Add presubmit check and automatic update script for ExtensionPermission enum.

tools/extra_imports/strict_enum_value_checker.py

-# Copyright (c) 2012 The Chromium Authors. All rights reserved.
+# Copyright (c) 2014 The Chromium Authors. All rights reserved.

[rpaquay, 2014/02/18 21:39:26]

nit: remove the "(c"): see http://www.chromium.org/developers/coding-style
("file headers" section).

 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-"""Chromium presubmit script for src/chrome/browser/extensions.
+class StrictEnumValueChecker(object):
+  '''Verify that changes to enums are valid.
 
-See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
-for more details on the presubmit API built into gcl.
-"""
+  This class is used to check enums where reordering or deletion is not allowed,
+  and additions must be at the end of the enum, just prior to some "boundary"
+  entry. See comments at the top of the "extension_function_histogram_value.h"
+  file in chrome/browser/extensions for an example what are considered valid
+  changes. There are situations where this class gives false positive warnings,
+  i.e. it warns even though the edit is legitimate. Since the class warns using
+  prompt warnings, the user can always choose to continue. The main point is to
+  attract the attention to all (potentially or not) invalid edits.
 
-def GetPreferredTrySlaves():
-  return ['linux_chromeos']
-
-class HistogramValueChecker(object):
-  """Verify that changes to "extension_function_histogram_value.h" are valid.
-
-  See comments at the top of the "extension_function_histogram_value.h" file
-  for what are considered valid changes. There are situations where this script
-  gives false positive warnings, i.e. it warns even though the edit is
-  legitimate. Since the script warns using prompt warnings, the user can always
-  choose to continue. The main point is to attract the attention to all
-  (potentially or not) invalid edits.
-
-  """
-
-  # The name of the file we want to check against
-  LOCAL_PATH = "chrome/browser/extensions/extension_function_histogram_value.h"
-
-  # The markers we look for in the above source file as delimiters of the enum
-  # definition.
-  ENUM_START_MARKER = "enum HistogramValue {"
-  ENUM_END_MARKER = "  ENUM_BOUNDARY"
-
-  def __init__(self, input_api, output_api):
+  '''
+  def __init__(self, input_api, output_api, start_marker, end_marker, path):
     self.input_api = input_api
     self.output_api = output_api
+    self.start_marker = start_marker
+    self.end_marker = end_marker
+    self.path = path
     self.results = []
 
   class EnumRange(object):
-    """Represents a range of line numbers (1-based)"""
+    '''Represents a range of line numbers (1-based)'''

[rpaquay, 2014/02/18 21:39:26]

nit: is there a particular reason you use single quotes in this file? (it makes
the diff more difficult to read).

[ahernandez, 2014/02/20 17:23:42]

There really wasn't a reason other than a personal preference. I can easily
change it back to using double quotes.

     def __init__(self, first_line, last_line):
       self.first_line = first_line
       self.last_line = last_line
 
     def Count(self):
       return self.last_line - self.first_line + 1
 
     def Contains(self, line_num):
       return self.first_line <= line_num and line_num <= self.last_line
 
   def LogInfo(self, message):
     self.input_api.logging.info(message)
     return
 
   def LogDebug(self, message):
     self.input_api.logging.debug(message)
     return
 
   def ComputeEnumRangeInContents(self, contents):
-    """Returns an |EnumRange| object representing the line extent of the
+    '''Returns an |EnumRange| object representing the line extent of the
     HistogramValue enum members in |contents|. The line numbers are 1-based,
     compatible with line numbers returned by AffectedFile.ChangeContents().
     |contents| is a list of strings reprenting the lines of a text file.
 
-    If either ENUM_START_MARKER or ENUM_END_MARKER cannot be found in
+    If either start_marker or end_marker cannot be found in
     |contents|, returns None and emits detailed warnings about the problem.
 
