fix: escape square brackets in patterns to match literal bracket file…

src/watchdog/utils/patterns.py

@@ -37,6 +37,14 @@ def _get_sep(path: PurePath) -> str:
 
 
 def _full_match(path: PurePath, pattern: str) -> bool:
+    # Escape square brackets in the pattern so they match file/directory names
+    # containing literal brackets rather than being interpreted as character
+    # classes.  For example, the pattern "[test].txt" should match a file
+    # literally named "[test].txt", not a file like "t.txt" (where [test] is a
+    # character class matching t, e, s).  Replacing "[" with "[[[]" makes the
+    # opening bracket literal in fnmatch/glob syntax.
+    # See: https://github.com/gorakhargosh/watchdog/issues/991
+    pattern = pattern.replace("[", "[[[]")
     try:
         return path.full_match(pattern)
     except AttributeError:

tests/test_patterns.py

@@ -79,3 +79,19 @@ def test_match_any_paths(included_patterns, excluded_patterns, case_sensitive, e
         )
         == expected
     )
+
+
+@pytest.mark.parametrize(
+    ("raw_path", "included_patterns", "expected"),
+    [
+        # Regression tests for https://github.com/gorakhargosh/watchdog/issues/991:
+        # square brackets in patterns must match literal bracket characters
+        # instead of being interpreted as fnmatch character classes.
+        ("/users/gorakhargosh/[test].txt", {"**/[test].txt"}, True),
+        ("/users/gorakhargosh/t.txt", {"**/[test].txt"}, False),
+        ("/users/gorakhargosh/file[1].py", {"**/file[1].py"}, True),
+        ("/users/gorakhargosh/file1.py", {"**/file[1].py"}, False),
+    ],
+)
+def test_match_path_literal_brackets(raw_path, included_patterns, expected):
+    assert _match_path(raw_path, included_patterns, set(), case_sensitive=True) is expected