Adding support for Activity and Fragment coming from the support libr…

…aries: (#275)

Adding support for:
* Fragment and Activity classes that are coming from the support library and Android X
* onCreateView and onAttach for the Fragment

* Adding a fragment to test the changes for onCreate, onCreateView and onAttach

* Adding unit tests

nullaway/src/main/java/com/uber/nullaway/ErrorProneCLIFlagsConfig.java

@@ -73,8 +73,22 @@ final class ErrorProneCLIFlagsConfig extends AbstractConfig {
           "android.app.Service.onCreate",
           "android.app.Activity.onCreate",
           "android.app.Fragment.onCreate",
+          "android.app.Fragment.onAttach",
+          "android.app.Fragment.onCreateView",
           "android.app.Application.onCreate",
-          "javax.annotation.processing.Processor.init");
+          "javax.annotation.processing.Processor.init",
+          // Support Library v4 - can be removed once AndroidX becomes more popular
+          "android.support.v4.app.ActivityCompat.onCreate",
+          "android.support.v4.app.Fragment.onCreate",
+          "android.support.v4.app.Fragment.onAttach",
+          "android.support.v4.app.Fragment.onCreateView",
+          // Support Library v4 - can be removed once AndroidX becomes more popular
+          "androidx.core.app.ActivityCompat.onCreate",
+          "androidx.fragment.app.Fragment.onCreate",
+          "androidx.fragment.app.Fragment.onAttach",
+          "androidx.fragment.app.Fragment.onCreateView",
+          // Multidex app
+          "android.support.multidex.Application.onCreate");
 
   static final ImmutableSet<String> DEFAULT_INITIALIZER_ANNOT =
       ImmutableSet.of(

