromise;
+
+    expect(fetchMock).toHaveBeenCalledTimes(4);
+    expect(fetchInputUrl(fetchMock, 1)).toBe(
+      "https://generativelanguage.googleapis.com/v1beta/operations/rest-123",
+    );
+    expect(fetchInputUrl(fetchMock, 2)).toBe(
+      "https://generativelanguage.googleapis.com/v1beta/operations/rest-123",
+    );
+    expect(result.videos[0]?.buffer).toEqual(Buffer.from("rest-video"));
+  });
+
   it("does not fall back to REST when SDK video generation with reference inputs returns 404", async () => {
     vi.spyOn(providerAuthRuntime, "resolveApiKeyForProvider").mockResolvedValue({
       apiKey: "google-key",

extensions/google/video-generation-provider.ts

@@ -300,6 +300,25 @@ async function requestGoogleVideoJson(params: {
   stage: "create" | "poll";
   body?: unknown;
 }): Promise<unknown> {
+  function createHttpError(response: Response, detail: unknown): Error {
+    const parts = [`HTTP ${response.status}`];
+    const statusText = response.statusText.trim();
+    if (statusText) {
+      parts.push(statusText);
+    }
+    if (typeof detail === "string") {
+      const trimmed = detail.trim();
+      if (trimmed) {
+        parts.push(trimmed);
+      }
+    } else if (detail && typeof detail === "object") {
+      parts.push(JSON.stringify(detail));
+    }
+    const error = new Error(parts.join(": "));
+    Object.assign(error, { status: response.status, statusCode: response.status });
+    return error;
+  }
+
   return await executeProviderOperationWithRetry({
     provider: "google",
     stage: params.stage,
@@ -328,12 +347,18 @@ async function requestGoogleVideoJson(params: {
         });
         try {
           const text = await response.text();
-          const payload = text ? (JSON.parse(text) as unknown) : {};
           if (!response.ok) {
-            throw new Error(
-              typeof payload === "string" ? payload : JSON.stringify(payload ?? null),
-            );
+            let detail: unknown = text;
+            if (text) {
+              try {
+                detail = JSON.parse(text) as unknown;
+              } catch {
+                detail = text;
+              }
+            }
+            throw createHttpError(response, detail);
           }
+          const payload = text ? (JSON.parse(text) as unknown) : {};
           return payload;
         } finally {
           await release();