Prevent some leaks from leaking to the next test

Now when exiting the test, we finish Launcher activity and force the leak check.
I've seen this helping one of the leaks to stay within the test that caused it instead of failing the next test.

Bug: 187761685
Flag: N/A
Test: presubmit, local
Change-Id: I7eac26f749433c37a6880a2f035ab1ba9c5fef6e
diff --git a/tests/Android.bp b/tests/Android.bp
index 5a52440..ac0749e 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -54,6 +54,7 @@
       "src/com/android/launcher3/util/rule/SamplerRule.java",
       "src/com/android/launcher3/util/rule/ScreenRecordRule.java",
       "src/com/android/launcher3/util/rule/ShellCommandRule.java",
+      "src/com/android/launcher3/util/rule/TestIsolationRule.java",
       "src/com/android/launcher3/util/rule/TestStabilityRule.java",
       "src/com/android/launcher3/util/rule/TISBindRule.java",
       "src/com/android/launcher3/util/viewcapture_analysis/*.java",
diff --git a/tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java b/tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java
index 5240e6a..8fac53d 100644
--- a/tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java
+++ b/tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java
@@ -68,6 +68,7 @@
 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;
 
@@ -123,6 +124,10 @@
                 }, DEFAULT_UI_TIMEOUT, launcher);
     }
 
+    public void checkDetectedLeaks() {
+        checkDetectedLeaks(mLauncher);
+    }
+
     private static String getActivityLeakErrorMessage(LauncherInstrumentation launcher) {
         sActivityLeakReported = true;
         return "Activity leak detector has found leaked activities, "
@@ -215,7 +220,8 @@
 
     @Rule
     public TestRule mOrderSensitiveRules = RuleChain
-            .outerRule(new SamplerRule())
+            .outerRule(new TestIsolationRule(this))
+            .around(new SamplerRule())
             .around(new TestStabilityRule())
             .around(getRulesInsideActivityMonitor());
 
@@ -488,6 +494,12 @@
     }
 
     protected void closeLauncherActivity() {
+        finishLauncherActivity();
+        waitForLauncherCondition(
+                "Launcher still active", launcher -> launcher == null, DEFAULT_UI_TIMEOUT);
+    }
+
+    public void finishLauncherActivity() {
         // Destroy Launcher activity.
         executeOnLauncher(launcher -> {
             if (launcher != null) {
@@ -495,8 +507,6 @@
                 launcher.finish();
             }
         });
-        waitForLauncherCondition(
-                "Launcher still active", launcher -> launcher == null, DEFAULT_UI_TIMEOUT);
     }
 
     protected boolean isInLaunchedApp(Launcher launcher) {
diff --git a/tests/src/com/android/launcher3/util/rule/TestIsolationRule.java b/tests/src/com/android/launcher3/util/rule/TestIsolationRule.java
new file mode 100644
index 0000000..d4bfa6b
--- /dev/null
+++ b/tests/src/com/android/launcher3/util/rule/TestIsolationRule.java
@@ -0,0 +1,53 @@
+/*
+ * 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.ui.AbstractLauncherUiTest;
+
+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 AbstractLauncherUiTest mTest;
+
+    public TestIsolationRule(AbstractLauncherUiTest test) {
+        mTest = test;
+    }
+
+    @NonNull
+    @Override
+    public Statement apply(@NonNull Statement base, @NonNull Description description) {
+        return new Statement() {
+            @Override
+            public void evaluate() throws Throwable {
+                mTest.finishLauncherActivity();
+                mTest.checkDetectedLeaks();
+                try {
+                    base.evaluate();
+                } finally {
+                    mTest.finishLauncherActivity();
+                }
+                mTest.checkDetectedLeaks();
+            }
+        };
+    }
+}