Allow no type in Numpy param docstrings for ``mising-param-doc`` (#5231)

This closes #5222

See https://numpydoc.readthedocs.io/en/latest/format.html#parameters for reference

4 files changed, 53 insertions, 6 deletions

diff --git a/ChangeLog b/ChangeLog
index 90810665f..8b1e97508 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -103,6 +103,11 @@ Release date: TBA
 
   Closes #3733
 
+* ``mising-param-doc`` now correctly handles Numpy parameter documentation without
+  explicit typing
+
+  Closes #5222
+
 * Update ``literal-comparison``` checker to ignore tuple literals
 
   Closes #3031
diff --git a/doc/whatsnew/2.12.rst b/doc/whatsnew/2.12.rst
index 0f16e4bdd..627a5eb07 100644
--- a/doc/whatsnew/2.12.rst
+++ b/doc/whatsnew/2.12.rst
@@ -123,3 +123,8 @@ Other Changes
   keyword parameters
 
   Closes #3733
+
+* ``mising-param-doc`` now correctly handles Numpy parameter documentation without
+  explicit typing
+
+  Closes #5222
diff --git a/pylint/extensions/_check_docs_utils.py b/pylint/extensions/_check_docs_utils.py
index 52f9e470c..92f91847c 100644
--- a/pylint/extensions/_check_docs_utils.py
+++ b/pylint/extensions/_check_docs_utils.py
@@ -23,7 +23,7 @@
 """Utility methods for docstring checking."""
 
 import re
-from typing import List
+from typing import List, Set, Tuple
 
 import astroid
 from astroid import nodes
@@ -731,9 +731,8 @@ class NumpyDocstring(GoogleDocstring):
 
     re_param_line = re.compile(
         fr"""
-        \s*  (\*{{0,2}}\w+)                                                 # identifier with potential asterisks
-        \s*  :
-        \s*  (?:({GoogleDocstring.re_multiple_type})(?:,\s+optional)?)?     # optional type declaration
+        \s*  (\*{{0,2}}\w+)(\s?(:|\n))                                      # identifier with potential asterisks
+        \s*  (?:({GoogleDocstring.re_multiple_type})(?:,\s+optional)?\n)?   # optional type declaration
         \s* (.*)                                                            # optional description
     """,
         re.X | re.S,
@@ -772,6 +771,38 @@ class NumpyDocstring(GoogleDocstring):
 
     supports_yields = True
 
+    def match_param_docs(self) -> Tuple[Set[str], Set[str]]:
+        """Matches parameter documentation section to parameter documentation rules"""
+        params_with_doc = set()
+        params_with_type = set()
+
+        entries = self._parse_section(self.re_param_section)
+        print(entries)
+        entries.extend(self._parse_section(self.re_keyword_param_section))
+        for entry in entries:
+            match = self.re_param_line.match(entry)
+            if not match:
+                continue
+
+            # check if parameter has description only
+            re_only_desc = re.match(r"\s*  (\*{0,2}\w+)\s*:?\n", entry)
+            if re_only_desc:
+                param_name = match.group(1)
+                param_desc = match.group(2)
+                param_type = None
+            else:
+                param_name = match.group(1)
+                param_type = match.group(3)
+                param_desc = match.group(4)
+
+            if param_type:
+                params_with_type.add(param_name)
+
+            if param_desc:
+                params_with_doc.add(param_name)
+
+        return params_with_doc, params_with_type
+
     @staticmethod
     def min_section_indent(section_match):
         return len(section_match.group(1))
diff --git a/tests/extensions/test_check_docs.py b/tests/extensions/test_check_docs.py
index 79836c21a..5fdbc0ee3 100644
--- a/tests/extensions/test_check_docs.py
+++ b/tests/extensions/test_check_docs.py
@@ -1338,13 +1338,17 @@ class TestParamDocChecker(CheckerTestCase):
     def test_finds_args_without_type_numpy(self) -> None:
         node = astroid.extract_node(
             '''
-        def my_func(named_arg, *args):
+        def my_func(named_arg, typed_arg: bool, untyped_arg, *args):
             """The docstring
 
             Args
             ----
             named_arg : object
                 Returned
+            typed_arg
+                Other argument without numpy type annotation
+            untyped_arg
+                Other argument without any type annotation
             *args :
                 Optional Arguments
 
@@ -1357,7 +1361,9 @@ class TestParamDocChecker(CheckerTestCase):
                 return named_arg
         '''
         )
-        with self.assertNoMessages():
+        with self.assertAddsMessages(
+            MessageTest(msg_id="missing-type-doc", node=node, args=("untyped_arg",))
+        ):
             self.checker.visit_functiondef(node)
 
     def test_finds_args_with_xref_type_google(self) -> None: