From dd375859a46748062a9d9b0f73800fedfce6f148 Mon Sep 17 00:00:00 2001
From: Julien Gautier <julien.gautier@apf.asso.fr>
Date: Tue, 12 May 2026 22:28:28 +0200
Subject: [PATCH] =?UTF-8?q?fix(portal-shell):=20send=20withCredentials=20o?=
 =?UTF-8?q?n=20/me=20so=20the=20session=20cookie=20crosses=20SPA=E2=86=92B?=
 =?UTF-8?q?FF=20in=20dev?=
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manual smoke surfaced the bug: the callback wrote the session and
set the portal_session cookie correctly, but the spa's next /me call
came back 401 with no cookie header at all.

root cause: angular's HttpClient via withFetch() inherits fetch's
default `credentials: 'same-origin'`. localhost:4200 → localhost:3000
is cross-origin (different ports), so the session cookie is dropped
on the way out — the bff never sees it. samesite=lax was a red
herring: localhost:4200 and localhost:3000 share the registrable
domain, so the cookie is still same-site; what was missing was
opting the fetch into credentials.

fix is per-call: only /me needs cookies today. login/logout are
full-page navigations through window.location, which the browser
hydrates with cookies regardless. a global HttpInterceptor will land
when other authenticated bff endpoints exist — premature for one
consumer.

bff side was already wired: enableCors({ credentials: true }) in
main.ts. nothing to change there.

a spec pins withCredentials=true on the /me request so a future
refactor can't silently drop the flag and reintroduce the bug.
---
 libs/feature/auth/src/lib/auth.service.spec.ts | 12 ++++++++++++
 libs/feature/auth/src/lib/auth.service.ts      | 13 ++++++++++++-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/libs/feature/auth/src/lib/auth.service.spec.ts b/libs/feature/auth/src/lib/auth.service.spec.ts
index 7aac605..83ebee3 100644
--- a/libs/feature/auth/src/lib/auth.service.spec.ts
+++ b/libs/feature/auth/src/lib/auth.service.spec.ts
@@ -62,6 +62,18 @@ describe('AuthService', () => {
       expect(service.isLoading()).toBe(false);
     });
 
+    it('issues /me with withCredentials so the session cookie crosses the SPA→BFF origin gap', () => {
+      const { http } = setup();
+      const req = http.expectOne(ME_URL);
+      // Without this, `fetch`'s default `credentials: 'same-origin'`
+      // would suppress the session cookie on the cross-origin
+      // (localhost:4200 → localhost:3000) request and /me would
+      // always answer 401 in dev. Verified manually against the BFF
+      // log on 2026-05-12.
+      expect(req.request.withCredentials).toBe(true);
+      req.flush({ error: 'unauthenticated' }, { status: 401, statusText: 'Unauthorized' });
+    });
+
     it('transitions to anonymous on 401', async () => {
       const { service, http } = setup();
       http
diff --git a/libs/feature/auth/src/lib/auth.service.ts b/libs/feature/auth/src/lib/auth.service.ts
index cc8043a..212fe0b 100644
--- a/libs/feature/auth/src/lib/auth.service.ts
+++ b/libs/feature/auth/src/lib/auth.service.ts
@@ -58,7 +58,18 @@ export class AuthService {
    */
   async refresh(): Promise<void> {
     try {
-      const user = await firstValueFrom(this.http.get<CurrentUser>(this.meUrl));
+      // `withCredentials: true` is mandatory: the SPA at
+      // http://localhost:4200 calls the BFF at http://localhost:3000 —
+      // different origins, so `fetch`'s default `credentials:
+      // 'same-origin'` would drop the `__Host-portal_session` cookie
+      // and /me would always answer 401. Production (single origin
+      // behind the same edge) doesn't need it but it's harmless there.
+      // CORS on the BFF side already allows credentials
+      // (`apps/portal-bff/src/main.ts` → `enableCors({ credentials:
+      // true })`).
+      const user = await firstValueFrom(
+        this.http.get<CurrentUser>(this.meUrl, { withCredentials: true }),
+      );
       this._state.set({ kind: 'authenticated', user });
     } catch (err) {
       this._state.set(toErrorState(err));