js_checker.py: Restore smoke tests for linting violations.

tools/web_dev_style/js_checker.py

 # Copyright (c) 2012 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.
 
 """Presubmit script for Chromium JS resources.
 
 See chrome/browser/PRESUBMIT.py
 """
 
 import regex_check
@@ skipping 44 matching lines @@
   def InheritDocCheck(self, i, line):
     """Checks for use of '@inheritDoc' instead of '@override'."""
     return self.RegexCheck(i, line, r"\* (@inheritDoc)",
         "@inheritDoc is deprecated, use @override instead")
 
   def PolymerLocalIdCheck(self, i, line):
     """Checks for use of element.$.localId."""
     return self.RegexCheck(i, line, r"(?<!this)(\.\$)[\[\.]",
         "Please only use this.$.localId, not element.$.localId")
 
-  def RunEsLintChecks(self, affected_js_files):
+  def RunEsLintChecks(self, affected_js_files_paths, format='stylish'):
     """Runs lint checks using ESLint. The ESLint rules being applied are defined
        in the .eslintrc.js configuration file.
     """
-    os_path = self.input_api.os_path
-
     try:
       # Import ESLint.
+      os_path = self.input_api.os_path
       _HERE_PATH = os_path.dirname(os_path.realpath(__file__))
       _SRC_PATH = os_path.normpath(os_path.join(_HERE_PATH, '..', '..'))
       import sys
       old_sys_path = sys.path[:]
       sys.path.append(os_path.join(_SRC_PATH, 'third_party', 'node'))
       import node, node_modules
     finally:
       sys.path = old_sys_path
 
-    # Extract paths to be passed to ESLint.
-    affected_js_files_paths = []
-    presubmit_path = self.input_api.PresubmitLocalPath()
-    for f in affected_js_files:
-      affected_js_files_paths.append(
-          os_path.relpath(f.AbsoluteLocalPath(), presubmit_path))
-
     output = node.RunNode([
         node_modules.PathToEsLint(),
         '--color',
+        '--format', format,
         '--ignore-pattern \'!.eslintrc.js\'',
         ' '.join(affected_js_files_paths)])
 
     return [self.output_api.PresubmitError(output)] if output else []
 
   def WrapperTypeCheck(self, i, line):
     """Check for wrappers (new String()) instead of builtins (string)."""
     return self.RegexCheck(i, line,
         r"(?:/\*)?\*.*?@(?:param|return|type) ?"     # /** @param/@return/@type
         r"{[^}]*\b(String|Boolean|Number)\b[^}]*}",  # {(Boolean|Number|String)}
@@ skipping 15 matching lines @@
     """Check for violations of the Chromium JavaScript style guide. See
        https://chromium.googlesource.com/chromium/src/+/master/styleguide/web/web.md#JavaScript
     """
     results = []
 
     affected_files = self.input_api.AffectedFiles(file_filter=self.file_filter,
                                                   include_deletes=False)
     affected_js_files = filter(lambda f: f.LocalPath().endswith('.js'),
                                affected_files)
 
+    # Extract paths to be passed to ESLint.
+    def get_path(f):
+      return os_path.relpath(
+          f.AbsoluteLocalPath(), self.input_api.PresubmitLocalPath())
+
     if affected_js_files:
-      results += self.RunEsLintChecks(affected_js_files)
+      affected_js_files_paths = map(get_path, affected_js_files)
+      results += self.RunEsLintChecks(affected_js_files_paths)

[dpapad, 2017/05/30 22:11:30]

I had to change the signature of RunEsLintChecks, to be able to directly call it
from tests. The problem is that even though I can setup a mock
input_api.AffectedFiles to return a MockFile instance, the MockFile instance is
useless to ESLint, it needs an actual file.

[Dan Beam, 2017/05/30 23:11:08]

wait, why doesn't this work?
https://cs.chromium.org/chromium/src/PRESUBMIT_test_mocks.py?sq=package:chrom...

[dpapad, 2017/05/31 01:30:06]

Updated the code to use a MockFile().

 
     for f in affected_js_files:
       error_lines = []
 
       for i, line in enumerate(f.NewContents(), start=1):
         error_lines += filter(None, [
             self.ChromeSendCheck(i, line),
             self.CommentIfAndIncludeCheck(i, line),
             self.ConstCheck(i, line),
             self.EndJsDocCommentCheck(i, line),
             self.ExtraDotInGenericCheck(i, line),
             self.InheritDocCheck(i, line),
             self.PolymerLocalIdCheck(i, line),
             self.WrapperTypeCheck(i, line),
             self.VarNameCheck(i, line),
         ])
 
       if error_lines:
         error_lines = [
             'Found JavaScript style violations in %s:' %
             f.LocalPath()] + error_lines
         results.append(self.output_api.PresubmitError('\n'.join(error_lines)))
 
     if results:
       results.append(self.output_api.PresubmitNotifyResult(
           'See the JavaScript style guide at '
           'https://chromium.googlesource.com/chromium/src/+/master/styleguide/web/web.md#JavaScript'))
 
     return results