Added new error code (D403) for capitalization issues

Author: Nurdok

src/pep257.py

@@ -16,6 +16,7 @@
 import os
 import sys
 import copy
+import string
 import logging
 import tokenize as tk
 from itertools import takewhile, dropwhile, chain
@@ -454,9 +455,9 @@ def parse_definition(self, class_):
             docstring = self.parse_docstring()
             decorators = self._accumulated_decorators
             self._accumulated_decorators = []
-            log.debug("parsing nested defintions.")
+            log.debug("parsing nested definitions.")
             children = list(self.parse_definitions(class_))
-            log.debug("finished parsing nested defintions for '%s'", name)
+            log.debug("finished parsing nested definitions for '%s'", name)
             end = self.line - 1
         else:  # one-liner definition
             docstring = self.parse_docstring()
@@ -678,6 +679,11 @@ def to_rst(cls):
                          '%r, not %r')
 D402 = D4xx.create_error('D402', 'First line should not be the function\'s '
                                  '"signature"')
+D402 = D4xx.create_error('D402', 'First line should not be the function\'s '
+                                 '"signature"')
+D403 = D4xx.create_error('D403', 'First word of the first line should be '
+                                 'properly capitalized', '%r, not %r')
+
 
 
 class AttrDict(dict):
@@ -1592,6 +1598,18 @@ def check_no_signature(self, function, docstring):  # def context
             if function.name + '(' in first_line.replace(' ', ''):
                 return D402()
 
+    @check_for(Function)
+    def check_capitalized(self, function, docstring):
+        """D403: First word of the first line should be properly capitalized.
+
+        The [first line of a] docstring is a phrase ending in a period.
+
+        """
+        if docstring:
+            first_word = eval(docstring).split()[0]
+            if first_word != first_word.capitalize():
+                return D403(first_word.capitalize(), first_word)
+
     # Somewhat hard to determine if return value is mentioned.
     # @check(Function)
     def SKIP_check_return_type(self, function, docstring):

src/tests/test_cases/capitalization.py

@@ -0,0 +1,24 @@
+"""A valid module docstring."""
+
+from .expected import Expectation
+
+expectation = Expectation()
+expect = expectation.expect
+
+
+@expect("D403: First word of the first line should be properly capitalized "
+        "('Do', not 'do')")
+def not_capitalized():
+    """do something."""
+
+
+# Make sure empty docstrings don't generate capitalization errors.
+@expect("D103: Missing docstring in public function")
+def empty_docstring():
+    """"""
+
+
+@expect("D403: First word of the first line should be properly capitalized "
+        "('Get', not 'GET')")
+def all_caps():
+    """GET the request."""

src/tests/test_definitions.py

@@ -138,7 +138,7 @@ def test_token_stream():
 
 def test_pep257():
     """Run domain-specific tests from test.py file."""
-    test_cases = ('test', 'unicode_literals', 'nested_class')
+    test_cases = ('test', 'unicode_literals', 'nested_class', 'capitalization')
     for test_case in test_cases:
         case_module = __import__('test_cases.{0}'.format(test_case),
                                  globals=globals(),

src/tests/test_pep257.py

@@ -135,7 +135,7 @@ def function_with_bad_docstring(foo):
             return foo
     ''')
     expected_error_codes = set(('D100', 'D400', 'D401', 'D205', 'D209',
-                                'D210'))
+                                'D210', 'D403'))
     mock_open = mock.mock_open(read_data=function_to_check)
     from .. import pep257
     with mock.patch.object(pep257, 'tokenize_open', mock_open, create=True):