Adds the dagger.hilt.android.useFragmentGetContextFix flag to guard t…

…he corrected Fragment.getContext() behavior. RELNOTES=Adds the dagger.hilt.android.useFragmentGetContextFix flag to guard the corrected Fragment.getContext() behavior PiperOrigin-RevId: 375801929
google · May 25, 2021 · 5ce0cea · 5ce0cea
1 parent 9bfc67e
commit 5ce0cea
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Showing 4 changed files with 41 additions and 5 deletions.
diff --git a/java/dagger/hilt/android/processor/internal/androidentrypoint/BUILD b/java/dagger/hilt/android/processor/internal/androidentrypoint/BUILD
@@ -63,6 +63,7 @@ java_library(
         "//java/dagger/hilt/android/processor/internal:android_classnames",
         "//java/dagger/hilt/android/processor/internal:utils",
         "//java/dagger/hilt/processor/internal:classnames",
+        "//java/dagger/hilt/processor/internal:compiler_options",
         "//java/dagger/hilt/processor/internal:component_names",
         "//java/dagger/hilt/processor/internal:processor_errors",
         "//java/dagger/hilt/processor/internal:processors",

diff --git a/java/dagger/hilt/android/processor/internal/androidentrypoint/FragmentGenerator.java b/java/dagger/hilt/android/processor/internal/androidentrypoint/FragmentGenerator.java
@@ -16,6 +16,8 @@
 
 package dagger.hilt.android.processor.internal.androidentrypoint;
 
+import static dagger.hilt.processor.internal.HiltCompilerOptions.useFragmentGetContextFix;
+
 import com.squareup.javapoet.ClassName;
 import com.squareup.javapoet.FieldSpec;
 import com.squareup.javapoet.JavaFile;
@@ -176,12 +178,21 @@ private MethodSpec initializeComponentContextMethod() {
   //   initializeComponentContext();
   //   return componentContext;
   // }
-  private static MethodSpec getContextMethod() {
-    return MethodSpec.methodBuilder("getContext")
+  private MethodSpec getContextMethod() {
+    MethodSpec.Builder builder = MethodSpec.methodBuilder("getContext")
         .returns(AndroidClassNames.CONTEXT)
         .addAnnotation(Override.class)
-        .addModifiers(Modifier.PUBLIC)
-        .beginControlFlow("if (super.getContext() == null)")
+        .addModifiers(Modifier.PUBLIC);
+
+    if (useFragmentGetContextFix(env)) {
+      builder.beginControlFlow("if (super.getContext() == null)");
+    } else {
+      builder.beginControlFlow(
+          "if (super.getContext() == null && $N == null)",
+          COMPONENT_CONTEXT_FIELD);
+    }
+
+    return builder
         .addStatement("return null")
         .endControlFlow()
         .addStatement("initializeComponentContext()")

diff --git a/java/dagger/hilt/processor/internal/HiltCompilerOptions.java b/java/dagger/hilt/processor/internal/HiltCompilerOptions.java
@@ -84,6 +84,16 @@ public static boolean useAggregatingRootProcessor(ProcessingEnvironment env) {
     return BooleanOption.USE_AGGREGATING_ROOT_PROCESSOR.get(env);
   }
 
+  /**
+   * Returns {@code true} if fragment code should use the fixed getContext() behavior where it
+   * correctly returns null after a fragment is removed. This fixed behavior matches the behavior
+   * of a regular fragment and can help catch issues where a removed or leaked fragment is
+   * incorrectly used.
+   */
+  public static boolean useFragmentGetContextFix(ProcessingEnvironment env) {
+    return BooleanOption.USE_FRAGMENT_GET_CONTEXT_FIX.get(env);
+  }
+
   /** Processor options which can have true or false values. */
   private enum BooleanOption {
     /** Do not use! This is for internal use only. */
@@ -97,7 +107,9 @@ private enum BooleanOption {
 
     DISABLE_MODULES_HAVE_INSTALL_IN_CHECK("disableModulesHaveInstallInCheck", false),
 
-    SHARE_TEST_COMPONENTS("shareTestComponents", false);
+    SHARE_TEST_COMPONENTS("shareTestComponents", false),
+
+    USE_FRAGMENT_GET_CONTEXT_FIX("android.useFragmentGetContextFix", false);
 
     private final String name;
     private final boolean defaultValue;

diff --git a/javatests/dagger/hilt/android/FragmentContextOnAttachTest.java b/javatests/dagger/hilt/android/FragmentContextOnAttachTest.java
@@ -74,4 +74,16 @@ public void testGetContextAvailableBeforeSuperOnAttach() throws Exception {
     assertThat(fragment.onAttachContextContext).isNotNull();
     assertThat(fragment.onAttachActivityContext).isNotNull();
   }
+
+  // Tests the default behavior of the useFragmentGetContextFix flag. Current default is false
+  // so this tests the broken behavior.
+  @Test
+  public void testGetContextDoesNotReturnNullAfterRemoval() throws Exception {
+    FragmentActivity activity = Robolectric.setupActivity(TestActivity.class);
+    TestFragment fragment = new TestFragment();
+    activity.getSupportFragmentManager().beginTransaction().add(fragment, "").commitNow();
+    assertThat(fragment.getContext()).isNotNull();
+    activity.getSupportFragmentManager().beginTransaction().remove(fragment).commitNow();
+    assertThat(fragment.getContext()).isNotNull();
+  }
 }