Ensure @Before and @Test run on the same thread in AndroidJUnit4ClassRunner.

runner/android_junit_runner/CHANGELOG.md

@@ -12,6 +12,8 @@
 
 * Add logs at the start and end of RunBefore and RunAfters sections to help bug understanding. (b/445754263)
 
+* Ensure @Before and @Test run on the same thread in AndroidJUnit4ClassRunner.
+
 **Breaking Changes**
 
 **API Changes**

runner/android_junit_runner/java/androidx/test/internal/runner/junit4/AndroidJUnit4ClassRunner.java

@@ -73,31 +73,31 @@ protected Statement withBefores(FrameworkMethod method, Object target, Statement
   @Override
   protected Statement withAfters(FrameworkMethod method, Object target, Statement statement) {
     List<FrameworkMethod> afters = getTestClass().getAnnotatedMethods(After.class);
-    return afters.isEmpty() ? statement : new RunAfters(method, statement, afters, target);
-  }
+    Statement combined =
+        afters.isEmpty() ? statement : new RunAfters(method, statement, afters, target);
 
-  /**
-   * Default to {@link org.junit.Test#timeout()} level timeout if set. Otherwise, set the timeout
-   * that was passed to the instrumentation via argument.
-   */
-  @Override
-  protected Statement withPotentialTimeout(FrameworkMethod method, Object test, Statement next) {
-    // test level timeout i.e @Test(timeout = 123)
     long timeout = getTimeout(method.getAnnotation(Test.class));
-
-    // use runner arg timeout if test level timeout is not present
     if (timeout <= 0 && perTestTimeout > 0) {
       timeout = perTestTimeout;
     }
 
-    if (timeout <= 0) {
-      // no timeout was set
-      return next;
+    if (timeout > 0) {
+      // Cannot switch to use builder as that is not supported in JUnit 4.10 which is what is
+      // available in AOSP.
+      @SuppressWarnings("deprecation")
+      var failOnTimeout = new FailOnTimeout(combined, timeout);
+      return failOnTimeout;
     }
+    return combined;
+  }
 
-    // Cannot switch to use builder as that is not supported in JUnit 4.10 which is what is
-    // available in AOSP.
-    return new FailOnTimeout(next, timeout);
+  /**
+   * Default to {@link org.junit.Test#timeout()} level timeout if set. Otherwise, set the timeout
+   * that was passed to the instrumentation via argument.
+   */
+  @Override
+  protected Statement withPotentialTimeout(FrameworkMethod method, Object test, Statement next) {
+    return next;
   }
 
   private long getTimeout(Test annotation) {