spellcheck will skip the rule names of mypy inline directives (#5929)

Co-authored-by: Eli Fine <eli.fine@resilience.com>
Co-authored-by: Daniël van Noord <13665637+DanielNoord@users.noreply.github.com>

4 files changed, 43 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index b903c1300..405d85f4e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1022,6 +1022,9 @@ Release date: 2022-03-24
 
   Closes #4955
 
+* Disable spellchecking of mypy rule names in ignore directives.
+  Closes #5929
+
 * Allow disabling ``duplicate-code`` with a disable comment when running through
   pylint.
 
diff --git a/doc/whatsnew/2.14.rst b/doc/whatsnew/2.14.rst
index f1704dd62..bf97f475d 100644
--- a/doc/whatsnew/2.14.rst
+++ b/doc/whatsnew/2.14.rst
@@ -145,6 +145,10 @@ Other Changes
 
   Closes #6372
 
+* Disable spellchecking of mypy rule names in ignore directives.
+
+  Closes #5929
+
 * ``implicit-str-concat`` will now be raised on calls like ``open("myfile.txt" "a+b")`` too.
 
   Closes #6441
diff --git a/pylint/checkers/spelling.py b/pylint/checkers/spelling.py
index c159f9172..cfa24da81 100644
--- a/pylint/checkers/spelling.py
+++ b/pylint/checkers/spelling.py
@@ -161,6 +161,7 @@ class ForwardSlashChunker(Chunker):
 
 
 CODE_FLANKED_IN_BACKTICK_REGEX = re.compile(r"(\s|^)(`{1,2})([^`]+)(\2)([^`]|$)")
+MYPY_IGNORE_DIRECTIVE_RULE_REGEX = re.compile(r"(\s|^)(type\: ignore\[[^\]]+\])(.*)")
 
 
 def _strip_code_flanked_in_backticks(line: str) -> str:
@@ -178,6 +179,21 @@ def _strip_code_flanked_in_backticks(line: str) -> str:
     )
 
 
+def _strip_mypy_ignore_directive_rule(line: str) -> str:
+    """Alter line so mypy rule name is ignored.
+
+    Pyenchant parses anything flanked by spaces as an individual token,
+    so this cannot be done at the individual filter level.
+    """
+
+    def replace_rule_name_but_leave_surrounding_characters(match_obj) -> str:
+        return match_obj.group(1) + match_obj.group(3)
+
+    return MYPY_IGNORE_DIRECTIVE_RULE_REGEX.sub(
+        replace_rule_name_but_leave_surrounding_characters, line
+    )
+
+
 class SpellingChecker(BaseTokenChecker):
     """Check spelling in comments and docstrings."""
 
@@ -332,6 +348,7 @@ class SpellingChecker(BaseTokenChecker):
             starts_with_comment = False
 
         line = _strip_code_flanked_in_backticks(line)
+        line = _strip_mypy_ignore_directive_rule(line)
 
         for word, word_start_at in self.tokenizer(line.strip()):
             word_start_at += initial_space
diff --git a/tests/checkers/unittest_spelling.py b/tests/checkers/unittest_spelling.py
index 9939ccb35..de1a95610 100644
--- a/tests/checkers/unittest_spelling.py
+++ b/tests/checkers/unittest_spelling.py
@@ -310,7 +310,7 @@ class TestSpellingChecker(CheckerTestCase):  # pylint:disable=too-many-public-me
             ("noqa", ":", "flake8 / zimports directive"),
             ("nosec", "", "bandit directive"),
             ("isort", ":skip", "isort directive"),
-            ("mypy", ":", "mypy directive"),
+            ("mypy", ":", "mypy top of file directive"),
         ),
     )
     def test_skip_tool_directives_at_beginning_of_comments_but_still_raise_error_if_directive_appears_later_in_comment(  # pylint:disable=unused-argument
@@ -374,6 +374,24 @@ class TestSpellingChecker(CheckerTestCase):  # pylint:disable=too-many-public-me
             self.checker.process_tokens(_tokenize_str(full_comment))
 
     @skip_on_missing_package_or_dict
+    @set_config(spelling_dict=spell_dict)
+    def test_skip_mypy_ignore_directives(self):
+        full_comment = "# type: ignore[attr-defined] attr"
+        with self.assertAddsMessages(
+            MessageTest(
+                "wrong-spelling-in-comment",
+                line=1,
+                args=(
+                    "attr",
+                    full_comment,
+                    "   ^^^^",
+                    self._get_msg_suggestions("attr"),
+                ),
+            )
+        ):
+            self.checker.process_tokens(_tokenize_str(full_comment))
+
+    @skip_on_missing_package_or_dict
     @set_config(
         spelling_dict=spell_dict,
         spelling_ignore_comment_directives="newdirective:,noqa",