Add a webkit-patch command which gets a list of relevant try jobs.

third_party/WebKit/Tools/Scripts/webkitpy/common/net/rietveld.py

Index: third_party/WebKit/Tools/Scripts/webkitpy/common/net/rietveld.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/common/net/rietveld.py b/third_party/WebKit/Tools/Scripts/webkitpy/common/net/rietveld.py
new file mode 100644
index 0000000000000000000000000000000000000000..bc4bdbf84a94f924a1f79493bb3095b98a0f9ea7
--- /dev/null
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/common/net/rietveld.py
@@ -0,0 +1,60 @@
+# Copyright 2016 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.
+
+"""Utility functions to communicate with Rietveld."""
+
+import collections
+import json
+
+
+TryJob = collections.namedtuple('TryJob', ('builder_name', 'master_name', 'build_number'))
+
+
+def latest_try_jobs(issue_number, builder_names, web, patchset_number=None):
+    """Returns a list of TryJob objects for jobs on the latest patchset.
+
+    Args:
+        issue_number: A Rietveld issue number.
+        builder_names: Builders that we're interested in; try jobs for only
+            these builders will be listed.
+        web: webkitpy.common.net.web.Web object (which can be mocked out).
+        patchset_number: Use a specific patchset instead of the latest one.
+
+    Returns:
+        A list of TryJob objects.
+    """
+    if patchset_number:
+        url = _patchset_url(issue_number, patchset_number)
+    else:
+        url = _latest_patchset_url(issue_number, web)
+    patchset_data = _get_json(url, web)
+    assert 'try_job_results' in patchset_data
+    jobs = []
+    for job in patchset_data['try_job_results']:
+        if job['builder'] not in builder_names:
+            continue
+        jobs.append(TryJob(
+            builder_name=job['builder'],
+            master_name=job['master'],
+            build_number=job['buildnumber']))
+    return jobs
+
+
+def _latest_patchset_url(issue_number, web):
+    issue_data = _get_json(_issue_url(issue_number), web)
+    latest_patchset_number = issue_data["patchsets"][-1]
+    return _patchset_url(issue_number, latest_patchset_number)
+
+
+def _get_json(url, web):
+    assert not isinstance(web, tuple), web

[qyearsley, 2016/06/15 21:34:15]

Note, this was a debugging statement, removing now.

+    return json.loads(web.get_binary(url))

[wkorman, 2016/06/15 17:43:17]

Maybe catch error and deal gracefully, returning empty string or otherwise?

https://cs.chromium.org/chromium/src/third_party/WebKit/Tools/Scripts/webkitp...

It looks like we don't do that elsewhere currently, for example:

https://cs.chromium.org/chromium/src/third_party/WebKit/Tools/Scripts/webkitp...

but perhaps now is a good time to start vs full stack trace killing the script.
You know what they say about error codes, Always Be Checking, or somesuch.
Thoughts?

[qyearsley, 2016/06/15 21:34:15]

Advantages of catching errors and printing error messages:
 - It's clearer to the user what happened when the response from Rietveld is
wrong.
 - More explicit.

Advantages of leaving it with no error checking:
 - Code is slightly less simple.
 - The program will terminate immediately after receiving a bad response, which
is likely what we want to happen in this case.

In the latest patchset, I've now made it so:
 - _get_json may log error messages (including URL or response contents that
failed)
 - these errors are handled and latest_try_jobs returns an empty list in the
case of any errors.


Any thoughts? Is it too verbose, or is it OK?

[wkorman, 2016/06/22 01:22:44]

Looks ok to me, there are a few other places in webkitpy that check
urllib2.URLError and they're roughly similar.

+
+
+def _issue_url(issue_number):
+    return 'https://codereview.chromium.org/api/%s' % issue_number

[wkorman, 2016/06/15 17:43:17]

Perhaps move string to BASE_CODEREVIEW_URL constant as file or method constant

[qyearsley, 2016/06/15 21:34:15]

Done.

+
+
+def _patchset_url(issue_number, patchset_number):
+    return '%s/%s' % (_issue_url(issue_number), patchset_number)