Add test for Folder undoing behavior

Fix: 341799410
Test: FolderTest#undoFolder
Flag: TEST_ONLY
Change-Id: I8bfb3fc9348290274b33f4b5b6531126c658037c
diff --git a/src/com/android/launcher3/folder/Folder.java b/src/com/android/launcher3/folder/Folder.java
index dcc55e6..d3c1a02 100644
--- a/src/com/android/launcher3/folder/Folder.java
+++ b/src/com/android/launcher3/folder/Folder.java
@@ -65,6 +65,7 @@
 
 import androidx.annotation.IntDef;
 import androidx.annotation.Nullable;
+import androidx.annotation.VisibleForTesting;
 import androidx.core.content.res.ResourcesCompat;
 
 import com.android.launcher3.AbstractFloatingView;
@@ -1693,6 +1694,11 @@
         return windowBottomPx - folderBottomPx;
     }
 
+    @VisibleForTesting
+    public boolean getDeleteFolderOnDropCompleted() {
+        return mDeleteFolderOnDropCompleted;
+    }
+
     /**
      * Save this listener for the special case of when we update the state and concurrently
      * add another listener to {@link #mOnFolderStateChangedListeners} to avoid a
diff --git a/tests/src/com/android/launcher3/folder/FolderTest.kt b/tests/src/com/android/launcher3/folder/FolderTest.kt
new file mode 100644
index 0000000..e1daa74
--- /dev/null
+++ b/tests/src/com/android/launcher3/folder/FolderTest.kt
@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * 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.android.launcher3.folder
+
+import android.content.Context
+import android.graphics.Point
+import android.view.View
+import androidx.test.core.app.ApplicationProvider
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.filters.SmallTest
+import com.android.launcher3.DropTarget.DragObject
+import com.android.launcher3.LauncherAppState
+import com.android.launcher3.celllayout.board.FolderPoint
+import com.android.launcher3.celllayout.board.TestWorkspaceBuilder
+import com.android.launcher3.util.ActivityContextWrapper
+import com.android.launcher3.util.ModelTestExtensions.clearModelDb
+import junit.framework.TestCase.assertEquals
+import org.junit.After
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mockito
+import org.mockito.Mockito.times
+import org.mockito.Mockito.verify
+
+/** Tests for [Folder] */
+@SmallTest
+@RunWith(AndroidJUnit4::class)
+class FolderTest {
+
+    private val context: Context =
+        ActivityContextWrapper(ApplicationProvider.getApplicationContext())
+    private val workspaceBuilder = TestWorkspaceBuilder(context)
+    private val folder: Folder = Mockito.spy(Folder(context, null))
+
+    @After
+    fun tearDown() {
+        LauncherAppState.getInstance(context).model.clearModelDb()
+    }
+
+    @Test
+    fun `Undo a folder with 1 icon when onDropCompleted is called`() {
+        val folderInfo =
+            workspaceBuilder.createFolderInCell(FolderPoint(Point(1, 0), TWO_ICON_FOLDER_TYPE), 0)
+        folder.mInfo = folderInfo
+        folder.mInfo.getContents().removeAt(0)
+        folder.mContent = Mockito.mock(FolderPagedView::class.java)
+        val dragLayout = Mockito.mock(View::class.java)
+        val dragObject = Mockito.mock(DragObject::class.java)
+        assertEquals(folder.deleteFolderOnDropCompleted, false)
+        folder.onDropCompleted(dragLayout, dragObject, true)
+        verify(folder, times(1)).replaceFolderWithFinalItem()
+        assertEquals(folder.deleteFolderOnDropCompleted, false)
+    }
+
+    @Test
+    fun `Do not undo a folder with 2 icons when onDropCompleted is called`() {
+        val folderInfo =
+            workspaceBuilder.createFolderInCell(FolderPoint(Point(1, 0), TWO_ICON_FOLDER_TYPE), 0)
+        folder.mInfo = folderInfo
+        folder.mContent = Mockito.mock(FolderPagedView::class.java)
+        val dragLayout = Mockito.mock(View::class.java)
+        val dragObject = Mockito.mock(DragObject::class.java)
+        assertEquals(folder.deleteFolderOnDropCompleted, false)
+        folder.onDropCompleted(dragLayout, dragObject, true)
+        verify(folder, times(0)).replaceFolderWithFinalItem()
+        assertEquals(folder.deleteFolderOnDropCompleted, false)
+    }
+
+    companion object {
+        const val TWO_ICON_FOLDER_TYPE = 'A'
+    }
+}