feat(api): chat proxy (MS22-P1i) (#615)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

apps/api/src/chat-proxy/chat-proxy.service.spec.ts

@@ -0,0 +1,107 @@
+import { ServiceUnavailableException } from "@nestjs/common";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { ChatProxyService } from "./chat-proxy.service";
+
+describe("ChatProxyService", () => {
+  const userId = "user-123";
+
+  const prisma = {
+    userAgentConfig: {
+      findUnique: vi.fn(),
+    },
+  };
+
+  const containerLifecycle = {
+    ensureRunning: vi.fn(),
+    touch: vi.fn(),
+  };
+
+  let service: ChatProxyService;
+  let fetchMock: ReturnType<typeof vi.fn>;
+
+  beforeEach(() => {
+    fetchMock = vi.fn();
+    vi.stubGlobal("fetch", fetchMock);
+    service = new ChatProxyService(prisma as never, containerLifecycle as never);
+  });
+
+  afterEach(() => {
+    vi.unstubAllGlobals();
+    vi.clearAllMocks();
+  });
+
+  describe("getContainerUrl", () => {
+    it("calls ensureRunning and touch for the user", async () => {
+      containerLifecycle.ensureRunning.mockResolvedValue({
+        url: "http://mosaic-user-user-123:19000",
+        token: "gateway-token",
+      });
+      containerLifecycle.touch.mockResolvedValue(undefined);
+
+      const url = await service.getContainerUrl(userId);
+
+      expect(url).toBe("http://mosaic-user-user-123:19000");
+      expect(containerLifecycle.ensureRunning).toHaveBeenCalledWith(userId);
+      expect(containerLifecycle.touch).toHaveBeenCalledWith(userId);
+    });
+  });
+
+  describe("proxyChat", () => {
+    it("forwards the request to the user's OpenClaw container", async () => {
+      containerLifecycle.ensureRunning.mockResolvedValue({
+        url: "http://mosaic-user-user-123:19000",
+        token: "gateway-token",
+      });
+      containerLifecycle.touch.mockResolvedValue(undefined);
+      fetchMock.mockResolvedValue(new Response("event: token\ndata: hello\n\n"));
+
+      const messages = [{ role: "user", content: "Hello from Mosaic" }];
+      const response = await service.proxyChat(userId, messages);
+
+      expect(response).toBeInstanceOf(Response);
+      expect(fetchMock).toHaveBeenCalledWith(
+        "http://mosaic-user-user-123:19000/v1/chat/completions",
+        expect.objectContaining({
+          method: "POST",
+          headers: {
+            "Content-Type": "application/json",
+          },
+        })
+      );
+
+      const [, request] = fetchMock.mock.calls[0] as [string, RequestInit];
+      const parsedBody = JSON.parse(String(request.body));
+      expect(parsedBody).toEqual({
+        messages,
+        model: "openclaw:default",
+        stream: true,
+      });
+    });
+
+    it("throws ServiceUnavailableException on connection refused errors", async () => {
+      containerLifecycle.ensureRunning.mockResolvedValue({
+        url: "http://mosaic-user-user-123:19000",
+        token: "gateway-token",
+      });
+      containerLifecycle.touch.mockResolvedValue(undefined);
+      fetchMock.mockRejectedValue(new Error("connect ECONNREFUSED 127.0.0.1:19000"));
+
+      await expect(service.proxyChat(userId, [])).rejects.toBeInstanceOf(
+        ServiceUnavailableException
+      );
+    });
+
+    it("throws ServiceUnavailableException on timeout errors", async () => {
+      containerLifecycle.ensureRunning.mockResolvedValue({
+        url: "http://mosaic-user-user-123:19000",
+        token: "gateway-token",
+      });
+      containerLifecycle.touch.mockResolvedValue(undefined);
+      fetchMock.mockRejectedValue(new Error("The operation was aborted due to timeout"));
+
+      await expect(service.proxyChat(userId, [])).rejects.toBeInstanceOf(
+        ServiceUnavailableException
+      );
+    });
+  });
+});