Tolerate no Sphinx parameter documentation at all: unit test

3 files changed, 418 insertions, 0 deletions

diff --git a/pylint/extensions/__init__.py b/pylint/extensions/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/pylint/extensions/__init__.py
diff --git a/pylint/extensions/check_docs.py b/pylint/extensions/check_docs.py
new file mode 100644
index 0000000..2319ac2
--- /dev/null
+++ b/pylint/extensions/check_docs.py
@@ -0,0 +1,206 @@
+"""Pylint plugin for Sphinx parameter documentation checking
+"""
+from __future__ import print_function, division, absolute_import
+
+import re
+
+from pylint.interfaces import IAstroidChecker
+from pylint.checkers import BaseChecker
+import astroid.scoped_nodes
+
+
+class SphinxDocChecker(BaseChecker):
+    """Checker for Sphinx documentation parameters
+
+    * Check that all function, method and constructor parameters are mentioned
+      in the Sphinx params and types part of the docstring. By convention,
+      constructor parameters are documented in the class docstring.
+    * Check that there are no naming inconsistencies between the signature and
+      the documentation, i.e. also report documented parameters that are missing
+      in the signature. This is important to find cases where parameters are
+      renamed only in the code, not in the documentation.
+
+    Activate this checker by adding the line::
+
+        load-plugins=pylint.extensions.check_docs
+
+    to the ``MASTER`` section of your ``.pylintrc``.
+
+    :param linter: linter object
+    :type linter: :class:`pylint.lint.PyLinter`
+    """
+    __implements__ = IAstroidChecker
+
+    name = 'Sphinx doc checks'
+    msgs = {
+        'W9003': ('"%s" missing or differing in Sphinx params',
+                  'missing-sphinx-param',
+                  'Please add Sphinx param declarations for all arguments.'),
+        'W9004': ('"%s" missing or differing in Sphinx types',
+                  'missing-sphinx-type',
+                  'Please add Sphinx type declarations for all arguments.'),
+    }
+
+    options = ()
+
+    priority = -2
+
+    def __init__(self, linter=None):
+        BaseChecker.__init__(self, linter)
+
+    def visit_function(self, node):
+        """Called for function and method definitions (def).
+
+        :param node: Node for a function or method definition in the AST
+        :type node: :class:`astroid.scoped_nodes.Function`
+        """
+        self.check_arguments_in_docstring(node, node.doc, node.args)
+
+    re_for_parameters_see = re.compile(r"""
+        For\s+the\s+(other)?\s*parameters\s*,\s+see
+        """, re.X | re.S)
+
+    re_prefix_of_func_name = re.compile(r"""
+        .*                      # part before final dot
+        \.                      # final dot
+        """, re.X | re.S)
+
+    re_sphinx_param_in_docstring = re.compile(r"""
+        :param                  # Sphinx keyword
+        \s+                     # whitespace
+
+        (?:                     # optional type declaration
+        (\w+)
+        \s+
+        )?
+
+        (\w+)                   # Parameter name
+        \s*                     # whitespace
+        :                       # final colon
+        """, re.X | re.S)
+
+    re_sphinx_type_in_docstring = re.compile(r"""
+        :type                   # Sphinx keyword
+        \s+                     # whitespace
+        (\w+)                   # Parameter name
+        \s*                     # whitespace
+        :                       # final colon
+        """, re.X | re.S)
+
+    not_needed_param_in_docstring = set(['self', 'cls'])
+
+    def check_arguments_in_docstring(self, node, doc, arguments_node):
+        """Check that all arguments in a function, method or class constructor
+        on the one hand and the arguments mentioned in the Sphinx tags 'param'
+        and 'type' on the other hand are consistent with each other.
+
+        * Undocumented parameters except 'self' are noticed.
+        * Undocumented parameter types except for 'self' and the ``*<args>``
+          and ``**<kwargs>`` parameters are noticed.
+        * Parameters mentioned in the Sphinx documentation that don't or no
+          longer exist in the function parameter list are noticed.
+        * If there is a Sphinx link like ``:meth:...`` or ``:func:...`` to a
+          function carrying the same name as the current function, missing
+          parameter documentations are tolerated, but the existing parameters
+          mentioned in the documentation are checked.
+
+        :param node: Node for a function, method or class definition in the AST.
+        :type node: :class:`astroid.scoped_nodes.Function` or
+            :class:`astroid.scoped_nodes.Class`
+
+        :param doc: Docstring for the function, method or class.
+        :type doc: str
+
+        :param arguments_node: Arguments node for the function, method or
+            class constructor.
