Fix formatting and printing of help of bisect_perf_regression.py.

BUG=457024

Review URL: https://codereview.chromium.org/916503002

Cr-Commit-Position: refs/heads/master@{#315638}

2 files changed, 11 insertions, 7 deletions

diff --git a/tools/auto_bisect/bisect_perf_regression.py b/tools/auto_bisect/bisect_perf_regression.py
index d60f29f3..e4d876f 100755
--- a/tools/auto_bisect/bisect_perf_regression.py
+++ b/tools/auto_bisect/bisect_perf_regression.py
@@ -2578,10 +2578,9 @@ class BisectOptions(object):
                             ' --max_time_minutes. Values will be clamped to '
                             'range [1, 60]. Default value is 20.')
     group.add_argument('-t', '--truncate_percent', type=int, default=25,
-                       help='The highest/lowest % are discarded to form a '
-                            'truncated mean. Values will be clamped to range '
-                            '[0, 25]. Default value is 25 (highest/lowest 25% '
-                            'will be discarded).')
+                       help='The highest/lowest percent are discarded to form '
+                            'a truncated mean. Values will be clamped to range '
+                            '[0, 25]. Default value is 25 percent.')
     group.add_argument('--bisect_mode', default=bisect_utils.BISECT_MODE_MEAN,
                        choices=[bisect_utils.BISECT_MODE_MEAN,
                                 bisect_utils.BISECT_MODE_STD_DEV,
@@ -2670,9 +2669,9 @@ class BisectOptions(object):
     """Creates a parser with bisect options.
 
     Returns:
-      An instance of optparse.OptionParser.
+      An instance of argparse.ArgumentParser.
     """
-    usage = ('%prog [options] [-- chromium-options]\n'
+    usage = ('%(prog)s [options] [-- chromium-options]\n'
              'Perform binary search on revision history to find a minimal '
              'range of revisions where a performance metric regressed.\n')
 
diff --git a/tools/auto_bisect/bisect_perf_regression_test.py b/tools/auto_bisect/bisect_perf_regression_test.py
index f45516a..bd49d8a 100644
--- a/tools/auto_bisect/bisect_perf_regression_test.py
+++ b/tools/auto_bisect/bisect_perf_regression_test.py
@@ -197,6 +197,12 @@ class BisectPerfRegressionTest(unittest.TestCase):
   def tearDown(self):
     os.chdir(self.cwd)
 
+  def testBisectOptionsCanPrintHelp(self):
+    """Tests that the argument parser can be made and can print help."""
+    bisect_options = bisect_perf_regression.BisectOptions()
+    parser = bisect_options._CreateCommandLineParser()
+    parser.format_help()
+
   def testParseDEPSStringManually(self):
     """Tests DEPS parsing."""
     deps_file_contents = """
@@ -665,4 +671,3 @@ class GitTryJobTestCases(unittest.TestCase):
 
 if __name__ == '__main__':
   unittest.main()
-