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1# Copyright (c) 2012 The Chromium Authors. All rights reserved.
2# Use of this source code is governed by a BSD-style license that can be
3# found in the LICENSE file.
4
5"""Presubmit script for Chromium JS resources.
6
7See chrome/browser/PRESUBMIT.py
8"""
9
10class JSChecker(object):
11  def __init__(self, input_api, output_api, file_filter=None):
12    self.input_api = input_api
13    self.output_api = output_api
14    self.file_filter = file_filter
15
16  def RegexCheck(self, line_number, line, regex, message):
17    """Searches for |regex| in |line| to check for a particular style
18       violation, returning a message like the one below if the regex matches.
19       The |regex| must have exactly one capturing group so that the relevant
20       part of |line| can be highlighted. If more groups are needed, use
21       "(?:...)" to make a non-capturing group. Sample message:
22
23       line 6: Use var instead of const.
24           const foo = bar();
25           ^^^^^
26    """
27    match = self.input_api.re.search(regex, line)
28    if match:
29      assert len(match.groups()) == 1
30      start = match.start(1)
31      length = match.end(1) - start
32      return '  line %d: %s\n%s\n%s' % (
33          line_number,
34          message,
35          line,
36          self.error_highlight(start, length))
37    return ''
38
39  def ChromeSendCheck(self, i, line):
40    """Checks for a particular misuse of 'chrome.send'."""
41    return self.RegexCheck(i, line, r"chrome\.send\('[^']+'\s*(, \[\])\)",
42        'Passing an empty array to chrome.send is unnecessary')
43
44  def ConstCheck(self, i, line):
45    """Check for use of the 'const' keyword."""
46    if self.input_api.re.search(r'\*\s+@const', line):
47      # Probably a JsDoc line
48      return ''
49
50    return self.RegexCheck(i, line, r'(?:^|\s|\()(const)\s',
51        'Use /** @const */ var varName; instead of const varName;')
52
53  def EndJsDocCommentCheck(self, i, line):
54    msg = 'End JSDoc comments with */ instead of **/'
55    def _check(regex):
56      return self.RegexCheck(i, line, regex, msg)
57    return _check(r'^\s*(\*\*/)\s*$') or _check(r'/\*\* @[a-zA-Z]+.* (\*\*/)')
58
59  def GetElementByIdCheck(self, i, line):
60    """Checks for use of 'document.getElementById' instead of '$'."""
61    return self.RegexCheck(i, line, r"(document\.getElementById)\('",
62        "Use $('id'), from chrome://resources/js/util.js, instead of "
63        "document.getElementById('id')")
64
65  def InheritDocCheck(self, i, line):
66    """Checks for use of '@inheritDoc' instead of '@override'."""
67    return self.RegexCheck(i, line, r"\* (@inheritDoc)",
68        "@inheritDoc is deprecated, use @override instead")
69
70  def WrapperTypeCheck(self, i, line):
71    """Check for wrappers (new String()) instead of builtins (string)."""
72    return self.RegexCheck(i, line,
73        r"(?:/\*)?\*.*?@(?:param|return|type) ?"     # /** @param/@return/@type
74        r"{[^}]*\b(String|Boolean|Number)\b[^}]*}",  # {(Boolean|Number|String)}
75        "Don't use wrapper types (i.e. new String() or @type {String})")
76
77  def VarNameCheck(self, i, line):
78    """See the style guide. http://goo.gl/uKir6"""
79    return self.RegexCheck(i, line,
80        r"var (?!g_\w+)([a-z]*[_$][\w_$]*)(?<! \$)",
81        "Please use var namesLikeThis <http://goo.gl/uKir6>")
82
83  def error_highlight(self, start, length):
84    """Takes a start position and a length, and produces a row of '^'s to
85       highlight the corresponding part of a string.
86    """
87    return start * ' ' + length * '^'
88
89  def _makeErrorOrWarning(self, error_text, filename):
90    """Takes a few lines of text indicating a style violation and turns it into
91       a PresubmitError (if |filename| is in a directory where we've already
92       taken out all the style guide violations) or a PresubmitPromptWarning
93       (if it's in a directory where we haven't done that yet).
94    """
95    # TODO(tbreisacher): Once we've cleaned up the style nits in all of
96    # resources/ we can get rid of this function.
