From a09e3c09832912c649e343b8486e0951457551f7 Mon Sep 17 00:00:00 2001
From: JW Wang <wangchun@google.com>
Date: Tue, 24 Mar 2020 16:09:58 +0800
Subject: [PATCH] Fix a flaky test

It is possible to have multiple committed rollbacks which include the
same app.

Uninstalling an app will delete committed rollbacks which include
the app. However, there is a race condition between when the app is
uninstalled and when rollback manager deletes the rollback as is stated
here:

https://cs.corp.google.com/android/frameworks/base/tests/RollbackTest/RollbackTest/src/com/android/tests/rollback/RollbackTest.java?rcl=75dfeca3d40624b745f41155aa38bc5e3fa405fe&l=116

We hit the assertion in #getUniqueRollbackInfoForPackage when there are
multiple rollbacks including the same package which is caused by the
race condition above.

Let's rewrite the code by calling #hasRollbackInclude instead which will
not throw.

Also do some cleanup in the xml to improve the isolation of our tests.

Bug: 152271716
Test: atest RollbackTest
Change-Id: Iad3effe52db2a0d2d5e3914bcd08ed93926f3fd3
---
 tests/RollbackTest/RollbackTest.xml                |  4 ++++
 .../com/android/tests/rollback/RollbackTest.java   | 14 ++++++++------
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/tests/RollbackTest/RollbackTest.xml b/tests/RollbackTest/RollbackTest.xml
index 269cec1ccca9b..7b85cc84f1f58 100644
--- a/tests/RollbackTest/RollbackTest.xml
+++ b/tests/RollbackTest/RollbackTest.xml
@@ -23,6 +23,10 @@
         <option name="run-command" value="am broadcast -a 'com.google.android.gms.phenotype.FLAG_OVERRIDE' --es package &quot;com.google.android.gms.platformconfigurator&quot; --es user '\\*' --esa flags &quot;ModuleConfig__versioned_immediate_commit_packages&quot; --esa types &quot;bytes&quot; --esa values &quot;Cm5vdGFwYWNrYWdlOgA=&quot; com.google.android.gms" />
         <option name="teardown-command" value="am broadcast -a 'com.google.android.gms.phenotype.FLAG_OVERRIDE' --es action delete --es package &quot;com.google.android.gms.platformconfigurator&quot; --es user '\*' --esa flag &quot;ModuleConfig__immediate_commit_packages&quot; com.google.android.gms" />
         <option name="teardown-command" value="am broadcast -a 'com.google.android.gms.phenotype.FLAG_OVERRIDE' --es action delete --es package &quot;com.google.android.gms.platformconfigurator&quot; --es user '\*' --esa flag &quot;ModuleConfig__versioned_immediate_commit_packages&quot; com.google.android.gms" />
+        <option name="run-command" value="pm uninstall com.android.cts.install.lib.testapp.A" />
+        <option name="run-command" value="pm uninstall com.android.cts.install.lib.testapp.B" />
+        <option name="teardown-command" value="pm uninstall com.android.cts.install.lib.testapp.A" />
+        <option name="teardown-command" value="pm uninstall com.android.cts.install.lib.testapp.B" />
     </target_preparer>
     <test class="com.android.tradefed.testtype.AndroidJUnitTest" >
         <option name="package" value="com.android.tests.rollback" />
diff --git a/tests/RollbackTest/RollbackTest/src/com/android/tests/rollback/RollbackTest.java b/tests/RollbackTest/RollbackTest/src/com/android/tests/rollback/RollbackTest.java
index 5a92d68494342..cab8b4258bc85 100644
--- a/tests/RollbackTest/RollbackTest/src/com/android/tests/rollback/RollbackTest.java
+++ b/tests/RollbackTest/RollbackTest/src/com/android/tests/rollback/RollbackTest.java
@@ -75,6 +75,12 @@ public class RollbackTest {
     private static final String PROPERTY_ENABLE_ROLLBACK_TIMEOUT_MILLIS =
             "enable_rollback_timeout";
 
+    private static boolean hasRollbackInclude(List<RollbackInfo> rollbacks, String packageName) {
+        return rollbacks.stream().anyMatch(
+                ri -> ri.getPackages().stream().anyMatch(
+                        pri -> packageName.equals(pri.getPackageName())));
+    }
+
     /**
      * Test basic rollbacks.
      */
@@ -113,18 +119,14 @@ public class RollbackTest {
             // Uninstall TestApp.A
             Uninstall.packages(TestApp.A);
             assertThat(InstallUtils.getInstalledVersion(TestApp.A)).isEqualTo(-1);
-            // TODO: There is currently a race condition between when the app is
-            // uninstalled and when rollback manager deletes the rollback. Fix it
-            // so that's not the case!
             for (int i = 0; i < 5; ++i) {
-                RollbackInfo rollback = getUniqueRollbackInfoForPackage(
-                        rm.getRecentlyCommittedRollbacks(), TestApp.A);
-                if (rollback != null) {
+                if (hasRollbackInclude(rm.getRecentlyCommittedRollbacks(), TestApp.A)) {
                     Log.i(TAG, "Sleeping 1 second to wait for uninstall to take effect.");
                     Thread.sleep(1000);
                 }
             }
 
+            assertThat(hasRollbackInclude(rm.getRecentlyCommittedRollbacks(), TestApp.A)).isFalse();
             // The app should not be available for rollback.
             waitForUnavailableRollback(TestApp.A);