skipping spellcheck for code flanked in backticks

3 files changed, 72 insertions, 34 deletions

diff --git a/ChangeLog b/ChangeLog
index feef5dcc2..c6e3068f0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -67,6 +67,14 @@ Release date: Undefined
 
 * Don't show ``DuplicateBasesError`` for attribute access
 
+* Allow code flanked in backticks to be skipped by spellchecker
+
+  Closes #4319
+
+* Allow Python tool directives (for black, flake8, zimports, isort, mypy, bandit, pycharm) at beginning of comments to be skipped by spellchecker
+
+  Closes #4320
+
 
 What's New in Pylint 2.7.4?
 ===========================
@@ -302,7 +310,7 @@ Release date: 2021-02-21
 
   Close #2738
 
-* Fix ``duplicate-code`` false positive when lines only contain whitespace and non-alphanumeric characters (e.g. parentheses, bracket, comman, etc.)
+* Fix ``duplicate-code`` false positive when lines only contain whitespace and non-alphanumeric characters (e.g. parentheses, bracket, comma, etc.)
 
 * Improve lint message for ``singleton-comparison`` with bools
 
diff --git a/pylint/checkers/spelling.py b/pylint/checkers/spelling.py
index dca7da3b5..b08ec772a 100644
--- a/pylint/checkers/spelling.py
+++ b/pylint/checkers/spelling.py
@@ -103,7 +103,7 @@ class WordsWithUnderscores(Filter):
 
 class RegExFilter(Filter):
     r"""Parent class for filters using regular expressions.
-    This filter skips any words the match the expression assigned to the class attribute `_pattern`
+    This filter skips any words the match the expression assigned to the class attribute ``_pattern``
 
     """
     _pattern: Pattern[str]
@@ -176,6 +176,24 @@ class ForwardSlashChunker(Chunker):
         raise StopIteration()
 
 
+CODE_FLANKED_IN_BACKTICK_REGEX = re.compile(r"(\s|^)(`{1,2})([^`]+)(\2)([^`]|$)")
+
+
+def _strip_code_flanked_in_backticks(line: str) -> str:
+    """Alter line so code flanked in backticks is ignored.
+
+    Pyenchant automatically strips backticks when parsing tokens, so this cannot be done at the individual filter level.
+
+    """
+
+    def replace_code_but_leave_surrounding_characters(match_obj) -> str:
+        return match_obj.group(1) + match_obj.group(5)
+
+    return CODE_FLANKED_IN_BACKTICK_REGEX.sub(
+        replace_code_but_leave_surrounding_characters, line
+    )
+
+
 class SpellingChecker(BaseTokenChecker):
     """Check spelling in comments and docstrings"""
 
@@ -323,6 +341,7 @@ class SpellingChecker(BaseTokenChecker):
                 "noqa",
                 "nosec",
                 "isort:skip",
+                "mypy:",
             ):
                 if line.startswith(" " + iter_directive):
                     line = line[(len(iter_directive) + 1) :]
@@ -330,6 +349,9 @@ class SpellingChecker(BaseTokenChecker):
             starts_with_comment = True
         else:
             starts_with_comment = False
+
+        line = _strip_code_flanked_in_backticks(line)
+
         for word, word_start_at in self.tokenizer(line.strip()):
             word_start_at += initial_space
             lower_cased_word = word.casefold()
diff --git a/tests/checkers/unittest_spelling.py b/tests/checkers/unittest_spelling.py
index dec6b19ee..0d946bc84 100644
--- a/tests/checkers/unittest_spelling.py
+++ b/tests/checkers/unittest_spelling.py
@@ -37,7 +37,9 @@ if enchant is not None:
         pass
 
 
-class TestSpellingChecker(CheckerTestCase):
+class TestSpellingChecker(
+    CheckerTestCase
+):  # pylint:disable=too-many-public-methods # This is a test case class, not sure why it would be relevant to have this pylint rule enforced for test case classes
     CHECKER_CLASS = spelling.SpellingChecker
 
     skip_on_missing_package_or_dict = pytest.mark.skipif(
@@ -303,37 +305,6 @@ class TestSpellingChecker(CheckerTestCase):
         ):
             self.checker.visit_classdef(stmt)
 
-    # @skip_on_missing_package_or_dict
-    # # @set_config(spelling_dict=spell_dict)
-    # @pytest.mark.parametrize(
-    #     "num_files,num_jobs,num_checkers",
-    #     [
-    #         (1, 2, 1),
-    #         (1, 2, 2),
-    #         (1, 2, 3),
-    #         (2, 2, 1),
-    #         (2, 2, 2),
-    #         (2, 2, 3),
-    #         (3, 2, 1),
-    #         (3, 2, 2),
-    #         (3, 2, 3),
-    #         (3, 1, 1),
-    #         (3, 1, 2),
-    #         (3, 1, 3),
-    #         (3, 5, 1),
-    #         (3, 5, 2),
-    #         (3, 5, 3),
-    #         (10, 2, 1),
-    #         (10, 2, 2),
-    #         (10, 2, 3),
-    #         (2, 10, 1),
-    #         (2, 10, 2),
-    #         (2, 10, 3),
-    #     ],
-    # )
-    # def test_compare_workers_to_single_proc(self, num_files, num_jobs, num_checkers):
-    #     assert True
-
     @skip_on_missing_package_or_dict
     @set_config(spelling_dict=spell_dict)
     @pytest.mark.parametrize(
@@ -351,6 +322,7 @@ class TestSpellingChecker(CheckerTestCase):
             ("noqa", ":", "flake8 / zimports directive"),
             ("nosec", "", "bandit directive"),
             ("isort", ":skip", "isort directive"),
+            ("mypy", ":", "mypy directive"),
         ),
     )
     def test_skip_tool_directives_at_beginning_of_comments_but_still_raise_error_if_directive_appears_later_in_comment(  # pylint:disable=unused-argument # Having the extra description parameter allows the description to show up in the pytest output as part of the test name when running parametrized tests
@@ -373,6 +345,42 @@ class TestSpellingChecker(CheckerTestCase):
 
     @skip_on_missing_package_or_dict
     @set_config(spelling_dict=spell_dict)
+    def test_skip_code_flanked_in_double_backticks(self):
+        full_comment = "# The function ``.qsize()`` .qsize()"
+        with self.assertAddsMessages(
+            Message(
+                "wrong-spelling-in-comment",
+                line=1,
+                args=(
+                    "qsize",
+                    full_comment,
+                    "                 ^^^^^",
+                    self._get_msg_suggestions("qsize"),
+                ),
+            )
+        ):
+            self.checker.process_tokens(_tokenize_str(full_comment))
+
+    @skip_on_missing_package_or_dict
+    @set_config(spelling_dict=spell_dict)
+    def test_skip_code_flanked_in_single_backticks(self):
+        full_comment = "# The function `.qsize()` .qsize()"
+        with self.assertAddsMessages(
+            Message(
+                "wrong-spelling-in-comment",
+                line=1,
+                args=(
+                    "qsize",
+                    full_comment,
+                    "                 ^^^^^",
+                    self._get_msg_suggestions("qsize"),
+                ),
+            )
+        ):
+            self.checker.process_tokens(_tokenize_str(full_comment))
+
+    @skip_on_missing_package_or_dict
+    @set_config(spelling_dict=spell_dict)
     def test_handle_words_joined_by_forward_slash(self):
         stmt = astroid.extract_node(
             '''