[quick_actions_android] Return null from getLaunchAction when no activity is attached

packages/quick_actions/quick_actions_android/android/src/main/java/io/flutter/plugins/quickactions/QuickActions.java

@@ -11,6 +11,7 @@
 import android.content.Intent;
 import android.content.res.Resources;
 import android.os.Build;
+import android.util.Log;
 import androidx.annotation.ChecksSdkIntAtLeast;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
@@ -28,6 +29,7 @@
 import org.jetbrains.annotations.NotNull;
 
 final class QuickActions implements AndroidQuickActionsApi {
+  private static final String TAG = "QuickActionsAndroid";
   static final String EXTRA_ACTION = "some unique action key";
 
   private final Context context;
@@ -102,10 +104,12 @@ public void clearShortcutItems() {
       return null;
     }
     if (activity == null) {
-      throw new FlutterError(
-          "quick_action_getlaunchaction_no_activity",
-          "There is no activity available when launching action",
-          null);
+      // The engine can run without an attached activity, for instance when it is cached and warmed
+      // up by a background service. Nothing launched the app in that case, so there is no launch
+      // action to report. Any action that arrives later is reported through the plugin's
+      // onNewIntent listener once an activity attaches.
+      Log.d(TAG, "There is no activity available when getting the launch action.");
+      return null;
     }
     final Intent intent = activity.getIntent();
     final String launchAction = intent.getStringExtra(EXTRA_ACTION);

packages/quick_actions/quick_actions_android/android/src/test/java/io/flutter/plugins/quickactions/QuickActionsTest.java

@@ -6,8 +6,11 @@
 
 import static io.flutter.plugins.quickactions.QuickActions.EXTRA_ACTION;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.when;
 
 import android.app.Activity;
@@ -50,6 +53,21 @@ public void setMessageHandler(@NonNull String channel, @Nullable BinaryMessageHa
   static final int UNSUPPORTED_BUILD = 24;
   static final String SHORTCUT_TYPE = "action_one";
 
+  @Test
+  public void getLaunchAction_noActivity_returnsNull() {
+    // Arrange
+    // Build.VERSION.SDK_INT is 0 in unit tests, so the version check is stubbed to make sure the
+    // null activity, and not the unsupported version, is what is being exercised here.
+    final QuickActions quickActions = spy(new QuickActions(mock(Context.class)));
+    doReturn(true).when(quickActions).isVersionAllowed();
+
+    // Act
+    final String launchAction = quickActions.getLaunchAction();
+
+    // Assert
+    assertNull(launchAction);
+  }
+
   @Test
   public void canAttachToEngine() {
     final TestBinaryMessenger testBinaryMessenger = new TestBinaryMessenger();