fix(providers): add safe json response helper

src/agents/provider-http-errors.test.ts

@@ -4,6 +4,7 @@ import {
   assertOkOrThrowHttpError,
   extractProviderErrorDetail,
   extractProviderRequestId,
+  readProviderJsonResponse,
 } from "./provider-http-errors.js";
 
 describe("provider error utils", () => {
@@ -54,4 +55,15 @@ describe("provider error utils", () => {
       "Legacy provider error (HTTP 400): Bad request [code=invalid_request] [request_id=req_legacy]",
     );
   });
+
+  it("wraps malformed successful JSON responses with provider labels", async () => {
+    const response = new Response("{ nope", {
+      status: 200,
+      headers: { "content-type": "application/json" },
+    });
+
+    await expect(readProviderJsonResponse(response, "Provider catalog failed")).rejects.toThrow(
+      "Provider catalog failed: malformed JSON response",
+    );
+  });
 });

src/agents/provider-http-errors.ts

@@ -163,3 +163,11 @@ export async function assertOkOrThrowHttpError(response: Response, label: string
   }
   throw await createProviderHttpError(response, label, { statusPrefix: "HTTP " });
 }
+
+export async function readProviderJsonResponse<T>(response: Response, label: string): Promise<T> {
+  try {
+    return (await response.json()) as T;
+  } catch (cause) {
+    throw new Error(`${label}: malformed JSON response`, { cause });
+  }
+}

src/plugin-sdk/provider-http.ts

@@ -9,6 +9,7 @@ export {
   extractProviderRequestId,
   formatProviderErrorPayload,
   formatProviderHttpErrorMessage,
+  readProviderJsonResponse,
   readResponseTextLimited,
   truncateErrorDetail,
 } from "../agents/provider-http-errors.js";