presubmit: Print executed command along with test name.

Useful when runnig the same test both on Python 2 and Python 3.

Change-Id: I6074e4cbd64318985cf438a2d491182b7b9ccc7b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1913259
Reviewed-by: Anthony Polito <apolito@google.com>
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>

presubmit_support.py

@@ -181,21 +181,18 @@ class ThreadPool(object):
       p = subprocess.Popen(cmd, **test.kwargs)
       stdout, _ = sigint_handler.wait(p, test.stdin)
       duration = time.time() - start
-    except OSError as e:
+    except Exception:
       duration = time.time() - start
       return test.message(
-          '%s exec failure (%4.2fs)\n   %s' % (test.name, duration, e))
-    except Exception as e:
-      duration = time.time() - start
-      return test.message(
-          '%s exec failure (%4.2fs)\n%s' % (
-              test.name, duration, traceback.format_exc()))
+          '%s\n%s exec failure (%4.2fs)\n%s' % (
+              test.name, ' '.join(cmd), duration, traceback.format_exc()))
 
     if p.returncode != 0:
       return test.message(
-          '%s (%4.2fs) failed\n%s' % (test.name, duration, stdout))
+          '%s\n%s (%4.2fs) failed\n%s' % (
+              test.name, ' '.join(cmd), duration, stdout))
     if test.info:
-      return test.info('%s (%4.2fs)' % (test.name, duration))
+      return test.info('%s\n%s (%4.2fs)' % (test.name, ' '.join(cmd), duration))
 
   def AddTests(self, tests, parallel=True):
     if parallel:

tests/presubmit_unittest.py

@@ -2063,7 +2063,9 @@ the current line as well!
     self.assertEqual(len(results), 1)
     self.assertEqual(results[0].__class__,
                       presubmit.OutputApi.PresubmitNotifyResult)
-    self.assertEqual('test_module (0.00s) failed\nfoo', results[0]._message)
+    self.assertEqual(
+        'test_module\npyyyyython -m test_module (0.00s) failed\nfoo',
+        results[0]._message)
 
   def testRunPythonUnitTestsFailureCommitting(self):
     input_api = self.MockInputApi(None, True)
@@ -2074,7 +2076,9 @@ the current line as well!
         input_api, presubmit.OutputApi, ['test_module'])
     self.assertEqual(len(results), 1)
     self.assertEqual(results[0].__class__, presubmit.OutputApi.PresubmitError)
-    self.assertEqual('test_module (0.00s) failed\nfoo', results[0]._message)
+    self.assertEqual(
+        'test_module\npyyyyython -m test_module (0.00s) failed\nfoo',
+        results[0]._message)
 
   def testRunPythonUnitTestsSuccess(self):
     input_api = self.MockInputApi(None, False)
@@ -2943,10 +2947,12 @@ class ThreadPoolTest(unittest.TestCase):
 
     self.assertEqual(3, len(messages))
     self.assertIn(
-      '3 exec failure (0.00s)\nTraceback (most recent call last):',
+      '3\n3 exec failure (0.00s)\nTraceback (most recent call last):',
       messages[0])
-    self.assertEqual('4 exec failure (0.00s)\n   OSError', messages[1])
-    self.assertEqual('5 (0.00s) failed\nstdout', messages[2])
+    self.assertIn(
+      '4\n4 exec failure (0.00s)\nTraceback (most recent call last):',
+      messages[1])
+    self.assertEqual('5\n5 (0.00s) failed\nstdout', messages[2])
 
 
 if __name__ == '__main__':