Child classes can prevent echoing test results.

Summary:
We changed our Facebook implementation to echo test results while the
tests are running. We do not want to echo the test results twice.

Test Plan:
Tested that implementing the function in PhutilUnitTestEngine and
returning true showed the results and returning false didn't show the
results.

Reviewed By: epriestley
Reviewers: jungejason, epriestley, grglr, slawekbiel
Commenters: slawekbiel, aran
CC: sgrimm, slawekbiel, aran, tuomaspelkonen, epriestley
Differential Revision: 400

src/unit/engine/base/ArcanistBaseUnitTestEngine.php

@@ -71,4 +71,14 @@ abstract class ArcanistBaseUnitTestEngine {
   public function setDifferentialDiffID($id) {
     $this->diffID = $id;
   }
+
+  /**
+   * Modify the return value of this function in the child class, if
+   * you do not need to echo the test results after all the tests have
+   * been run. This is the case for example when the child class
+   * prints the tests results while the tests are running.
+   */
+  public function shouldEchoTestResults() {
+    return true;
+  }
 }

src/workflow/unit/ArcanistUnitWorkflow.php

@@ -122,9 +122,13 @@ EOTEXT
       if ($result_code == ArcanistUnitTestResult::RESULT_POSTPONED) {
         $postponed_count++;
       } else {
+        if ($this->engine->shouldEchoTestResults()) {
           echo '  '.$status_codes[$result_code].' '.$result->getName()."\n";
+        }
         if ($result_code != ArcanistUnitTestResult::RESULT_PASS) {
+          if ($this->engine->shouldEchoTestResults()) {
             echo $result->getUserData()."\n";
+          }
           $unresolved[] = $result;
         }
       }