-    """
+    '''
     first_enum_line = 0
     last_enum_line = 0
     line_num = 1  # Line numbers are 1-based
     for line in contents:
-      if line.startswith(self.ENUM_START_MARKER):
+      if line.startswith(self.start_marker):
         first_enum_line = line_num + 1
-      elif line.startswith(self.ENUM_END_MARKER):
+      elif line.startswith(self.end_marker):
         last_enum_line = line_num
       line_num += 1
 
     if first_enum_line == 0:
-      self.EmitWarning("The presubmit script could not find the start of the "
-                       "enum definition (\"%s\"). Did the enum definition "
-                       "change?" % self.ENUM_START_MARKER)
+      self.EmitWarning('The presubmit script could not find the start of the '
+                       'enum definition ("%s"). Did the enum definition '
+                       'change?' % self.start_marker)
       return None
 
     if last_enum_line == 0:
-      self.EmitWarning("The presubmit script could not find the end of the "
-                       "enum definition (\"%s\"). Did the enum definition "
-                       "change?" % self.ENUM_END_MARKER)
+      self.EmitWarning('The presubmit script could not find the end of the '
+                       'enum definition ("%s"). Did the enum definition '
+                       'change?' % self.end_marker)
       return None
 
     if first_enum_line >= last_enum_line:
-      self.EmitWarning("The presubmit script located the start of the enum "
-                       "definition (\"%s\" at line %d) *after* its end "
-                       "(\"%s\" at line %d). Something is not quite right."
-                       % (self.ENUM_START_MARKER, first_enum_line,
-                          self.ENUM_END_MARKER, last_enum_line))
+      self.EmitWarning('The presubmit script located the start of the enum '
+                       'definition ("%s" at line %d) *after* its end '
+                       '("%s" at line %d). Something is not quite right.'
+                       % (self.start_marker, first_enum_line,
+                          self.end_marker, last_enum_line))
       return None
 
-    self.LogInfo("Line extent of |HistogramValue| enum definition: "
-                 "first_line=%d, last_line=%d."
+    self.LogInfo('Line extent of |HistogramValue| enum definition: '
+                 'first_line=%d, last_line=%d.'
                  % (first_enum_line, last_enum_line))
     return self.EnumRange(first_enum_line, last_enum_line)
 
   def ComputeEnumRangeInNewFile(self, affected_file):
     return self.ComputeEnumRangeInContents(affected_file.NewContents())
 
-  def GetLongMessage(self):
-    return str("The file \"%s\" contains the definition of the "
-               "|HistogramValue| enum which should be edited in specific ways "

[rpaquay, 2014/02/18 21:39:26]

"HistogramValue" is too specific in this file, as this is the factored out code.

-               "only - *** read the comments at the top of the header file ***"
-               ". There are changes to the file that may be incorrect and "
-               "warrant manual confirmation after review. Note that this "
-               "presubmit script can not reliably report the nature of all "
-               "types of invalid changes, especially when the diffs are "
-               "complex. For example, an invalid deletion may be reported "
-               "whereas the change contains a valid rename."
-               % self.LOCAL_PATH)
+  def GetLongMessage(self, local_path):
+    return str('The file "%s" contains the definition of the '
+               '|HistogramValue| enum which should be edited in specific ways '
+               'only - *** read the comments at the top of the header file ***'
+               '. There are changes to the file that may be incorrect and '
+               'warrant manual confirmation after review. Note that this '
+               'presubmit script can not reliably report the nature of all '
+               'types of invalid changes, especially when the diffs are '
+               'complex. For example, an invalid deletion may be reported '
+               'whereas the change contains a valid rename.'
+               % local_path)
 
   def EmitWarning(self, message, line_number=None, line_text=None):
-    """Emits a presubmit prompt warning containing the short message
+    '''Emits a presubmit prompt warning containing the short message
     |message|. |item| is |LOCAL_PATH| with optional |line_number| and
     |line_text|.
 
