feat(redis): add channel prefix and error handling

test/event-target-redis.test.ts

@@ -394,6 +394,169 @@ describe("createRedisEventTarget", () => {
     });
   });
 
+  describe("channel prefix", () => {
+    it("publishes to prefixed channel when prefix is set", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+        prefix: "alk:events:",
+      });
+
+      const event = new CustomEvent("call.responded:uuid-123", {
+        detail: { type: "call.responded", id: "uuid-123", payload: { status: "ok" } },
+      }) as TestEvent;
+
+      eventTarget.dispatchEvent(event);
+
+      expect(publishClient.publish).toHaveBeenCalledWith(
+        "alk:events:call.responded:uuid-123",
+        expect.any(String),
+      );
+    });
+
+    it("subscribes to prefixed channel when prefix is set", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+        prefix: "alk:events:",
+      });
+
+      const listener = vi.fn();
+      eventTarget.addEventListener("call.responded:uuid-123", listener);
+
+      expect(subscribeClient.subscribe).toHaveBeenCalledWith("alk:events:call.responded:uuid-123");
+    });
+
+    it("unsubscribes from prefixed channel when prefix is set", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+        prefix: "alk:events:",
+      });
+
+      const listener = vi.fn();
+      eventTarget.addEventListener("call.responded:uuid-123", listener);
+      eventTarget.removeEventListener("call.responded:uuid-123", listener);
+
+      expect(subscribeClient.unsubscribe).toHaveBeenCalledWith("alk:events:call.responded:uuid-123");
+    });
+
+    it("delivers messages on prefixed channels to listeners", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+        prefix: "alk:events:",
+      });
+
+      const listener = vi.fn();
+      eventTarget.addEventListener("call.responded:uuid-123", listener);
+
+      const envelope: EventEnvelope = {
+        type: "call.responded",
+        id: "uuid-123",
+        payload: { status: "ok" },
+      };
+      subscribeClient.simulateMessage("alk:events:call.responded:uuid-123", JSON.stringify(envelope));
+
+      expect(listener).toHaveBeenCalledTimes(1);
+      expect((listener.mock.calls[0][0] as TestEvent).detail).toEqual(envelope);
+    });
+
+    it("ignores messages on non-prefixed channels when prefix is set", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+        prefix: "alk:events:",
+      });
+
+      const listener = vi.fn();
+      eventTarget.addEventListener("call.responded:uuid-123", listener);
+
+      subscribeClient.simulateMessage("call.responded:uuid-123", JSON.stringify({ type: "call.responded", id: "uuid-123", payload: null }));
+
+      expect(listener).not.toHaveBeenCalled();
+    });
+
+    it("defaults prefix to empty string", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+      });
+
+      const event = new CustomEvent("test:1", {
+        detail: { type: "test", id: "1", payload: null },
+      }) as TestEvent;
+
+      eventTarget.dispatchEvent(event);
+
+      expect(publishClient.publish).toHaveBeenCalledWith("test:1", expect.any(String));
+    });
+  });
+
+  describe("error handling", () => {
+    it("skips messages that fail to parse and logs a warning", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+      });
+
+      const listener = vi.fn();
+      eventTarget.addEventListener("topic:a", listener);
+
+      const warnSpy = vi.spyOn(console, "warn").mockImplementation(() => {});
+
+      subscribeClient.simulateMessage("topic:a", "not valid json{{");
+
+      expect(listener).not.toHaveBeenCalled();
+      expect(warnSpy).toHaveBeenCalledTimes(1);
+      expect(warnSpy).toHaveBeenCalledWith(
+        'Failed to parse message on channel "topic:a": not valid json{{',
+      );
+
+      warnSpy.mockRestore();
+    });
+
+    it("continues delivering valid messages after a parse error", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+      });
+
+      const listener = vi.fn();
+      eventTarget.addEventListener("topic:a", listener);
+
+      const warnSpy = vi.spyOn(console, "warn").mockImplementation(() => {});
+
+      subscribeClient.simulateMessage("topic:a", "broken{{{");
+
+      expect(listener).not.toHaveBeenCalled();
+
+      const envelope: EventEnvelope = { type: "topic", id: "a", payload: "good" };
+      subscribeClient.simulateMessage("topic:a", JSON.stringify(envelope));
+
+      expect(listener).toHaveBeenCalledTimes(1);
+      expect((listener.mock.calls[0][0] as TestEvent).detail).toEqual(envelope);
+
+      warnSpy.mockRestore();
+    });
+  });
+
   describe("EventListenerObject support", () => {
     it("addEventListener accepts EventListenerObject with handleEvent", () => {
       const publishClient = createMockRedis();