97    path = self.input_api.os_path
98    resources = path.join(self.input_api.PresubmitLocalPath(), 'resources')
99    dirs = (
100        path.join(resources, 'bookmark_manager'),
101        path.join(resources, 'extensions'),
102        path.join(resources, 'file_manager'),
103        path.join(resources, 'help'),
104        path.join(resources, 'history'),
105        path.join(resources, 'memory_internals'),
106        path.join(resources, 'net_export'),
107        path.join(resources, 'net_internals'),
108        path.join(resources, 'network_action_predictor'),
109        path.join(resources, 'ntp4'),
110        path.join(resources, 'options'),
111        path.join(resources, 'password_manager_internals'),
112        path.join(resources, 'print_preview'),
113        path.join(resources, 'profiler'),
114        path.join(resources, 'sync_promo'),
115        path.join(resources, 'tracing'),
116        path.join(resources, 'uber'),
117    )
118    if filename.startswith(dirs):
119      return self.output_api.PresubmitError(error_text)
120    else:
121      return self.output_api.PresubmitPromptWarning(error_text)
122
123  def RunChecks(self):
124    """Check for violations of the Chromium JavaScript style guide. See
125       http://chromium.org/developers/web-development-style-guide#TOC-JavaScript
126    """
127
128    import sys
129    import warnings
130    old_path = sys.path
131    old_filters = warnings.filters
132
133    try:
134      closure_linter_path = self.input_api.os_path.join(
135          self.input_api.change.RepositoryRoot(),
136          "third_party",
137          "closure_linter")
138      gflags_path = self.input_api.os_path.join(
139          self.input_api.change.RepositoryRoot(),
140          "third_party",
141          "python_gflags")
142
143      sys.path.insert(0, closure_linter_path)
144      sys.path.insert(0, gflags_path)
145
146      warnings.filterwarnings('ignore', category=DeprecationWarning)
147
148      from closure_linter import checker, errors
149      from closure_linter.common import errorhandler
150
151    finally:
152      sys.path = old_path
153      warnings.filters = old_filters
154
155    class ErrorHandlerImpl(errorhandler.ErrorHandler):
156      """Filters out errors that don't apply to Chromium JavaScript code."""
157
158      def __init__(self, re):
159        self._errors = []
160        self.re = re
161
162      def HandleFile(self, filename, first_token):
163        self._filename = filename
164
165      def HandleError(self, error):
166        if (self._valid(error)):
167          error.filename = self._filename
168          self._errors.append(error)
169
170      def GetErrors(self):
171        return self._errors
172
173      def HasErrors(self):
174        return bool(self._errors)
175
176      def _valid(self, error):
177        """Check whether an error is valid. Most errors are valid, with a few
178           exceptions which are listed here.
179        """
180
181        is_grit_statement = bool(
182            self.re.search("</?(include|if)", error.token.line))
183
184        # Ignore missing spaces before "(" until Promise#catch issue is solved.
185        # http://crbug.com/338301
186        if (error.code == errors.MISSING_SPACE and error.token.string == '(' and
187           'catch(' in error.token.line):
188          return False
189
190        return not is_grit_statement and error.code not in [
191            errors.COMMA_AT_END_OF_LITERAL,
192            errors.JSDOC_ILLEGAL_QUESTION_WITH_PIPE,
193            errors.JSDOC_TAG_DESCRIPTION_ENDS_WITH_INVALID_CHARACTER,
194            errors.LINE_TOO_LONG,
195            errors.MISSING_JSDOC_TAG_THIS,
196        ]
197
198    results = []
199
200    affected_files = self.input_api.change.AffectedFiles(
201        file_filter=self.file_filter,
202        include_deletes=False)
203    affected_js_files = filter(lambda f: f.LocalPath().endswith('.js'),
204                               affected_files)
205    for f in affected_js_files:
206      error_lines = []
207
208      # Check for the following:
209      # * document.getElementById()
210      # * the 'const' keyword
211      # * Passing an empty array to 'chrome.send()'
212      for i, line in enumerate(f.NewContents(), start=1):
213        error_lines += filter(None, [
214            self.ChromeSendCheck(i, line),
215            self.ConstCheck(i, line),
216            self.GetElementByIdCheck(i, line),
217            self.InheritDocCheck(i, line),
218            self.WrapperTypeCheck(i, line),
219            self.VarNameCheck(i, line),
220        ])
221
222      # Use closure_linter to check for several different errors
223      error_handler = ErrorHandlerImpl(self.input_api.re)
224      js_checker = checker.JavaScriptStyleChecker(error_handler)
225      js_checker.Check(self.input_api.os_path.join(
226          self.input_api.change.RepositoryRoot(),
227          f.LocalPath()))
228
229      for error in error_handler.GetErrors():
230        highlight = self.error_highlight(
231            error.token.start_index, error.token.length)
232        error_msg = '  line %d: E%04d: %s\n%s\n%s' % (
233            error.token.line_number,
234            error.code,
235            error.message,
236            error.token.line.rstrip(),
237            highlight)
238        error_lines.append(error_msg)
239
240      if error_lines:
241        error_lines = [
242            'Found JavaScript style violations in %s:' %
243            f.LocalPath()] + error_lines
244        results.append(self._makeErrorOrWarning(
245            '\n'.join(error_lines), f.AbsoluteLocalPath()))
246
247    if results:
248      results.append(self.output_api.PresubmitNotifyResult(
249          'See the JavaScript style guide at '
250          'http://www.chromium.org/developers/web-development-style-guide'
251          '#TOC-JavaScript and if you have any feedback about the JavaScript '
252          'PRESUBMIT check, contact tbreisacher@chromium.org or '
253          'dbeam@chromium.org'))
254
255    return results
256