feat/ab test landing google auth (#62538)

api/src/plugins/auth0.test.ts

@@ -42,6 +42,37 @@ describe('auth0 plugin', () => {
     await fastify.register(prismaPlugin);
   });
 
+  describe('GET /signin/google', () => {
+    test('should redirect directly to Google via Auth0 with connection param', async () => {
+      const res = await fastify.inject({
+        method: 'GET',
+        url: '/signin/google'
+      });
+      const redirectUrl = new URL(res.headers.location!);
+      expect(redirectUrl.host).toMatch(AUTH0_DOMAIN);
+      expect(redirectUrl.pathname).toBe('/authorize');
+      expect(redirectUrl.searchParams.get('connection')).toBe('google-oauth2');
+      expect(res.statusCode).toBe(302);
+    });
+
+    test('sets a login-returnto cookie', async () => {
+      const returnTo = 'http://localhost:3000/learn';
+      const res = await fastify.inject({
+        method: 'GET',
+        url: '/signin/google',
+        headers: { referer: returnTo }
+      });
+      const cookie = res.cookies.find(c => c.name === 'login-returnto');
+      expect(unsign(cookie!.value).value).toBe(returnTo);
+      expect(cookie).toMatchObject({
+        domain: COOKIE_DOMAIN,
+        httpOnly: true,
+        secure: true,
+        sameSite: 'Lax'
+      });
+    });
+  });
+
   afterAll(async () => {
     await fastify.prisma.$runCommandRaw({ dropDatabase: 1 });
     await fastify.close();

api/src/plugins/auth0.ts

@@ -82,6 +82,25 @@ export const auth0Client: FastifyPluginCallbackTypebox = fp(
         );
         void reply.redirect(redirectUrl);
       });
+
+      fastify.get('/signin/google', async function (request, reply) {
+        const returnTo = request.headers.referer ?? `${HOME_LOCATION}/learn`;
+        void reply.setCookie('login-returnto', returnTo, {
+          domain: COOKIE_DOMAIN,
+          httpOnly: true,
+          secure: true,
+          signed: true,
+          sameSite: 'lax'
+        });
+
+        const authorizationEndpoint =
+          await this.auth0OAuth.generateAuthorizationUri(request, reply);
+
+        const url = new URL(authorizationEndpoint);
+        url.searchParams.set('connection', 'google-oauth2');
+
+        void reply.redirect(url.toString());
+      });
       done();
     });