-    """
+    '''
     if line_number is not None and line_text is not None:
-      item = "%s(%d): %s" % (self.LOCAL_PATH, line_number, line_text)
+      item = '%s(%d): %s' % (self.path, line_number, line_text)
     elif line_number is not None:
-      item = "%s(%d)" % (self.LOCAL_PATH, line_number)
+      item = '%s(%d)' % (self.path, line_number)
     else:
-      item = self.LOCAL_PATH
-    long_message = self.GetLongMessage()
+      item = self.path
+    long_message = self.GetLongMessage(self.path)
     self.LogInfo(message)
     self.results.append(
       self.output_api.PresubmitPromptWarning(message, [item], long_message))
 
   def CollectRangesInsideEnumDefinition(self, affected_file,
                                         first_line, last_line):
-    """Returns a list of triplet (line_start, line_end, line_text) of ranges of
+    '''Returns a list of triplet (line_start, line_end, line_text) of ranges of
     edits changes. The |line_text| part is the text at line |line_start|.
     Since it used only for reporting purposes, we do not need all the text
     lines in the range.
 
-    """
+    '''
     results = []
     previous_line_number = 0
     previous_range_start_line_number = 0
-    previous_range_start_text = ""
+    previous_range_start_text = ''
 
     def addRange():
       tuple = (previous_range_start_line_number,
                previous_line_number,
                previous_range_start_text)
       results.append(tuple)
 
     for line_number, line_text in affected_file.ChangedContents():
       if first_line <= line_number and line_number <= last_line:
-        self.LogDebug("Line change at line number " + str(line_number) + ": " +
+        self.LogDebug('Line change at line number ' + str(line_number) + ': ' +
                       line_text)
         # Start a new interval if none started
         if previous_range_start_line_number == 0:
           previous_range_start_line_number = line_number
           previous_range_start_text = line_text
         # Add new interval if we reached past the previous one
         elif line_number != previous_line_number + 1:
           addRange()
           previous_range_start_line_number = line_number
           previous_range_start_text = line_text
         previous_line_number = line_number
 
     # Add a last interval if needed
     if previous_range_start_line_number != 0:
         addRange()
     return results
 
   def CheckForFileDeletion(self, affected_file):
-    """Emits a warning notification if file has been deleted """
+    '''Emits a warning notification if file has been deleted '''
     if not affected_file.NewContents():
-      self.EmitWarning("The file seems to be deleted in the changelist. If "
-                       "your intent is to really delete the file, the code in "
-                       "PRESUBMIT.py should be updated to remove the "
-                       "|HistogramValueChecker| class.");

[rpaquay, 2014/02/18 21:39:26]

nit: HistogramValueChecker is too specific.

+      self.EmitWarning('The file seems to be deleted in the changelist. If '
+                       'your intent is to really delete the file, the code in '
+                       'PRESUBMIT.py should be updated to remove the '
+                       '|HistogramValueChecker| class.');
       return False
     return True
 
   def GetDeletedLinesFromScmDiff(self, affected_file):
-    """Return a list of of line numbers (1-based) corresponding to lines
+    '''Return a list of of line numbers (1-based) corresponding to lines
     deleted from the new source file (if they had been present in it). Note
     that if multiple contiguous lines have been deleted, the returned list will
     contain contiguous line number entries. To prevent false positives, we
     return deleted line numbers *only* from diff chunks which decrease the size
     of the new file.
 
     Note: We need this method because we have access to neither the old file
     content nor the list of "delete" changes from the current presubmit script
     API.
 
-    """
+    '''
     results = []
     line_num = 0
     deleting_lines = False
     for line in affected_file.GenerateScmDiff().splitlines():
       # Parse the unified diff chunk optional section heading, which looks like
       # @@ -l,s +l,s @@ optional section heading
       m = self.input_api.re.match(
         r'^@@ \-([0-9]+)\,([0-9]+) \+([0-9]+)\,([0-9]+) @@', line)
       if m:
         old_line_num = int(m.group(1))
         old_size = int(m.group(2))
         new_line_num = int(m.group(3))
         new_size = int(m.group(4))
         line_num = new_line_num
         # Return line numbers only from diff chunks decreasing the size of the
         # new file
         deleting_lines = old_size > new_size
         continue
       if not line.startswith('-'):
         line_num += 1
       if deleting_lines and line.startswith('-') and not line.startswith('--'):
         results.append(line_num)
     return results
 
   def CheckForEnumEntryDeletions(self, affected_file):
-    """Look for deletions inside the enum definition. We currently use a
+    '''Look for deletions inside the enum definition. We currently use a
     simple heuristics (not 100% accurate): if there are deleted lines inside
     the enum definition, this might be a deletion.
 
