fix(api): identify session clients correctly and attribute handoff sessions (#1727)

fluxer_api/src/api/auth/tests/DesktopHandoffFlow.test.ts

@@ -1,10 +1,12 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later
 
 import {APIErrorCodes} from '@fluxer/constants/src/ApiErrorCodes';
+import {maskIpForDisplay} from '@fluxer/ip_utils/src/IpAddress';
 import {afterAll, beforeAll, beforeEach, describe, expect, it} from 'vitest';
 import type {ApiTestHarness} from '../../test/ApiTestHarness';
 import {HTTP_STATUS} from '../../test/TestConstants';
-import {createBuilderWithoutAuth} from '../../test/TestRequestBuilder';
+import {createBuilder, createBuilderWithoutAuth} from '../../test/TestRequestBuilder';
+
 import {createAuthHarness, createTestAccount, fetchMe, loginAccount} from './AuthTestUtils';
 
 interface HandoffInitiateResponse {
@@ -17,6 +19,7 @@ interface HandoffInfoResponse {
 	client_info?: {
 		platform?: string | null;
 		os?: string | null;
+		device?: 'mobile' | 'desktop';
 		location?: {
 			city?: string | null;
 			region?: string | null;
@@ -25,6 +28,16 @@ interface HandoffInfoResponse {
 	} | null;
 }
 
+interface AuthSessionsResponseItem {
+	masked_ip?: string | null;
+	client_info?: {
+		platform?: string | null;
+		os?: string | null;
+		browser?: string | null;
+		device?: 'mobile' | 'desktop';
+	} | null;
+}
+
 interface HandoffStatusResponse {
 	status: 'pending' | 'completed' | 'expired';
 	token?: string;
@@ -53,6 +66,46 @@ describe('Auth desktop handoff flow', () => {
 	afterAll(async () => {
 		await harness?.shutdown();
 	});
+	it('attributes the handed-off session to the initiating desktop, not the approving browser', async () => {
+		const DESKTOP_IP = '203.0.113.77';
+		const desktopUserAgent =
+			'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) FluxerStable/1.4.0 Chrome/128.0.0.0 Electron/32.0.0 Safari/537.36';
+		const browserUserAgent =
+			'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36';
+		const account = await createTestAccount(harness);
+		const login = await loginAccount(harness, account);
+		const initResp = await createBuilderWithoutAuth<HandoffInitiateResponse>(harness)
+			.post('/auth/handoff/initiate')
+			.header('User-Agent', desktopUserAgent)
+			.header('x-forwarded-for', DESKTOP_IP)
+			.body(null)
+			.execute();
+		const info = await createBuilderWithoutAuth<HandoffInfoResponse>(harness)
+			.get(`/auth/handoff/${initResp.code}/info`)
+			.header('User-Agent', browserUserAgent)
+			.execute();
+		expect(info.client_info?.platform).toBe('Fluxer macOS');
+		expect(info.client_info?.device).toBe('desktop');
+		await createBuilderWithoutAuth(harness)
+			.post('/auth/handoff/complete')
+			.header('User-Agent', browserUserAgent)
+			.body({code: initResp.code, token: login.token, user_id: login.userId})
+			.expect(204)
+			.execute();
+		const completed = await createBuilderWithoutAuth<HandoffStatusResponse>(harness)
+			.get(`/auth/handoff/${initResp.code}/status`)
+			.execute();
+		const sessions = await createBuilder<Array<AuthSessionsResponseItem>>(harness, completed.token!)
+			.get('/auth/sessions')
+			.execute();
+		const handedOff = sessions.filter((session) => session.client_info?.platform === 'Fluxer macOS');
+		expect(handedOff).toHaveLength(1);
+		expect(handedOff[0]?.client_info?.os).toBe('macOS');
+		expect(handedOff[0]?.client_info?.browser).toBeNull();
+		expect(handedOff[0]?.client_info?.device).toBe('desktop');
+		expect(sessions.some((session) => session.client_info?.browser === 'Chrome')).toBe(false);
+		expect(handedOff[0]?.masked_ip).toBe(maskIpForDisplay(DESKTOP_IP));
+	});
 	it('completes full handoff flow: initiate → info → complete → status', async () => {
 		const account = await createTestAccount(harness);
 		const login = await loginAccount(harness, account);