Deduplicate referral invite emails

Author: phucnguyen1707

src/app/api/referrals/route.dedupe.test.ts

@@ -0,0 +1,119 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { NextRequest } from "next/server";
+import { POST } from "./route";
+
+const mocks = vi.hoisted(() => ({
+  mockGetAuthContext: vi.fn(),
+  mockCreateServiceClient: vi.fn(),
+  mockReferralInviteEmail: vi.fn(),
+  mockSendEmail: vi.fn(),
+}));
+
+vi.mock("@/lib/auth/get-user", () => ({
+  getAuthContext: mocks.mockGetAuthContext,
+}));
+
+vi.mock("@/lib/supabase/service", () => ({
+  createServiceClient: mocks.mockCreateServiceClient,
+}));
+
+vi.mock("@/lib/email", () => ({
+  referralInviteEmail: mocks.mockReferralInviteEmail,
+  sendEmail: mocks.mockSendEmail,
+}));
+
+function makePostRequest(body: Record<string, unknown>) {
+  return new NextRequest("http://localhost/api/referrals", {
+    method: "POST",
+    body: JSON.stringify(body),
+    headers: { "Content-Type": "application/json" },
+  });
+}
+
+describe("POST /api/referrals duplicate invite handling", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    mocks.mockReferralInviteEmail.mockReturnValue({
+      subject: "Join ugig.net",
+      html: "<p>Join</p>",
+      text: "Join",
+    });
+    mocks.mockSendEmail.mockResolvedValue({ success: true });
+  });
+
+  it("deduplicates repeated emails within the same invite request", async () => {
+    const existingInviteLookup = vi.fn().mockResolvedValue({ data: [], error: null });
+    const serviceClient = {
+      from: vi.fn(() => ({
+        select: vi.fn(() => ({
+          eq: vi.fn(() => ({
+            gte: vi.fn().mockResolvedValue({ count: 0, error: null }),
+            in: existingInviteLookup,
+          })),
+        })),
+      })),
+    };
+    mocks.mockCreateServiceClient.mockReturnValue(serviceClient);
+
+    const insertReferrals = vi.fn().mockReturnValue({
+      select: vi.fn().mockResolvedValue({
+        data: [{ id: "ref1", referred_email: "friend@test.com", status: "pending" }],
+        error: null,
+      }),
+    });
+    const authSupabase = {
+      from: vi.fn((table: string) => {
+        if (table === "profiles") {
+          return {
+            select: vi.fn(() => ({
+              eq: vi.fn(() => ({
+                single: vi.fn().mockResolvedValue({
+                  data: {
+                    referral_code: "testuser",
+                    username: "testuser",
+                    full_name: "Test User",
+                  },
+                  error: null,
+                }),
+              })),
+            })),
+          };
+        }
+
+        if (table === "referrals") {
+          return { insert: insertReferrals };
+        }
+
+        return {};
+      }),
+    };
+    mocks.mockGetAuthContext.mockResolvedValue({
+      user: { id: "user1" },
+      supabase: authSupabase,
+    });
+
+    const res = await POST(
+      makePostRequest({
+        emails: [" Friend@Test.com ", "friend@test.com", "FRIEND@test.com"],
+      })
+    );
+
+    expect(res.status).toBe(200);
+    expect(existingInviteLookup).toHaveBeenCalledWith("referred_email", ["friend@test.com"]);
+    expect(mocks.mockSendEmail).toHaveBeenCalledTimes(1);
+    expect(mocks.mockSendEmail).toHaveBeenCalledWith({
+      to: "friend@test.com",
+      subject: "Join ugig.net",
+      html: "<p>Join</p>",
+      text: "Join",
+    });
+    expect(insertReferrals).toHaveBeenCalledWith([
+      {
+        referrer_id: "user1",
+        referred_email: "friend@test.com",
+        referral_code: "testuser",
+        status: "pending",
+      },
+    ]);
+  });
+});

src/app/api/referrals/route.ts

@@ -80,7 +80,9 @@ export async function POST(request: NextRequest) {
     // Only valid emails should count toward throttle limits
     const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
     const normalizedEmails = emails.map((e: string) => e.trim().toLowerCase());
-    const validEmails = normalizedEmails.filter((e: string) => emailRegex.test(e));
+    const validEmails = Array.from(
+      new Set(normalizedEmails.filter((e: string) => emailRegex.test(e)))
+    );
 
     if (validEmails.length === 0) {
       return NextResponse.json(