Add JSON check in tools/perf presubmit script.

Add JSON check in tools/perf presubmit script.

BUG=

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=260430

[qyearsley, 2014-03-27 20:54:22]

As mentioned, a presubmit check for seeing whether JSON files are valid. Not
sure if this is exactly the best way to add a check in a presubmit script.

Just tested it out quickly; seems to work.

[tonyg, 2014-03-27 21:09:21]

lgtm

https://codereview.chromium.org/215443002/diff/40001/tools/perf/PRESUBMIT.py
File tools/perf/PRESUBMIT.py (right):

https://codereview.chromium.org/215443002/diff/40001/tools/perf/PRESUBMIT.py#...
tools/perf/PRESUBMIT.py:18: 'E1101',  # Non-existent member is accessed.
I love how you add comments like this, so useful.

https://codereview.chromium.org/215443002/diff/40001/tools/perf/PRESUBMIT.py#...
tools/perf/PRESUBMIT.py:47: return [output_api.PresubmitError('Error parsing
JSON in %s!' % filename)]
I suspect we are swallowing some useful information contained in the ValueError.
We should print that out too.

[qyearsley, 2014-03-27 21:31:57]

https://codereview.chromium.org/215443002/diff/40001/tools/perf/PRESUBMIT.py
File tools/perf/PRESUBMIT.py (right):

https://codereview.chromium.org/215443002/diff/40001/tools/perf/PRESUBMIT.py#...
tools/perf/PRESUBMIT.py:18: 'E1101',  # Non-existent member is accessed.
On 2014/03/27 21:09:21, tonyg wrote:
> I love how you add comments like this, so useful.

Thanks :-)

https://codereview.chromium.org/215443002/diff/40001/tools/perf/PRESUBMIT.py#...
tools/perf/PRESUBMIT.py:47: return [output_api.PresubmitError('Error parsing
JSON in %s!' % filename)]
On 2014/03/27 21:09:21, tonyg wrote:
> I suspect we are swallowing some useful information contained in the
ValueError.
> We should print that out too.

I think that the ValueError that's raised when json.load fails just contains a
string 'No JSON object could be decoded', with no info about line number or
such, so I think it's fine to ignore that here.

[qyearsley, 2014-03-27 21:32:02]

The CQ bit was checked by qyearsley@chromium.org

[commit-bot: I haz the power, 2014-03-27 21:36:11]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/qyearsley@chromium.org/215443002/40001

[cmp, 2014-03-30 16:15:32]

The CQ bit was unchecked by cmp@chromium.org

[cmp, 2014-03-30 16:16:46]

The CQ bit was checked by cmp@chromium.org

[cmp, 2014-03-30 16:17:23]

The CQ bit was unchecked by cmp@chromium.org

[cmp, 2014-03-30 16:19:47]

The CQ bit was checked by cmp@chromium.org

[commit-bot: I haz the power, 2014-03-30 16:19:48]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/qyearsley@chromium.org/215443002/40001

[commit-bot: I haz the power, 2014-03-30 16:52:22]

Change committed as 260430