feat(server): wire Discord DM pairing notifications

tests/notifications.test.ts

@@ -0,0 +1,107 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+
+import {
+  createDiscordNotificationService,
+  formatPairingMessage,
+  type DiscordFetch
+} from "../plugin/notifications/discord.js";
+
+const request = {
+  identifier: "client-a",
+  pairingCode: "PAIR-1234-CODE",
+  expiresAt: 1_710_000_300,
+  ttlSeconds: 300,
+  createdAt: 1_710_000_000
+};
+
+afterEach(() => {
+  vi.restoreAllMocks();
+});
+
+describe("Discord notification service", () => {
+  it("formats pairing requests as a DM-friendly message", () => {
+    const message = formatPairingMessage(request);
+
+    expect(message).toContain("Yonexus Pairing Request");
+    expect(message).toContain("`client-a`");
+    expect(message).toContain("`PAIR-1234-CODE`");
+    expect(message).toContain("TTL:** 300 seconds");
+  });
+
+  it("creates a DM channel and posts the pairing message", async () => {
+    const fetcher = vi
+      .fn<DiscordFetch>()
+      .mockResolvedValueOnce({
+        ok: true,
+        status: 200,
+        json: async () => ({ id: "dm-channel-1" })
+      })
+      .mockResolvedValueOnce({
+        ok: true,
+        status: 200,
+        json: async () => ({ id: "message-1" })
+      });
+
+    const service = createDiscordNotificationService(
+      {
+        botToken: "discord-bot-token",
+        adminUserId: "123456789012345678"
+      },
+      { fetcher }
+    );
+
+    await expect(service.sendPairingNotification(request)).resolves.toBe(true);
+    expect(fetcher).toHaveBeenCalledTimes(2);
+    expect(fetcher).toHaveBeenNthCalledWith(
+      1,
+      "https://discord.com/api/v10/users/@me/channels",
+      expect.objectContaining({
+        method: "POST",
+        headers: expect.objectContaining({
+          Authorization: "Bot discord-bot-token"
+        }),
+        body: JSON.stringify({ recipient_id: "123456789012345678" })
+      })
+    );
+    expect(fetcher).toHaveBeenNthCalledWith(
+      2,
+      "https://discord.com/api/v10/channels/dm-channel-1/messages",
+      expect.objectContaining({
+        method: "POST"
+      })
+    );
+  });
+
+  it("returns false when Discord rejects DM channel creation", async () => {
+    const fetcher = vi.fn<DiscordFetch>().mockResolvedValueOnce({
+      ok: false,
+      status: 403,
+      json: async () => ({ message: "Missing Access" })
+    });
+
+    const service = createDiscordNotificationService(
+      {
+        botToken: "discord-bot-token",
+        adminUserId: "123456789012345678"
+      },
+      { fetcher }
+    );
+
+    await expect(service.sendPairingNotification(request)).resolves.toBe(false);
+    expect(fetcher).toHaveBeenCalledTimes(1);
+  });
+
+  it("returns false when config is missing required Discord credentials", async () => {
+    const fetcher = vi.fn<DiscordFetch>();
+    const service = createDiscordNotificationService(
+      {
+        botToken: "",
+        adminUserId: ""
+      },
+      { fetcher }
+    );
+
+    await expect(service.sendPairingNotification(request)).resolves.toBe(false);
+    expect(fetcher).not.toHaveBeenCalled();
+  });
+});

tests/runtime-flow.test.ts

@@ -98,8 +98,27 @@ function createMockTransport() {
   };
 }
 
+function stubDiscordFetchSuccess() {
+  vi.stubGlobal(
+    "fetch",
+    vi
+      .fn()
+      .mockResolvedValueOnce({
+        ok: true,
+        status: 200,
+        json: async () => ({ id: "dm-channel-1" })
+      })
+      .mockResolvedValueOnce({
+        ok: true,
+        status: 200,
+        json: async () => ({ id: "message-1" })
+      })
+  );
+}
+
 describe("Yonexus.Server runtime flow", () => {
   it("runs hello -> pair_request for an unpaired client", async () => {
+    stubDiscordFetchSuccess();
     const store = createMockStore();
     const transportState = createMockTransport();
     const runtime = createYonexusServerRuntime({
@@ -160,6 +179,7 @@ describe("Yonexus.Server runtime flow", () => {
   });
 
   it("completes pair_confirm -> auth_request -> heartbeat for a client", async () => {
+    stubDiscordFetchSuccess();
     let now = 1_710_000_000;
     const keyPair = await generateKeyPair();
     const store = createMockStore();