fix NPE in ActivityTestCase#scrubClass

Change-Id: I1fd5c48682527fa0fee2b34eea95abc263138b5c

2 files changed, 69 insertions, 2 deletions

diff --git a/src/com/google/android/droiddriver/helpers/BaseDroidDriverTest.java b/src/com/google/android/droiddriver/helpers/BaseDroidDriverTest.java
index b343d0f..b262f49 100644
--- a/src/com/google/android/droiddriver/helpers/BaseDroidDriverTest.java
+++ b/src/com/google/android/droiddriver/helpers/BaseDroidDriverTest.java
@@ -19,7 +19,6 @@ package com.google.android.droiddriver.helpers;
 import android.app.Activity;
 import android.content.Context;
 import android.os.Debug;
-import android.test.ActivityInstrumentationTestCase2;
 import android.util.Log;
 
 import com.google.android.droiddriver.DroidDriver;
@@ -36,7 +35,7 @@ import java.lang.Thread.UncaughtExceptionHandler;
  * provides handy utility methods.
  */
 public abstract class BaseDroidDriverTest<T extends Activity> extends
-    ActivityInstrumentationTestCase2<T> {
+    D2ActivityInstrumentationTestCase2<T> {
   private static boolean classSetUpDone = false;
   // In case of device-wide fatal errors, e.g. OOME, the remaining tests will
   // fail and the messages will not help, so skip them.
diff --git a/src/com/google/android/droiddriver/helpers/D2ActivityInstrumentationTestCase2.java b/src/com/google/android/droiddriver/helpers/D2ActivityInstrumentationTestCase2.java
new file mode 100644
index 0000000..ec5ea9f
--- /dev/null
+++ b/src/com/google/android/droiddriver/helpers/D2ActivityInstrumentationTestCase2.java
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2013 DroidDriver committers
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.droiddriver.helpers;
+
+import android.app.Activity;
+import android.test.ActivityInstrumentationTestCase2;
+import android.test.ActivityTestCase;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+
+/**
+ * Fixes bugs in {@link ActivityInstrumentationTestCase2}.
+ */
+public abstract class D2ActivityInstrumentationTestCase2<T extends Activity> extends
+    ActivityInstrumentationTestCase2<T> {
+  protected D2ActivityInstrumentationTestCase2(Class<T> activityClass) {
+    super(activityClass);
+  }
+
+  /**
+   * Fixes a bug in {@link ActivityTestCase#scrubClass} that causes
+   * NullPointerException if your leaf-level test class declares static fields.
+   * This is <a href="https://code.google.com/p/android/issues/detail?id=4244">a
+   * known bug</a> that has been fixed in ICS Android release. But it still
+   * exists on devices older than ICS. If your test class extends this class, it
+   * can work on older devices.
+   * <p>
+   * In addition to the official fix in ICS and beyond, which skips
+   * {@code final} fields, the fix below also skips {@code static} fields, which
+   * should be the expectation of Java programmers.
+   * </p>
+   */
+  @Override
+  protected void scrubClass(final Class<?> testCaseClass) throws IllegalAccessException {
+    final Field[] fields = getClass().getDeclaredFields();
+    for (Field field : fields) {
+      final Class<?> fieldClass = field.getDeclaringClass();
+      if (testCaseClass.isAssignableFrom(fieldClass) && !field.getType().isPrimitive()
+          && !Modifier.isFinal(field.getModifiers()) && !Modifier.isStatic(field.getModifiers())) {
+        try {
+          field.setAccessible(true);
+          field.set(this, null);
+        } catch (Exception e) {
+          android.util.Log.d("TestCase", "Error: Could not nullify field!");
+        }
+
+        if (field.get(this) != null) {
+          android.util.Log.d("TestCase", "Error: Could not nullify field!");
+        }
+      }
+    }
+  }
+}