fix sender initialization so only one is created

Summary: Sender was being initialized once per class, leading to only the final class's tests reporting results. This moves it to the right spot.

Reviewed By: IanChilds

Differential Revision: D75086195

fbshipit-source-id: 5fef6e49bb85edbb992cd1eca456d765964050a4

Author: Carlos Gomez

prelude/toolchains/android/src/com/facebook/buck/testrunner/JUnitRunner.java

@@ -91,6 +91,10 @@ public void run() throws Throwable {
       stdErrLogLevel = Level.parse(unparsedStdErrLogLevel);
     }
 
+    // TPX sets the env var that enables the Standard Output format
+    Optional<TestResultsOutputSender> testResultsOutputSender =
+        TestResultsOutputSender.fromDefaultEnvName();
+
     for (String className : testClassNames) {
       Class<?> testClass = Class.forName(className);
       Class<?>[] testClasses;
@@ -109,11 +113,6 @@ public void run() throws Throwable {
         request = request.filterWith(filter);
         jUnitCore.addListener(new TestListener(results, stdOutLogLevel, stdErrLogLevel));
 
-        // testResultsOutputSender will only be present if the environment variable is set to use
-        // TPX Standard Output. In that case, we want to add the listener so the test results JSON
-        // file is written.
-        Optional<TestResultsOutputSender> testResultsOutputSender =
-            TestResultsOutputSender.fromDefaultEnvName();
         if (testResultsOutputSender.isPresent()) {
           JUnitTpxStandardOutputListener tpxListener =
               new JUnitTpxStandardOutputListener(testResultsOutputSender.get());