Bug 1273634 - [mozlint] Add a treeherder formatter, r=jgraham

This is a really simple and ugly formatter that is compatible with
treeherder's error highlighting mechanism. It is designed to be identical
to the current eslint output on treeherder:
https://dxr.mozilla.org/mozilla-central/rev/4d63dde701b47b8661ab7990f197b6b60e543839/tools/lint/eslint-formatter.js

Eventually eslint will also use this and we can remove that file. Once
bug 1276486 is fixed, we can make this look a little nicer. But for now
it gets the job done.

MozReview-Commit-ID: CwfWPcwWFxF

--HG--
extra : transplant_source : %F3PJ%CB%27%A5%82U%D2%CF%B3%9E%A7%9F%0F%A4%F4%E9%5D%BB

python/mozlint/mozlint/formatters/__init__.py

@@ -6,6 +6,7 @@ import json
 
 from ..result import ResultEncoder
 from .stylish import StylishFormatter
+from .treeherder import TreeherderFormatter
 
 
 class JSONFormatter(object):
@@ -16,6 +17,7 @@ class JSONFormatter(object):
 all_formatters = {
     'json': JSONFormatter,
     'stylish': StylishFormatter,
+    'treeherder': TreeherderFormatter,
 }
 
 

python/mozlint/mozlint/formatters/treeherder.py

@@ -0,0 +1,30 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+from __future__ import unicode_literals
+
+from ..result import ResultContainer
+
+
+class TreeherderFormatter(object):
+    """Formatter for treeherder friendly output.
+
+    This formatter looks ugly, but prints output such that
+    treeherder is able to highlight the errors and warnings.
+    This is a stop-gap until bug 1276486 is fixed.
+    """
+    fmt = "TEST-UNEXPECTED-{level} | {path}:{lineno}:{column} | {message} ({rule})"
+
+    def __call__(self, result):
+        message = []
+        for path, errors in sorted(result.iteritems()):
+            for err in errors:
+                assert isinstance(err, ResultContainer)
+
+                d = {s: getattr(err, s) for s in err.__slots__}
+                d['level'] = d['level'].upper()
+                d['rule'] = d['rule'] or d['linter']
+                message.append(self.fmt.format(**d))
+
+        return "\n".join(message)

python/mozlint/mozlint/roller.py

@@ -42,7 +42,7 @@ def _run_linters(queue, paths, **lintargs):
         func = supported_types[linter['type']]
         res = func(paths, linter, **lintargs) or []
 
-        if isinstance(res, basestring):
+        if not isinstance(res, (list, tuple)):
             continue
 
         for r in res:

python/mozlint/test/test_formatters.py

@@ -68,6 +68,16 @@ d/e/f.txt
         fmt = formatters.get('stylish', disable_colors=True)
         self.assertEqual(expected, fmt(self.results))
 
+    def test_treeherder_formatter(self):
+        expected = """
+TEST-UNEXPECTED-ERROR | a/b/c.txt:1:1 | oh no foo (foo)
+TEST-UNEXPECTED-ERROR | a/b/c.txt:4:1 | oh no baz (baz)
+TEST-UNEXPECTED-WARNING | d/e/f.txt:4:2 | oh no bar (bar-not-allowed)
+""".strip()
+
+        fmt = formatters.get('treeherder')
+        self.assertEqual(expected, fmt(self.results))
+
     def test_json_formatter(self):
         fmt = formatters.get('json')
         formatted = json.loads(fmt(self.results))

tools/lint/flake8.lint

@@ -74,7 +74,7 @@ def lint(files, **lintargs):
 
     if not binary:
         print(FLAKE8_NOT_FOUND)
-        return 1
+        return []
 
     cmdargs = [
         binary,