Add test for DisposableComposePanel state

compose/ui/ui/src/desktopTest/kotlin/androidx/compose/ui/awt/DisposableComposePanelTest.kt

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2023 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 androidx.compose.ui.awt
+
+import androidx.compose.runtime.*
+import java.awt.GraphicsEnvironment
+import javax.swing.JFrame
+import kotlin.test.assertEquals
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.runBlocking
+import org.jetbrains.skiko.MainUIDispatcher
+import org.junit.Assume
+import org.junit.Test
+
+class DisposableComposePanelTest {
+    @OptIn(ExperimentalComposeApi::class)
+    @Test
+    fun `compose state shouldn't reset on panel remove and add`() {
+        Assume.assumeFalse(GraphicsEnvironment.getLocalGraphicsEnvironment().isHeadlessInstance)
+
+        runBlocking(MainUIDispatcher) {
+            var initialStateCounter = 0
+            val composePanel = DisposableComposePanel()
+            composePanel.setContent {
+                var state by remember { mutableStateOf(0) }
+
+                LaunchedEffect(state) {
+                    if (state == 0) {
+                        state++
+                        initialStateCounter++
+                    }
+                }
+            }
+
+            val frame = JFrame()
+            try {
+                frame.contentPane.add(composePanel)
+                frame.isUndecorated = true
+
+                frame.pack()
+
+                frame.isVisible = true
+                delay(1000)
+                assertEquals(1, initialStateCounter)
+
+                frame.contentPane.remove(composePanel)
+                delay(1000)
+                assertEquals(1, initialStateCounter)
+
+                frame.contentPane.add(composePanel)
+                delay(1000)
+                assertEquals(1, initialStateCounter)
+            } finally {
+                composePanel.dispose()
+                frame.dispose()
+            }
+        }
+    }
+}