new_pull

packages/ai/test/provider-error-body-regression.test.ts

@@ -186,4 +186,28 @@ describe("provider error body passthrough (per-tier regression)", () => {
 		expect(output.errorMessage).toContain("blocked by gateway WAF");
 		expect(output.errorMessage).not.toContain("Unknown: UnknownError");
 	});
+
+	it("bedrock preserves the SDK validation message when the response body is a stream", async () => {
+		bedrockMock.sendError = Object.assign(
+			new Error(
+				"Invocation of model ID anthropic.claude-opus-5 with on-demand throughput isn't supported. Retry with an inference profile.",
+			),
+			{
+				name: "ValidationException",
+				$metadata: { httpStatusCode: 400 },
+				$response: {
+					statusCode: 400,
+					body: { pipe: () => undefined, _readableState: { buffer: [], length: 0 } },
+				},
+			},
+		);
+
+		const model = getModel("amazon-bedrock", "global.anthropic.claude-opus-5");
+		const output = await drainResult(streamSimpleBedrock(model, { messages: context.messages }, {}));
+
+		expect(output.stopReason).toBe("error");
+		expect(output.errorMessage).toContain("on-demand throughput isn't supported");
+		expect(output.errorMessage).toContain("inference profile");
+		expect(output.errorMessage).not.toContain("_readableState");
+	});
 });