Add a script that can discover *.isolated files in a directory.

Add a script that can discover *.isolated files in a directory.

It used to live in chromium build tool tree:
chrome/trunk/tools/build/scripts/slave/swarming/manifest_to_hash.py@251882

Directory build/scripts/slave/swarming/ is going away soon (with its
functionality replaced by swarming and isolate recipe modules). So this
script needs a new home.

R=maruel@chromium.org
NOTRY=true
BUG=

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=254198

[Vadim Sh., 2014-02-27 22:40:34]

ptal

[Vadim Sh., 2014-02-28 18:49:53]

ping

[M-A Ruel, 2014-02-28 18:56:04]

Sorry.

https://codereview.chromium.org/180153005/diff/1/build/find_isolated_tests.py
File build/find_isolated_tests.py (right):

https://codereview.chromium.org/180153005/diff/1/build/find_isolated_tests.py...
build/find_isolated_tests.py:40: parser = optparse.OptionParser(usage='%prog
path [options]')
I like description=sys.modules[__name__].__doc__, as you prefer

s/path/<build dir>/

https://codereview.chromium.org/180153005/diff/1/build/find_isolated_tests.py...
build/find_isolated_tests.py:45: parser.error('Missing path.')
s/path/build output directory/

https://codereview.chromium.org/180153005/diff/1/build/find_isolated_tests.py...
build/find_isolated_tests.py:59: if not options.output_json:
If you don't plan to use the --output_json flag, do not write it.

[Vadim Sh., 2014-02-28 19:12:18]

https://codereview.chromium.org/180153005/diff/1/build/find_isolated_tests.py
File build/find_isolated_tests.py (right):

https://codereview.chromium.org/180153005/diff/1/build/find_isolated_tests.py...
build/find_isolated_tests.py:40: parser = optparse.OptionParser(usage='%prog
path [options]')
On 2014/02/28 18:56:04, M-A Ruel wrote:
> I like description=sys.modules[__name__].__doc__, as you prefer
> 
> s/path/<build dir>/

Done.

https://codereview.chromium.org/180153005/diff/1/build/find_isolated_tests.py...
build/find_isolated_tests.py:45: parser.error('Missing path.')
On 2014/02/28 18:56:04, M-A Ruel wrote:
> s/path/build output directory/

Done.

https://codereview.chromium.org/180153005/diff/1/build/find_isolated_tests.py...
build/find_isolated_tests.py:59: if not options.output_json:
On 2014/02/28 18:56:04, M-A Ruel wrote:
> If you don't plan to use the --output_json flag, do not write it.

That is actually exactly what I'm going to use. Maybe remove stdout then and
change cmd line to %prod <build dir> <output json>?

[M-A Ruel, 2014-02-28 19:14:00]

https://codereview.chromium.org/180153005/diff/1/build/find_isolated_tests.py
File build/find_isolated_tests.py (right):

https://codereview.chromium.org/180153005/diff/1/build/find_isolated_tests.py...
build/find_isolated_tests.py:59: if not options.output_json:
On 2014/02/28 19:12:18, Vadim Sh. wrote:
> On 2014/02/28 18:56:04, M-A Ruel wrote:
> > If you don't plan to use the --output_json flag, do not write it.
> 
> That is actually exactly what I'm going to use. Maybe remove stdout then and
> change cmd line to %prod <build dir> <output json>?

Ok. Note that I do like flags in general, so you could use
find_isolated_tests.py --build-dir out/Release --output-json foo.json

This is much more self-explanative at call point than having to figure out which
parameter means what.

[Vadim Sh., 2014-02-28 19:23:20]

https://codereview.chromium.org/180153005/diff/1/build/find_isolated_tests.py
File build/find_isolated_tests.py (right):

https://codereview.chromium.org/180153005/diff/1/build/find_isolated_tests.py...
build/find_isolated_tests.py:59: if not options.output_json:
On 2014/02/28 19:14:00, M-A Ruel wrote:
> On 2014/02/28 19:12:18, Vadim Sh. wrote:
> > On 2014/02/28 18:56:04, M-A Ruel wrote:
> > > If you don't plan to use the --output_json flag, do not write it.
> > 
> > That is actually exactly what I'm going to use. Maybe remove stdout then and
> > change cmd line to %prod <build dir> <output json>?
> 
> Ok. Note that I do like flags in general, so you could use
> find_isolated_tests.py --build-dir out/Release --output-json foo.json
> 
> This is much more self-explanative at call point than having to figure out
which
> parameter means what.

Good idea. Done.

[M-A Ruel, 2014-02-28 19:25:02]

lgtm with 2 less lines. :)

https://codereview.chromium.org/180153005/diff/40001/build/find_isolated_test...
File build/find_isolated_tests.py (right):

https://codereview.chromium.org/180153005/diff/40001/build/find_isolated_test...
build/find_isolated_tests.py:50: build_dir = options.build_dir
why, you want so save space on line 60? I'd personally remove line 53 too. You'd
have to update line 54 and 72.

[Vadim Sh., 2014-02-28 19:30:04]

https://codereview.chromium.org/180153005/diff/40001/build/find_isolated_test...
File build/find_isolated_tests.py (right):

https://codereview.chromium.org/180153005/diff/40001/build/find_isolated_test...
build/find_isolated_tests.py:50: build_dir = options.build_dir
On 2014/02/28 19:25:02, M-A Ruel wrote:
> why, you want so save space on line 60? I'd personally remove line 53 too.
You'd
> have to update line 54 and 72.
Okay.. 'for' line didn't fit into 80 chars (and I dislike splitting 'for' line
into two lines), so overall savings is only 1 line :P

[Vadim Sh., 2014-02-28 19:42:05]

The CQ bit was checked by vadimsh@chromium.org

[commit-bot: I haz the power, 2014-02-28 19:45:00]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/vadimsh@chromium.org/180153005/60001

[commit-bot: I haz the power, 2014-02-28 19:46:55]

Change committed as 254198