-    """
+    '''
     range_new = self.ComputeEnumRangeInNewFile(affected_file)
     if not range_new:
       return False
 
     is_ok = True
     for line_num in self.GetDeletedLinesFromScmDiff(affected_file):
       if range_new.Contains(line_num):
-        self.EmitWarning("It looks like you are deleting line(s) from the "
-                         "enum definition. This should never happen.",
+        self.EmitWarning('It looks like you are deleting line(s) from the '
+                         'enum definition. This should never happen.',
                          line_num)
         is_ok = False
     return is_ok
 
   def CheckForEnumEntryInsertions(self, affected_file):
     range = self.ComputeEnumRangeInNewFile(affected_file)
     if not range:
       return False
 
     first_line = range.first_line
     last_line = range.last_line
 
     # Collect the range of changes inside the enum definition range.
     is_ok = True
     for line_start, line_end, line_text in \
           self.CollectRangesInsideEnumDefinition(affected_file,
                                                  first_line,
                                                  last_line):
       # The only edit we consider valid is adding 1 or more entries *exactly*
       # at the end of the enum definition. Every other edit inside the enum
       # definition will result in a "warning confirmation" message.
       #
       # TODO(rpaquay): We currently cannot detect "renames" of existing entries
       # vs invalid insertions, so we sometimes will warn for valid edits.
       is_valid_edit = (line_end == last_line - 1)
 
-      self.LogDebug("Edit range in new file at starting at line number %d and "
-                    "ending at line number %d: valid=%s"
+      self.LogDebug('Edit range in new file at starting at line number %d and '
+                    'ending at line number %d: valid=%s'
                     % (line_start, line_end, is_valid_edit))
 
       if not is_valid_edit:
-        self.EmitWarning("The change starting at line %d and ending at line "
-                         "%d is *not* located *exactly* at the end of the "
-                         "enum definition. Unless you are renaming an "
-                         "existing entry, this is not a valid changes, as new "
-                         "entries should *always* be added at the end of the "
-                         "enum definition, right before the 'ENUM_BOUNDARY' "
-                         "entry." % (line_start, line_end),
+        self.EmitWarning('The change starting at line %d and ending at line '
+                         '%d is *not* located *exactly* at the end of the '
+                         'enum definition. Unless you are renaming an '
+                         'existing entry, this is not a valid changes, as new '
+                         'entries should *always* be added at the end of the '
+                         'enum definition, right before the "ENUM_BOUNDARY" '
+                         'entry.' % (line_start, line_end),
                          line_start,
                          line_text)
         is_ok = False
     return is_ok
 
   def PerformChecks(self, affected_file):
     if not self.CheckForFileDeletion(affected_file):
       return
     if not self.CheckForEnumEntryDeletions(affected_file):
       return
     if not self.CheckForEnumEntryInsertions(affected_file):
       return
 
   def ProcessHistogramValueFile(self, affected_file):
-    self.LogInfo("Start processing file \"%s\"" % affected_file.LocalPath())
+    self.LogInfo('Start processing file "%s"' % affected_file.LocalPath())
     self.PerformChecks(affected_file)
-    self.LogInfo("Done processing file \"%s\"" % affected_file.LocalPath())
+    self.LogInfo('Done processing file "%s"' % affected_file.LocalPath())
 
   def Run(self):
     for file in self.input_api.AffectedFiles(include_deletes=True):
-      if file.LocalPath() == self.LOCAL_PATH:
+      if file.LocalPath() == self.path:
         self.ProcessHistogramValueFile(file)
     return self.results
-
-def CheckChangeOnUpload(input_api, output_api):
-  results = []
-  results += HistogramValueChecker(input_api, output_api).Run()
-  results += input_api.canned_checks.CheckPatchFormatted(input_api, output_api)
-  return results
-