nullaway/src/test/java/com/uber/nullaway/NullAwayAndroidTest.java

@@ -0,0 +1,186 @@
+package com.uber.nullaway;
+
+import com.google.errorprone.CompilationTestHelper;
+import java.util.Arrays;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Unit tests for {@link com.uber.nullaway.NullAway}. */
+@RunWith(JUnit4.class)
+@SuppressWarnings("CheckTestExtendsBaseClass")
+public class NullAwayAndroidTest {
+  @Rule public final TemporaryFolder temporaryFolder = new TemporaryFolder();
+
+  private CompilationTestHelper compilationHelper;
+
+  @Before
+  public void setup() {
+    compilationHelper = CompilationTestHelper.newInstance(NullAway.class, getClass());
+    compilationHelper.setArgs(
+        Arrays.asList(
+            "-d",
+            temporaryFolder.getRoot().getAbsolutePath(),
+            "-XepOpt:NullAway:AnnotatedPackages=com.uber,com.ubercab,io.reactivex"));
+  }
+
+  // Core Fragment tests
+
+  @Test
+  public void coreFragmentSuccess() {
+    initialiseAndroidCoreClasses();
+    compilationHelper
+        .addSourceFile("androidstubs/core/Fragment.java")
+        .addSourceFile("android-success/CoreFragment.java")
+        .doTest();
+  }
+
+  @Test
+  public void coreFragmentMissingOnAttachError() {
+    initialiseAndroidCoreClasses();
+    compilationHelper
+        .addSourceFile("androidstubs/core/Fragment.java")
+        .addSourceFile("android-error/CoreFragmentWithoutOnAttach.java")
+        .doTest();
+  }
+
+  @Test
+  public void coreFragmentMissingOnCreateError() {
+    initialiseAndroidCoreClasses();
+    compilationHelper
+        .addSourceFile("androidstubs/core/Fragment.java")
+        .addSourceFile("android-error/CoreFragmentWithoutOnCreate.java")
+        .doTest();
+  }
+
+  @Test
+  public void coreFragmentMissingOnCreateViewError() {
+    initialiseAndroidCoreClasses();
+    compilationHelper
+        .addSourceFile("androidstubs/core/Fragment.java")
+        .addSourceFile("android-error/CoreFragmentWithoutOnCreateView.java")
+        .doTest();
+  }
+
+  // AndroidX Library Fragment
+  @Test
+  public void androidxFragmentSuccess() {
+    initialiseAndroidCoreClasses();
+    compilationHelper
+        .addSourceFile("androidstubs/androidx/Fragment.java")
+        .addSourceFile("android-success/AndroidxFragment.java")
+        .doTest();
+  }
+
+  @Test
+  public void androidxFragmentMissingOnAttachError() {
+    initialiseAndroidCoreClasses();
+    compilationHelper
+        .addSourceFile("androidstubs/androidx/Fragment.java")
+        .addSourceFile("android-error/AndroidxFragmentWithoutOnAttach.java")
+        .doTest();
+  }
+
+  @Test
+  public void androidxFragmentMissingOnCreateError() {
+    initialiseAndroidCoreClasses();
+    compilationHelper
+        .addSourceFile("androidstubs/androidx/Fragment.java")
+        .addSourceFile("android-error/AndroidxFragmentWithoutOnCreate.java")
+        .doTest();
+  }
+
+  @Test
+  public void androidxFragmentMissingOnCreateViewError() {
+    initialiseAndroidCoreClasses();
+    compilationHelper
+        .addSourceFile("androidstubs/androidx/Fragment.java")
+        .addSourceFile("android-error/AndroidxFragmentWithoutOnCreateView.java")
+        .doTest();
+  }
+
+  // Android support library Fragment
+
+  @Test
+  public void supportLibFragmentSuccess() {
+    initialiseAndroidCoreClasses();
+    compilationHelper
+        .addSourceFile("androidstubs/supportlib/Fragment.java")
+        .addSourceFile("android-success/SupportLibraryFragment.java")
+        .doTest();
+  }
+
+  @Test
+  public void supportLibFragmentMissingOnAttachError() {
+    initialiseAndroidCoreClasses();
+    compilationHelper
+        .addSourceFile("androidstubs/supportlib/Fragment.java")
+        .addSourceFile("android-error/SupportLibraryFragmentWithoutOnAttach.java")
+        .doTest();
+  }
+
+  @Test
+  public void supportLibFragmentMissingOnCreateError() {
+    initialiseAndroidCoreClasses();
+    compilationHelper
+        .addSourceFile("androidstubs/supportlib/Fragment.java")
+        .addSourceFile("android-error/SupportLibraryFragmentWithoutOnCreate.java")
+        .doTest();
+  }
+
+  @Test
+  public void supportLibFragmentMissingOnCreateViewError() {
+    initialiseAndroidCoreClasses();
+    compilationHelper
+        .addSourceFile("androidstubs/supportlib/Fragment.java")
+        .addSourceFile("android-error/SupportLibraryFragmentWithoutOnCreateView.java")
+        .doTest();
+  }
+
+  // Core Activity
+
+  @Test
+  public void coreActivitySuccess() {
+    initialiseAndroidCoreClasses();
+    compilationHelper
+        .addSourceFile("androidstubs/core/Activity.java")
+        .addSourceFile("android-success/CoreActivity.java")
+        .doTest();
+  }
+
+  // Support Library Activity
+
+  @Test
+  public void supportLibActivitySuccess() {
+    initialiseAndroidCoreClasses();
+    compilationHelper
+        .addSourceFile("androidstubs/supportlib/ActivityCompat.java")
+        .addSourceFile("android-success/SupportLibActivityCompat.java")
+        .doTest();
+  }
+
+  // AndroidX Library Activity
+
+  @Test
+  public void androidxActivitySuccess() {
+    initialiseAndroidCoreClasses();
+    compilationHelper
+        .addSourceFile("androidstubs/androidx/ActivityCompat.java")
+        .addSourceFile("android-success/AndroidxActivityCompat.java")
+        .doTest();
+  }
+
+  /** Initialises the default android classes that are commonly used. */
+  private void initialiseAndroidCoreClasses() {
+    compilationHelper
+        .addSourceFile("androidstubs/core/Context.java")
+        .addSourceFile("androidstubs/core/Bundle.java")
+        .addSourceFile("androidstubs/core/LayoutInflater.java")
+        .addSourceFile("androidstubs/core/PersistableBundle.java")
+        .addSourceFile("androidstubs/core/View.java")
+        .addSourceFile("androidstubs/core/ViewGroup.java");
+  }
+}

nullaway/src/test/resources/com/uber/nullaway/testdata/android-error/AndroidxFragmentWithoutOnAttach.java

@@ -0,0 +1,28 @@
+package com.uber.myapplication;
+
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import androidx.fragment.app.Fragment;
+
+public class AndroidxFragmentWithoutOnAttach extends Fragment {
+
+  private Object mOnCreateInitialisedField;
+  private Object mOnCreateViewInitialisedField;
+  // BUG: Diagnostic contains: @NonNull field mOnAttachInitialisedField not initialized
+  private Object mOnAttachInitialisedField;
+
+  @Override
+  public void onCreate(Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+    mOnCreateInitialisedField = new Object();
+  }
+
+  @Override
+  public View onCreateView(
+      LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+    mOnCreateViewInitialisedField = new Object();
+    return super.onCreateView(inflater, container, savedInstanceState);
+  }
+}

nullaway/src/test/resources/com/uber/nullaway/testdata/android-error/AndroidxFragmentWithoutOnCreate.java

