Merge "Verifying that workspace looks correct at the end of the test." into main

tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java

@@ -16,11 +16,9 @@
 package com.android.launcher3.ui;
 
 import static androidx.test.InstrumentationRegistry.getInstrumentation;
-
 import static com.android.launcher3.testing.shared.TestProtocol.ICON_MISSING;
 import static com.android.launcher3.ui.TaplTestsLauncher3.getAppPackageName;
 import static com.android.launcher3.util.Executors.MAIN_EXECUTOR;
-
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 
@@ -68,6 +66,7 @@ import com.android.launcher3.util.rule.FailureWatcher;
 import com.android.launcher3.util.rule.SamplerRule;
 import com.android.launcher3.util.rule.ScreenRecordRule;
 import com.android.launcher3.util.rule.ShellCommandRule;
+import com.android.launcher3.util.rule.TestIsolationRule;
 import com.android.launcher3.util.rule.TestStabilityRule;
 import com.android.launcher3.util.rule.ViewCaptureRule;
 
@@ -206,7 +205,8 @@ public abstract class AbstractLauncherUiTest {
         final RuleChain inner = RuleChain
                 .outerRule(new PortraitLandscapeRunner(this))
                 .around(new FailureWatcher(mLauncher, viewCaptureRule::getViewCaptureData))
-                .around(viewCaptureRule);
+                .around(viewCaptureRule)
+                .around(new TestIsolationRule(mLauncher));
 
         return TestHelpers.isInLauncherProcess()
                 ? RuleChain.outerRule(ShellCommandRule.setDefaultLauncher()).around(inner)

tests/src/com/android/launcher3/util/rule/TestIsolationRule.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 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 com.android.launcher3.util.rule;
+
+import androidx.annotation.NonNull;
+
+import com.android.launcher3.tapl.LauncherInstrumentation;
+
+import org.junit.rules.TestRule;
+import org.junit.runner.Description;
+import org.junit.runners.model.Statement;
+
+/**
+ * Isolates tests from some of the state created by the previous test.
+ */
+public class TestIsolationRule implements TestRule {
+    final LauncherInstrumentation mLauncher;
+
+    public TestIsolationRule(LauncherInstrumentation launcher) {
+        mLauncher = launcher;
+    }
+
+    @NonNull
+    @Override
+    public Statement apply(@NonNull Statement base, @NonNull Description description) {
+        return new Statement() {
+            @Override
+            public void evaluate() throws Throwable {
+                base.evaluate();
+                // Make sure that Launcher workspace looks correct.
+                mLauncher.goHome();
+            }
+        };
+    }
+}