+        :type arguments_node: :class:`astroid.scoped_nodes.Arguments`
+        """
+        # Tolerate missing param or type declarations if there is a link to
+        # another method carrying the same name.
+        if node.doc is None:
+            return
+
+        tolerate_missing_params = False
+        if self.re_for_parameters_see.search(doc) is not None:
+            tolerate_missing_params = True
+
+        # Collect the function arguments.
+        expected_argument_names = [arg.name for arg in arguments_node.args]
+        not_needed_type_in_docstring = (
+            self.not_needed_param_in_docstring.copy())
+
+        if arguments_node.vararg is not None:
+            expected_argument_names.append(arguments_node.vararg)
+            not_needed_type_in_docstring.add(arguments_node.vararg)
+        if arguments_node.kwarg is not None:
+            expected_argument_names.append(arguments_node.kwarg)
+            not_needed_type_in_docstring.add(arguments_node.kwarg)
+
+        def compare_args(found_argument_names, message_id, not_needed_names):
+            """Compare the found argument names with the expected ones and
+            generate a message if there are inconsistencies.
+
+            :param list found_argument_names: argument names found in the
+                docstring
+
+            :param str message_id: pylint message id
+
+            :param not_needed_names: names that may be omitted
+            :type not_needed_names: set of str
+            """
+            if not tolerate_missing_params:
+                missing_or_differing_argument_names = (
+                    (set(expected_argument_names) ^ set(found_argument_names))
+                    - not_needed_names)
+            else:
+                missing_or_differing_argument_names = (
+                    (set(found_argument_names) - set(expected_argument_names))
+                    - not_needed_names)
+
+            if missing_or_differing_argument_names:
+                self.add_message(
+                    message_id,
+                    args=(', '.join(
+                        sorted(missing_or_differing_argument_names)),),
+                    node=node)
+
+        # Sphinx param declarations
+        found_argument_names = []
+        for match in re.finditer(self.re_sphinx_param_in_docstring, doc):
+            name = match.group(2)
+            found_argument_names.append(name)
+            if match.group(1) is not None:
+                not_needed_type_in_docstring.add(name)
+        compare_args(found_argument_names, 'missing-sphinx-param',
+                     self.not_needed_param_in_docstring)
+
+        # Sphinx type declarations
+        found_argument_names = re.findall(self.re_sphinx_type_in_docstring, doc)
+        compare_args(found_argument_names, 'missing-sphinx-type',
+                     not_needed_type_in_docstring)
+
+    constructor_names = set(["__init__", "__new__"])
+
+    def visit_class(self, node):
+        """Called for class definitions.
+
+        :param node: Node for a class definition in the AST
+        :type node: :class:`astroid.scoped_nodes.Class`
+        """
+        for body_item in node.body:
+            if (isinstance(body_item, astroid.scoped_nodes.Function)
+                    and hasattr(body_item, 'name')):
+                if body_item.name in self.constructor_names:
+                    self.check_arguments_in_docstring(
+                        node, node.doc, body_item.args)
+                else:
+                    self.visit_function(body_item)
+
+
+def register(linter):
+    """Required method to auto register this checker.
+
+    :param linter: Main interface object for Pylint plugins
+    :type linter: Pylint object
+    """
+    linter.register_checker(SphinxDocChecker(linter))
diff --git a/pylint/extensions/test/test_check_docs.py b/pylint/extensions/test/test_check_docs.py
new file mode 100644
index 0000000..5c4710c
--- /dev/null
+++ b/pylint/extensions/test/test_check_docs.py
@@ -0,0 +1,212 @@
+"""Unit tests for the pylint checkers in :mod:`pylint.extensions.check_docs`,
+in particular the Sphinx parameter documentation checker `SphinxDocChecker`
+"""
+from __future__ import division, print_function, absolute_import
+
+import unittest
+
+from astroid import test_utils
+from pylint.testutils import CheckerTestCase, Message
+
+from pylint.extensions.check_docs import SphinxDocChecker
+
+
+class SpinxDocCheckerTest(CheckerTestCase):
+    """Tests for pylint_plugin.SphinxDocChecker"""
+    CHECKER_CLASS = SphinxDocChecker
+
+    def test_missing_func_params_in_docstring(self):
+        """Example of a function with missing parameter documentation in the
+        docstring
+        """
+        node = test_utils.extract_node("""
+        def function_foo(x, y):
+            '''docstring ...
