[Android] Improve error messaging for amp failures.

build/android/pylib/remote/device/remote_device_test_run.py

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Run specific test on specific environment."""
 
 import json
 import logging
 import os
 import re
@@ skipping 352 matching lines @@
       if any(_DEVICE_OFFLINE_RE.search(l) for l in adb_trace_log.splitlines()):
         return True
     return False
 
   def _DetectPlatformErrors(self, results):
     if not self._results['results']['pass']:
       if any(_SHORT_MSG_RE.search(l)
           for l in self._results['results']['output'].splitlines()):
         self._LogLogcat()
         for line in self._results['results']['output'].splitlines():
+          if _SHORT_MSG_RE.search(line):

[mikecase (-- gone --), 2015/08/24 19:53:32]

My one comment is that you have the line ...

      if any(_SHORT_MSG_RE.search(l)
          for l in self._results['results']['output'].splitlines()):

above and its a tiny bit confusing why you have to search for _SHORT_MSG_RE
twice.

Could you do something along the lines of what I wrote below. (EDIT: now that I
wrote this out, idk if its actually any clearer  :/)

output_lines = self._results['results']['output'].splitlines()
short_error_messages  = [l for l in output_lines if _SHORT_MSG_RE.search(l)]
long_error_messages  = [l for l in output_lines if _LONG_MSG_RE.search(l)]

if short_error_messages:
  self._LogLogcat()
  # If there is a long message, use that instead.
  if long_messages:
    result_message = long_error_messages[0].split('=')[1]
  else:
    result_message = short_error_messages[0].split('=')[1]
  results.AddResult(result_message, base_test_result.ResultType.CRASH))

[rnephew (Reviews Here), 2015/08/24 20:32:51]

Lets let John chime in and see which he likes better, or if there is a third way
he likes more.

[jbudorick, 2015/09/08 18:21:02]

I think both are doing too much looping & regex searching and would prefer
something like:

_LONG_MSG_RE = re.compile(r'longMsg=(.*)$')
_SHORT_MSG_RE = re.compile(r'shortMsg=(.*)$')

crash_msg = None
for line in self._results['results']['output'].splitlines():
  m = _LONG_MSG_RE.search(line):
  if m:
    crash_msg = m.group(1)
    break

  m = _SHORT_MSG_RE.search(line)
  if m:
    crash_msg = m.group(1)

if crash_msg:
  self._LogLogcat()
  results.AddResult(...)
elif self._DidDeviceGoOffline():
  ...
else:
  ...

[rnephew (Reviews Here), 2015/09/08 19:05:17]

Done.

+            short_msg = line
           if _LONG_MSG_RE.search(line):
             results.AddResult(base_test_result.BaseTestResult(
                 line.split('=')[1], base_test_result.ResultType.CRASH))
             break
         else:
+          # Long message not found, use short message.
           results.AddResult(base_test_result.BaseTestResult(
-              'Unknown platform error detected.',
-              base_test_result.ResultType.UNKNOWN))
+              short_msg.split('=')[1], base_test_result.ResultType.CRASH))
       elif self._DidDeviceGoOffline():
         self._LogLogcat()
         self._LogAdbTraceLog()
         raise remote_device_helper.RemoteDeviceError(
             'Remote service unable to reach device.', is_infra_error=True)
       else:
-        results.AddResult(base_test_result.BaseTestResult(
-            'Remote Service detected error.',
-            base_test_result.ResultType.UNKNOWN))
+        # Remote service is reporting a failure, but no failure in results obj.
+        if results.DidRunPass():
+          results.AddResult(base_test_result.BaseTestResult(
+              'Remote Service detected error.',
+              base_test_result.ResultType.UNKNOWN))