Add assertions to CloseAppBackButtonTest

Adding all the assertions for the CloseAppBackButtonTest. This includes WM assertions (the common ones for all test + one that the launcher replaces the app window and another that the wallpaper window becomes visible) and layers assertions (the common ones + one for the wallpaper layer replacing the app layer).
Also adding new assertions in CommonAssertions files (wallpaperLayerReplacesAppLayer, wallpaperWindowBecomesVisible and launcherReplacesAppWindowAsTopWindow).

Test: atest FlickerTests:CloseAppBackButtonTest
Bug: b/171049647
Change-Id: I992edfe372b677d723dda09a0af8fdf9f6213c73

tests/FlickerTests/src/com/android/server/wm/flicker/CommonAssertions.kt

@@ -16,6 +16,7 @@
 
 package com.android.server.wm.flicker
 
+import android.platform.helpers.IAppHelper
 import com.android.server.wm.flicker.dsl.EventLogAssertion
 import com.android.server.wm.flicker.dsl.LayersAssertion
 import com.android.server.wm.flicker.dsl.WmAssertion
@@ -24,6 +25,7 @@ import com.android.server.wm.flicker.helpers.WindowUtils
 const val NAVIGATION_BAR_WINDOW_TITLE = "NavigationBar"
 const val STATUS_BAR_WINDOW_TITLE = "StatusBar"
 const val DOCKED_STACK_DIVIDER = "DockedStackDivider"
+const val WALLPAPER_TITLE = "Wallpaper"
 
 @JvmOverloads
 fun WmAssertion.statusBarWindowIsAlwaysVisible(
@@ -54,6 +56,29 @@ fun WmAssertion.visibleWindowsShownMoreThanOneConsecutiveEntry(
     }
 }
 
+fun WmAssertion.launcherReplacesAppWindowAsTopWindow(
+    testApp: IAppHelper,
+    bugId: Int = 0,
+    enabled: Boolean = bugId == 0
+) {
+    all("launcherReplacesAppWindowAsTopWindow", bugId, enabled) {
+        this.showsAppWindowOnTop(testApp.getPackage())
+                .then()
+                .showsAppWindowOnTop("Launcher")
+    }
+}
+
+fun WmAssertion.wallpaperWindowBecomesVisible(
+    bugId: Int = 0,
+    enabled: Boolean = bugId == 0
+) {
+    all("wallpaperWindowBecomesVisible", bugId, enabled) {
+        this.hidesBelowAppWindow(WALLPAPER_TITLE)
+                .then()
+                .showsBelowAppWindow(WALLPAPER_TITLE)
+    }
+}
+
 @JvmOverloads
 fun LayersAssertion.noUncoveredRegions(
     beginRotation: Int,
@@ -177,6 +202,18 @@ fun LayersAssertion.visibleLayersShownMoreThanOneConsecutiveEntry(
     }
 }
 
+fun LayersAssertion.wallpaperLayerReplacesAppLayer(
+    testApp: IAppHelper,
+    bugId: Int = 0,
+    enabled: Boolean = bugId == 0
+) {
+    all("appLayerReplacesWallpaperLayer", bugId, enabled) {
+        this.showsLayer(testApp.getPackage())
+                .then()
+                .replaceVisibleLayer(testApp.getPackage(), WALLPAPER_TITLE)
+    }
+}
+
 fun EventLogAssertion.focusChanges(
     vararg windows: String,
     bugId: Int = 0,

tests/FlickerTests/src/com/android/server/wm/flicker/close/CloseAppBackButtonTest.kt

@@ -20,8 +20,21 @@ import android.view.Surface
 import androidx.test.filters.RequiresDevice
 import androidx.test.platform.app.InstrumentationRegistry
 import com.android.server.wm.flicker.Flicker
+import com.android.server.wm.flicker.endRotation
 import com.android.server.wm.flicker.FlickerTestRunnerFactory
 import com.android.server.wm.flicker.FlickerTestRunner
+import com.android.server.wm.flicker.navBarWindowIsAlwaysVisible
+import com.android.server.wm.flicker.statusBarWindowIsAlwaysVisible
+import com.android.server.wm.flicker.navBarLayerIsAlwaysVisible
+import com.android.server.wm.flicker.statusBarLayerIsAlwaysVisible
+import com.android.server.wm.flicker.launcherReplacesAppWindowAsTopWindow
+import com.android.server.wm.flicker.wallpaperWindowBecomesVisible
+import com.android.server.wm.flicker.wallpaperLayerReplacesAppLayer
+import com.android.server.wm.flicker.noUncoveredRegions
+import com.android.server.wm.flicker.navBarLayerRotatesAndScales
+import com.android.server.wm.flicker.statusBarLayerRotatesScales
+import com.android.server.wm.flicker.visibleWindowsShownMoreThanOneConsecutiveEntry
+import com.android.server.wm.flicker.visibleLayersShownMoreThanOneConsecutiveEntry
 import com.android.server.wm.flicker.helpers.wakeUpAndGoToHomeScreen
 import com.android.server.wm.flicker.helpers.StandardAppHelper
 import com.android.server.wm.flicker.helpers.buildTestTag
@@ -34,22 +47,6 @@ import org.junit.runner.RunWith
 import org.junit.runners.MethodSorters
 import org.junit.runners.Parameterized
 
-/*
- * Copyright (C) 2020 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.
- */
-
 /**
  * Test app closes by pressing back button
  * To run this test: `atest FlickerTests:CloseAppBackButtonTest`
@@ -93,6 +90,32 @@ class CloseAppBackButtonTest(
                                 testApp.exit()
                             }
                         }
+                        assertions {
+                            windowManagerTrace {
+                                navBarWindowIsAlwaysVisible()
+                                statusBarWindowIsAlwaysVisible()
+                                visibleWindowsShownMoreThanOneConsecutiveEntry()
+
+                                launcherReplacesAppWindowAsTopWindow(testApp)
+                                wallpaperWindowBecomesVisible()
+                            }
+
+                            layersTrace {
+                                noUncoveredRegions(configuration.startRotation,
+                                        Surface.ROTATION_0, bugId = 141361128)
+                                navBarLayerRotatesAndScales(configuration.startRotation,
+                                        Surface.ROTATION_0)
+                                statusBarLayerRotatesScales(configuration.startRotation,
+                                        Surface.ROTATION_0)
+                                navBarLayerIsAlwaysVisible(
+                                        enabled = Surface.ROTATION_0 == configuration.endRotation)
+                                statusBarLayerIsAlwaysVisible(
+                                        enabled = Surface.ROTATION_0 == configuration.endRotation)
+                                visibleLayersShownMoreThanOneConsecutiveEntry()
+
+                                wallpaperLayerReplacesAppLayer(testApp)
+                            }
+                        }
                     }
         }
     }