+
+            :param x: bla
+            
+            missing parameter documentation'''
+            pass
+        """)
+        with self.assertAddsMessages(
+            Message(
+                msg_id='missing-sphinx-param',
+                node=node,
+                args=('y',)),
+            Message(
+                msg_id='missing-sphinx-type',
+                node=node,
+                args=('x, y',))
+        ):
+            self.checker.visit_function(node)
+
+    def test_tolerate_no_sphinx_param_documentation_at_all(self):
+        """Example of a function with no Sphinx parameter documentation at all
+        """
+        node = test_utils.extract_node("""
+        def function_foo(x, y):
+            '''docstring ...
+
+            missing parameter documentation'''
+            pass
+        """)
+        with self.assertNoMessages():
+            self.checker.visit_function(node)
+
+    def test_missing_method_params_in_docstring(self):
+        """Example of a class method with missing parameter documentation in
+        the docstring
+        """
+        node = test_utils.extract_node("""
+        class Foo(object):
+            def method_foo(self, x, y):
+                '''docstring ...
+
+                missing parameter documentation
+
+                :param x: bla
+                '''
+                pass
+        """)
+        method_node = node.body[0]
+        with self.assertAddsMessages(
+            Message(
+                msg_id='missing-sphinx-param',
+                node=method_node,
+                args=('y',)),
+            Message(
+                msg_id='missing-sphinx-type',
+                node=method_node,
+                args=('x, y',))
+        ):
+            self.checker.visit_class(node)
+
+    def test_existing_func_params_in_docstring(self):
+        """Example of a function with correctly documented parameters and
+        return values
+        """
+        node = test_utils.extract_node("""
+        def function_foo(xarg, yarg, zarg):
+            '''function foo ...
+
+            :param xarg: bla xarg
+            :type xarg: int
+
+            :param yarg: bla yarg
+            :type yarg: float
+
+            :param int zarg: bla zarg
+
+            :return: sum
+            :rtype: float
+            '''
+            return xarg + yarg
+        """)
+        with self.assertNoMessages():
+            self.checker.visit_function(node)
+
+    def test_wrong_name_of_func_params_in_docstring(self):
+        """Example of functions with inconsistent parameter names in the
+        signature and in the documentation
+        """
+        node = test_utils.extract_node("""
+        def function_foo(xarg, yarg, zarg):
+            '''function foo ...
+
+            :param xarg1: bla xarg
+            :type xarg: int
+
+            :param yarg: bla yarg
+            :type yarg1: float
+
+            :param str zarg1: bla zarg
+            '''
+            return xarg + yarg
+        """)
+        with self.assertAddsMessages(
+            Message(
+                msg_id='missing-sphinx-param',
+                node=node,
+                args=('xarg, xarg1, zarg, zarg1',)),
+            Message(
+                msg_id='missing-sphinx-type',
+                node=node,
+                args=('yarg, yarg1, zarg',)),
+        ):
+            self.checker.visit_function(node)
+
+        node = test_utils.extract_node("""
+        def function_foo(xarg, yarg):
+            '''function foo ...
+
+            :param yarg1: bla yarg
+            :type yarg1: float
+
+            For the other parameters, see bla.
+            '''
+            return xarg + yarg
+        """)
+        with self.assertAddsMessages(
+            Message(
+                msg_id='missing-sphinx-param',
+                node=node,
+                args=('yarg1',)),
+            Message(
+                msg_id='missing-sphinx-type',
+                node=node,
+                args=('yarg1',))
+        ):
+            self.checker.visit_function(node)
+
+    def test_see_sentence_for_func_params_in_docstring(self):
+        """Example for the usage of "For the other parameters, see" to avoid
+        too many repetitions, e.g. in functions or methods adhering to a
+        given interface
+        """
+        node = test_utils.extract_node("""
+        def function_foo(xarg, yarg):
+            '''function foo ...
+
+            :param yarg: bla yarg
+            :type yarg: float
+
+            For the other parameters, see :func:`bla`
+            '''
+            return xarg + yarg
+        """)
+        with self.assertNoMessages():
+            self.checker.visit_function(node)
+
+    def test_constr_params_in_class(self):
+        """Example of a class with missing constructor parameter documentation
+
+        Everything is completely analogous to functions.
+        """
+        node = test_utils.extract_node("""
+        class ClassFoo(object):
+            '''docstring foo
+
+            :param y: bla
+            
+            missing constructor parameter documentation
+            '''
+
+            def __init__(self, x, y):
+                pass
+
+        """)
+        with self.assertAddsMessages(
+            Message(
+                msg_id='missing-sphinx-param',
+                node=node,
+                args=('x',)),
+            Message(
+                msg_id='missing-sphinx-type',
+                node=node,
+                args=('x, y',))
+        ):
+            self.checker.visit_class(node)
+
+
+if __name__ == '__main__':
+    unittest.main()