Fix crash with null pointer when accessing session (close #581)

PR #582
snowplow · Feb 15, 2023 · 3585118 · 3585118
1 parent bbc9919
commit 3585118
Show file tree

Hide file tree

Showing 6 changed files with 46 additions and 3 deletions.
diff --git a/...c/androidTest/java/com/snowplowanalytics/snowplow/internal/tracker/ConfigurationTest.java b/...c/androidTest/java/com/snowplowanalytics/snowplow/internal/tracker/ConfigurationTest.java
@@ -112,6 +112,15 @@ public void sessionInitialization() {
         assertEquals(expectedBackground, background);
     }
 
+    @Test
+    public void sessionIdEmptyBeforeSessionInitialized() {
+        Context context = InstrumentationRegistry.getInstrumentation().getTargetContext();
+        NetworkConfiguration networkConfig = new NetworkConfiguration("fake-url", HttpMethod.POST);
+        TrackerController tracker = Snowplow.createTracker(context, "emptySessionIdTest", networkConfig);
+        String sessionId = tracker.getSession().getSessionId();
+        assertEquals("", sessionId);
+    }
+
     @Test
     public void sessionControllerUnavailableWhenContextTurnedOff() {
         Context context = InstrumentationRegistry.getInstrumentation().getTargetContext();

diff --git a/...ker/src/androidTest/java/com/snowplowanalytics/snowplow/internal/tracker/TrackerTest.java b/...ker/src/androidTest/java/com/snowplowanalytics/snowplow/internal/tracker/TrackerTest.java
@@ -26,6 +26,7 @@
 import com.snowplowanalytics.snowplow.emitter.EventStore;
 import com.snowplowanalytics.snowplow.event.SelfDescribing;
 import com.snowplowanalytics.snowplow.event.Structured;
+import com.snowplowanalytics.snowplow.network.HttpMethod;
 import com.snowplowanalytics.snowplow.payload.SelfDescribingJson;
 import com.snowplowanalytics.snowplow.tracker.DevicePlatform;
 import com.snowplowanalytics.snowplow.internal.emitter.Emitter;
@@ -35,6 +36,7 @@
 import com.snowplowanalytics.snowplow.event.ScreenView;
 import com.snowplowanalytics.snowplow.event.Timing;
 import com.snowplowanalytics.snowplow.tracker.LogLevel;
+import com.snowplowanalytics.snowplow.tracker.MockNetworkConnection;
 
 import org.json.JSONArray;
 import org.json.JSONException;
@@ -399,6 +401,26 @@ public void testTrackWithSession() throws Exception {
         mockWebServer.shutdown();
     }
 
+    // This test was used to replicate issue #581 and fix it
+    @Test
+    public void testTrackWithPausedSessionDoesntThrowException() {
+        Emitter emitter = new Emitter(
+                getContext(),
+                "",
+                new Emitter.EmitterBuilder()
+                        .networkConnection(new MockNetworkConnection(HttpMethod.POST, 200)));
+
+        tracker = new Tracker(new Tracker.TrackerBuilder(emitter, "pausedSession", "myAppId", getContext())
+                .sessionContext(true)
+        );
+
+        // Pause session tracking
+        tracker.pauseSessionChecking();
+
+        // Track an event to make sure it does not throw an exception
+        tracker.track(new ScreenView("screen1"));
+    }
+
     @Test
     public void testTrackScreenView() {
         String namespace = "myNamespace";

diff --git a/...ow-tracker/src/main/java/com/snowplowanalytics/snowplow/controller/SessionController.java b/...ow-tracker/src/main/java/com/snowplowanalytics/snowplow/controller/SessionController.java
@@ -15,6 +15,7 @@ public interface SessionController extends SessionConfigurationInterface {
     /**
      * The session identifier.
      * A unique identifier which is used to identify the session.
+     * Returns an empty string if accessed before the session is initialized.
      */
     @NonNull
     String getSessionId();

diff --git a/snowplow-tracker/src/main/java/com/snowplowanalytics/snowplow/internal/session/Session.java b/snowplow-tracker/src/main/java/com/snowplowanalytics/snowplow/internal/session/Session.java
@@ -181,7 +181,7 @@ private synchronized static String retrieveUserId(Context context, SessionState
      *
      * @return a SelfDescribingJson containing the session context
      */
-    @NonNull
+    @Nullable
     public synchronized SelfDescribingJson getSessionContext(@NonNull String eventId, long eventTimestamp, boolean userAnonymisation) {
         Logger.v(TAG, "Getting session context...");
         if (isSessionCheckerEnabled) {
@@ -197,6 +197,10 @@ public synchronized SelfDescribingJson getSessionContext(@NonNull String eventId
             }
             lastSessionCheck = System.currentTimeMillis();
         }
+
+        SessionState state = getState();
+        if (state == null) { return null; }
+
         eventIndex += 1;
 
         Map<String, Object> sessionValues = state.getSessionValues();

diff --git a/.../src/main/java/com/snowplowanalytics/snowplow/internal/session/SessionControllerImpl.java b/.../src/main/java/com/snowplowanalytics/snowplow/internal/session/SessionControllerImpl.java
@@ -69,7 +69,12 @@ public String getSessionId() {
             Logger.track(TAG, "Attempt to access SessionController fields when disabled");
             return "";
         }
-        return session.getState().getSessionId();
+        SessionState state = session.getState();
+        if (state == null) {
+            Logger.track(TAG, "Attempt to access session information before session was initialized, use the onSessionUpdate callback");
+            return "";
+        }
+        return state.getSessionId();
     }
 
     @NonNull

diff --git a/snowplow-tracker/src/main/java/com/snowplowanalytics/snowplow/internal/tracker/Tracker.java b/snowplow-tracker/src/main/java/com/snowplowanalytics/snowplow/internal/tracker/Tracker.java
@@ -755,7 +755,9 @@ private void workaroundForIncoherentSessionContext(@NonNull TrackerEvent event)
                 return;
             }
             SelfDescribingJson sessionContextJson = sessionManager.getSessionContext(eventId, eventTimestamp, userAnonymisation);
-            event.contexts.add(sessionContextJson);
+            if (sessionContextJson != null) {
+                event.contexts.add(sessionContextJson);
+            }
         }
     }