Add --unexpected-failures flag to run_mojo_python_tests.

Add --unexpected-failures flag to run_mojo_python_tests.

In order to best run a suite of tests on the bots, we need to support
printing out the list of tests that failed in an easily-machine-readable
manner, and also support running just a subset of tests.

This patch adds the --unexpected-failures flag to run_mojo_python_tests
to write out, one test name per line, a list of failures (full details
are listed in the usage for the script).

It also adds the ability to just run a subset of tests.

If we add any more complexity to this script we really need to write tests
for it.

R=sky@chromium.org
BUG=364709
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=266792

[Dirk Pranke, 2014-04-28 20:16:22]

sorry for the delay on this; it took me a while to find the time to implement
the proper solution so that we can detect failures properly.

[sky, 2014-04-28 20:42:54]

sky->viettrungluu, he actually understands Python where as I just complain about
it.

[viettrungluu, 2014-04-28 21:17:20]

LGTM w/minor comments.

https://codereview.chromium.org/257103002/diff/40001/mojo/tools/run_mojo_pyth...
File mojo/tools/run_mojo_python_tests.py (right):

https://codereview.chromium.org/257103002/diff/40001/mojo/tools/run_mojo_pyth...
mojo/tools/run_mojo_python_tests.py:1: #!/usr/bin/python
I think we mostly use "/usr/bin/env python" (and I previously changed it to
this).

https://codereview.chromium.org/257103002/diff/40001/mojo/tools/run_mojo_pyth...
mojo/tools/run_mojo_python_tests.py:13: def Main():
FWIW, both the Chromium OS and the internal Google Python style guide seem to
prescribe "main" instead of "Main".

https://codereview.chromium.org/257103002/diff/40001/mojo/tools/run_mojo_pyth...
mojo/tools/run_mojo_python_tests.py:17:
parser.add_option('--unexpected-failures', action='store',
Add: metavar='FILENAME' or something like that?

(FWIW, optparse was deprecated in Python 2.7 and replaced by argparse, because
Python programmers love nothing better than writing getopt replacements. I only
mention this because I had to double-check that optparse accepts the metavar
argument....)

[Dirk Pranke, 2014-04-28 21:20:27]

https://codereview.chromium.org/257103002/diff/40001/mojo/tools/run_mojo_pyth...
File mojo/tools/run_mojo_python_tests.py (right):

https://codereview.chromium.org/257103002/diff/40001/mojo/tools/run_mojo_pyth...
mojo/tools/run_mojo_python_tests.py:1: #!/usr/bin/python
On 2014/04/28 21:17:20, viettrungluu wrote:
> I think we mostly use "/usr/bin/env python" (and I previously changed it to
> this).

Hm. I didn't think that was either pervasive or style-guide recommended, but ok.


(it's possible that this patch is based off of an old rev, too).

https://codereview.chromium.org/257103002/diff/40001/mojo/tools/run_mojo_pyth...
mojo/tools/run_mojo_python_tests.py:13: def Main():
On 2014/04/28 21:17:20, viettrungluu wrote:
> FWIW, both the Chromium OS and the internal Google Python style guide seem to
> prescribe "main" instead of "Main".

Ok. I thought it was Main, but I could easily be wrong here.

https://codereview.chromium.org/257103002/diff/40001/mojo/tools/run_mojo_pyth...
mojo/tools/run_mojo_python_tests.py:17:
parser.add_option('--unexpected-failures', action='store',
On 2014/04/28 21:17:20, viettrungluu wrote:
> Add: metavar='FILENAME' or something like that?
> 
> (FWIW, optparse was deprecated in Python 2.7 and replaced by argparse, because
> Python programmers love nothing better than writing getopt replacements. I
only
> mention this because I had to double-check that optparse accepts the metavar
> argument....)

Ok. I can switch to argparse if you'd prefer.

[Dirk Pranke, 2014-04-28 21:26:41]

The CQ bit was checked by dpranke@chromium.org

[commit-bot: I haz the power, 2014-04-28 21:27:59]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dpranke@chromium.org/257103002/60001

[commit-bot: I haz the power, 2014-04-28 21:31:46]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-04-28 21:31:46]

Try jobs failed on following builders:
  tryserver.chromium on linux_chromium_gn_rel

[Dirk Pranke, 2014-04-28 22:39:23]

The CQ bit was checked by dpranke@chromium.org

[commit-bot: I haz the power, 2014-04-28 22:41:19]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dpranke@chromium.org/257103002/60001

[commit-bot: I haz the power, 2014-04-28 23:31:45]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-04-28 23:31:45]

Try jobs failed on following builders:
  tryserver.chromium on linux_chromium_chromeos_rel

[Dirk Pranke, 2014-04-29 00:13:56]

The CQ bit was checked by dpranke@chromium.org

[commit-bot: I haz the power, 2014-04-29 00:16:22]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dpranke@chromium.org/257103002/60001

[commit-bot: I haz the power, 2014-04-29 09:03:14]

Change committed as 266792