@@ -0,0 +1,28 @@
+package com.uber.myapplication;
+
+import android.content.Context;
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import androidx.fragment.app.Fragment;
+
+public class AndroidxFragmentWithoutOnCreate extends Fragment {
+  // BUG: Diagnostic contains: @NonNull field mOnCreateInitialisedField not initialized
+  private Object mOnCreateInitialisedField;
+  private Object mOnCreateViewInitialisedField;
+  private Object mOnAttachInitialisedField;
+
+  @Override
+  public View onCreateView(
+      LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+    mOnCreateViewInitialisedField = new Object();
+    return super.onCreateView(inflater, container, savedInstanceState);
+  }
+
+  @Override
+  public void onAttach(Context context) {
+    super.onAttach(context);
+    mOnAttachInitialisedField = new Object();
+  }
+}

nullaway/src/test/resources/com/uber/nullaway/testdata/android-error/AndroidxFragmentWithoutOnCreateView.java

@@ -0,0 +1,25 @@
+package com.uber.myapplication;
+
+import android.content.Context;
+import android.os.Bundle;
+import androidx.fragment.app.Fragment;
+
+public class AndroidxFragmentWithoutOnCreateView extends Fragment {
+
+  private Object mOnCreateInitialisedField;
+  // BUG: Diagnostic contains: @NonNull field mOnCreateViewInitialisedField not initialized
+  private Object mOnCreateViewInitialisedField;
+  private Object mOnAttachInitialisedField;
+
+  @Override
+  public void onCreate(Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+    mOnCreateInitialisedField = new Object();
+  }
+
+  @Override
+  public void onAttach(Context context) {
+    super.onAttach(context);
+    mOnAttachInitialisedField = new Object();
+  }
+}

nullaway/src/test/resources/com/uber/nullaway/testdata/android-error/CoreFragmentWithoutOnAttach.java

@@ -0,0 +1,28 @@
+package com.uber.myapplication;
+
+import android.app.Fragment;
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+public class CoreFragmentWithoutOnAttach extends Fragment {
+
+  private Object mOnCreateInitialisedField;
+  private Object mOnCreateViewInitialisedField;
+  // BUG: Diagnostic contains: @NonNull field mOnAttachInitialisedField not initialized
+  private Object mOnAttachInitialisedField;
+
+  @Override
+  public void onCreate(Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+    mOnCreateInitialisedField = new Object();
+  }
+
+  @Override
+  public View onCreateView(
+      LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+    mOnCreateViewInitialisedField = new Object();
+    return super.onCreateView(inflater, container, savedInstanceState);
+  }
+}

nullaway/src/test/resources/com/uber/nullaway/testdata/android-error/CoreFragmentWithoutOnCreate.java

@@ -0,0 +1,28 @@
+package com.uber.myapplication;
+
+import android.app.Fragment;
+import android.content.Context;
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+public class CoreFragmentWithoutOnCreate extends Fragment {
+  // BUG: Diagnostic contains: @NonNull field mOnCreateInitialisedField not initialized
+  private Object mOnCreateInitialisedField;
+  private Object mOnCreateViewInitialisedField;
+  private Object mOnAttachInitialisedField;
+
+  @Override
+  public View onCreateView(
+      LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+    mOnCreateViewInitialisedField = new Object();
+    return super.onCreateView(inflater, container, savedInstanceState);
+  }
+
+  @Override
+  public void onAttach(Context context) {
+    super.onAttach(context);
+    mOnAttachInitialisedField = new Object();
+  }
+}

nullaway/src/test/resources/com/uber/nullaway/testdata/android-error/CoreFragmentWithoutOnCreateView.java

@@ -0,0 +1,25 @@
+package com.uber.myapplication;
+
+import android.app.Fragment;
+import android.content.Context;
+import android.os.Bundle;
+
+public class CoreFragmentWithoutOnCreateView extends Fragment {
+
+  private Object mOnCreateInitialisedField;
+  // BUG: Diagnostic contains: @NonNull field mOnCreateViewInitialisedField not initialized
+  private Object mOnCreateViewInitialisedField;
+  private Object mOnAttachInitialisedField;
+
+  @Override
+  public void onCreate(Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+    mOnCreateInitialisedField = new Object();
+  }
+
+  @Override
+  public void onAttach(Context context) {
+    super.onAttach(context);
+    mOnAttachInitialisedField = new Object();
+  }
+}