Add support for checking missing parameters in Numpy docstrings

Fixes PyCQA#394

This adds support for checking missing arguments in Numpy docstrings.

Author: sambhav

src/pydocstyle/checker.py

@@ -676,7 +676,7 @@ def _check_numpy_section(cls, docstring, definition, context):
         if suffix:
             yield violations.D406(capitalized_section, context.line.strip())
 
-        if capitalized_section in ("Parameters"):
+        if capitalized_section == "Parameters":
             yield from cls._check_parameters_section(docstring, definition, context)
 
     @staticmethod
@@ -712,7 +712,7 @@ def _check_parameters_section(docstring, definition, context):
                 # on the current line.
                 else:
                     parameters = current_line.strip()
-                # Numpy allow grouping of multiple parameters of same
+                # Numpy allows grouping of multiple parameters of same
                 # type in the same line. They are comma separated.
                 parameter_list = parameters.split(",")
                 for parameter in parameter_list:
@@ -734,6 +734,19 @@ def _check_args_section(docstring, definition, context):
             match = ConventionChecker.GOOGLE_ARGS_REGEX.match(line)
             if match:
                 docstring_args.add(match.group(1))
+        yield from ConventionChecker._check_missing_args(docstring_args, definition)
+
+
+    @staticmethod
+    def _check_missing_args(docstring_args, definition):
+        """D417: Yield error for missing arguments in docstring.
+
+        Given a list of arguments found in the docstring and the
+        callable definition, it checks if all the arguments of the
+        callable are present in the docstring, else it yields a
+        D417 with a list of missing arguments.
+
+        """
         function_args = get_function_args(definition.source)
         # If the method isn't static, then we skip the first
         # positional argument as it is `cls` or `self`

src/tests/test_cases/sections.py

@@ -277,8 +277,8 @@ def missing_colon_google_style_section():  # noqa: D406, D407
 @expect(_D213)
 @expect("D417: Missing arguments in the docstring "
         "(argument(s) 'y' missing in "
-        "'test_missing_args' docstring)")
-def test_missing_args(x=1, y=2):  # noqa: D406, D407
+        "'test_missing_google_args' docstring)")
+def test_missing_google_args(x=1, y=2):  # noqa: D406, D407
     """Toggle the gizmo.
 
     Args:
@@ -287,7 +287,7 @@ def test_missing_args(x=1, y=2):  # noqa: D406, D407
     """
 
 
-class Test:  # noqa: D203
+class TestGoogle:  # noqa: D203
     """Test class."""
 
     def test_method(self, test, another_test):  # noqa: D213, D407
@@ -333,3 +333,78 @@ def test_missing_args_static_method(a, x, y, z=3):  # noqa: D213, D407
             x: Another parameter.
 
         """
+
+
+@expect(_D213)
+@expect("D417: Missing arguments in the docstring "
+        "(argument(s) 'y' missing in "
+        "'test_missing_numpy_args' docstring)")
+def test_missing_numpy_args(x=1, y=2):  # noqa: D406, D407
+    """Toggle the gizmo.
+
+    Parameters
+    ----------
+    x : int
+        The greatest integer.
+
+    """
+
+
+class TestNumpy:  # noqa: D203
+    """Test class."""
+
+    def test_method(self, test, another_test, x=1, y=2):  # noqa: D213, D407
+        """Test a valid args section.
+
+        Parameters
+        ----------
+        test, another_test
+            Some parameters without type.
+        x, y : int
+            Some integer parameters.
+
+        """
+
+    @expect("D417: Missing arguments in the docstring "
+            "(argument(s) 'test, y, z' missing in "
+            "'test_missing_args' docstring)", arg_count=4)
+    def test_missing_args(self, test, x, y, z=3, t=1):  # noqa: D213, D407
+        """Test a valid args section.
+
+        Parameters
+        ----------
+        x, t : int
+            Some parameters.
+
+
+        """
+
+    @classmethod
+    @expect("D417: Missing arguments in the docstring "
+            "(argument(s) 'test, y, z' missing in "
+            "'test_missing_args_class_method' docstring)", arg_count=4)
+    def test_missing_args_class_method(cls, test, x, y, z=3):  # noqa: D213, D407
+        """Test a valid args section.
+
+        Parameters
+        ----------
+        x
+            Another parameter.
+
+        """
+
+    @staticmethod
+    @expect("D417: Missing arguments in the docstring "
+            "(argument(s) 'a, z' missing in "
+            "'test_missing_args_static_method' docstring)", arg_count=3)
+    def test_missing_args_static_method(a, x, y, z=3, t=1):  # noqa: D213, D407
+        """Test a valid args section.
+
+        Parameters
+        ----------
+        x, y
+            Another parameter.
+        t : int
+            Yet another parameter.
+
+        """