add test

Signed-off-by: Stephen Glass <stephen@stephen.glass>

plugins/auth-node/src/oauth/createAuthErrorCookie.ts

@@ -14,7 +14,6 @@
  * limitations under the License.
  */
 import { Response } from 'express';
-import { CookieConfigurer } from '../types';
 import { serializeError } from '@backstage/errors';
 
 const ONE_MINUTE_MS = 60 * 1000;
@@ -29,7 +28,7 @@ function configureAuthErrorCookie(apiUrl: string, appOrigin: string) {
   // different domain than the app, we set the SameSite attribute
   // to 'none' to allow third-party access to the cookie, but
   // only if it's in a secure context (https).
-  let sameSite: ReturnType<CookieConfigurer>['sameSite'] = 'lax';
+  let sameSite: 'lax' | 'none' = 'lax';
   if (new URL(appOrigin).hostname !== domain && secure) {
     sameSite = 'none';
   }

plugins/auth-node/src/oauth/createOAuthRouteHandlers.test.ts

@@ -742,5 +742,29 @@ describe('createOAuthRouteHandlers', () => {
         },
       });
     });
+
+    it('should set cookie on caught error redirect', async () => {
+      const app = wrapInApp(createOAuthRouteHandlers(baseConfig));
+      const res = await request(app)
+        .get('/my-provider/handler/frame')
+        .query({
+          state: encodeOAuthState({
+            env: 'development',
+            nonce: '123',
+            flow: 'redirect',
+            redirectUrl: 'http://localhost:3000',
+          }),
+        });
+
+      // redirects on error with auth error cookie
+      expect(res.status).toBe(302);
+      const setCookieHeader = res.header['set-cookie'];
+      expect(setCookieHeader).toBeDefined();
+
+      const authErrorCookie = setCookieHeader.find((cookie: string) =>
+        cookie.startsWith('auth-error='),
+      );
+      expect(authErrorCookie).toBeDefined();
+    });
   });
 });