Add auth/id-token-expired to verifyIdToken expired error message (#189)

Author: simenbrekken

src/auth/token-generator.ts

@@ -226,7 +226,7 @@ export class FirebaseTokenGenerator {
           if (error) {
             if (error.name === 'TokenExpiredError') {
               errorMessage = 'Firebase ID token has expired. Get a fresh token from your client app and try ' +
-                'again.' + verifyIdTokenDocsMessage;
+                'again (auth/id-token-expired).' + verifyIdTokenDocsMessage;
             } else if (error.name === 'JsonWebTokenError') {
               errorMessage = 'Firebase ID token has invalid signature.' + verifyIdTokenDocsMessage;
             }

test/unit/auth/token-generator.spec.ts

@@ -563,7 +563,7 @@ describe('FirebaseTokenGenerator', () => {
 
         // Token should now be invalid
         return tokenGenerator.verifyIdToken(mockIdToken)
-          .should.eventually.be.rejectedWith('Firebase ID token has expired');
+          .should.eventually.be.rejectedWith('Firebase ID token has expired. Get a fresh token from your client app and try again (auth/id-token-expired)');
       });
     });