RCORE-2200: Fix switch_user and get_profile during log_in_with_credentials

CHANGELOG.md

@@ -6,7 +6,7 @@
 
 ### Fixed
 * <How do the end-user experience this issue? what was the impact?> ([#????](https://github.com/realm/realm-core/issues/????), since v?.?.?)
-* None.
+* App subscription callback was getting fired before the user profile was retrieved on login, leading to an empty user profile when using the callback. ([#7889](https://github.com/realm/realm-core/issues/7889), since v14.7.0)
 
 ### Breaking changes
 * None.

src/realm/object-store/sync/app.cpp

@@ -835,8 +835,14 @@ void App::log_in_with_credentials(const AppCredentials& credentials, const std::
                 return completion(nullptr,
                                   AppError(ErrorCodes::BadToken, "Could not log in user: received malformed JWT"));
             }
-            switch_user(user);
-            get_profile(user, std::move(completion));
+
+            get_profile(user, [this, completion = std::move(completion)](const std::shared_ptr<User>& user,
+                                                                         Optional<AppError> error) {
+                if (!error) {
+                    switch_user(user);
+                }
+                completion(user, error);
+            });
         },
         false);
 }

test/object-store/sync/app.cpp

@@ -4172,6 +4172,17 @@ TEST_CASE("app: jwt login and metadata tests", "[sync][app][user][metadata][func
 
     SECTION("jwt happy path") {
         bool processed = false;
+        bool logged_in_once = false;
+
+        auto token = app->subscribe([&logged_in_once, &app](auto&) {
+            REQUIRE(!logged_in_once);
+            auto user = app->current_user();
+            auto metadata = user->user_profile();
+
+            // Ensure that the JWT metadata fields are available when the callback is fired on login.
+            CHECK(metadata["name"] == "Foo Bar");
+            logged_in_once = true;
+        });
 
         std::shared_ptr<User> user = log_in(app, AppCredentials::custom(jwt));
 
@@ -4192,6 +4203,10 @@ TEST_CASE("app: jwt login and metadata tests", "[sync][app][user][metadata][func
         auto custom_data = *user->custom_data();
         CHECK(custom_data["name"] == "Not Foo Bar");
         CHECK(metadata["name"] == "Foo Bar");
+
+        REQUIRE(logged_in_once);
+
+        app->unsubscribe(token);
     }
 }