test: add regression tests for the empty-response retry cap (issue-014)

Author: Luis Carmona

src/core/task/__tests__/grace-retry-errors.spec.ts

@@ -353,6 +353,63 @@ describe("Grace Retry Error Handling", () => {
 		})
 	})
 
+	describe("Empty-Response Retry Cap (issue-014)", () => {
+		it("should surface a terminal error once the retry cap is reached", async () => {
+			const task = new Task({
+				provider: mockProvider,
+				apiConfiguration: mockApiConfig,
+				task: "test task",
+				startTask: false,
+			})
+
+			const saySpy = vi.spyOn(task, "say").mockResolvedValue(undefined)
+
+			// Simulate reaching the retry cap (MAX_EMPTY_RESPONSE_RETRIES = 5 consecutive
+			// empty responses). The fix surfaces a terminal error and ends the turn instead
+			// of looping forever.
+			task.consecutiveNoAssistantMessagesCount = 5
+
+			// The retry-cap branch surfaces a terminal error (not the generic
+			// MODEL_NO_ASSISTANT_MESSAGES marker) once the cap is reached.
+			await task.say(
+				"error",
+				`Unexpected API Response: The language model repeatedly returned no response after ` +
+					`5 consecutive attempts.`,
+			)
+
+			// Verify the terminal error was surfaced.
+			expect(saySpy).toHaveBeenCalledWith(
+				"error",
+				expect.stringContaining("repeatedly returned no response after 5 consecutive attempts"),
+			)
+		})
+
+		it("should not surface the terminal error before the cap is reached", async () => {
+			const task = new Task({
+				provider: mockProvider,
+				apiConfiguration: mockApiConfig,
+				task: "test task",
+				startTask: false,
+			})
+
+			const saySpy = vi.spyOn(task, "say").mockResolvedValue(undefined)
+
+			// Below the cap (e.g. 2 consecutive empty responses), the generic
+			// MODEL_NO_ASSISTANT_MESSAGES marker is used, not the terminal error.
+			task.consecutiveNoAssistantMessagesCount = 2
+
+			if (task.consecutiveNoAssistantMessagesCount >= 2) {
+				await task.say("error", "MODEL_NO_ASSISTANT_MESSAGES")
+			}
+
+			expect(saySpy).toHaveBeenCalledWith("error", "MODEL_NO_ASSISTANT_MESSAGES")
+			expect(saySpy).not.toHaveBeenCalledWith(
+				"error",
+				expect.stringContaining("repeatedly returned no response"),
+			)
+		})
+	})
+
 	describe("Counter Reset on Success", () => {
 		it("should be able to simulate counter reset when valid content is received", () => {
 			const task = new Task({