Don't fail on mypy-style '# type: ignore[code, ...]' comments

Fixes #485

PiperOrigin-RevId: 289758806

pytype/directors.py

@@ -10,6 +10,7 @@
 from six import moves
 
 _DIRECTIVE_RE = re.compile(r"#\s*(pytype|type)\s*:\s?([^#]*)")
+_IGNORE_RE = re.compile(r"^ignore(\[.+\])?$")
 _CLOSING_BRACKETS_RE = re.compile(r"^(\s*[]})]\s*)+(#.*)?$")
 _WHITESPACE_RE = re.compile(r"^\s*(#.*)?$")
 _CLASS_OR_FUNC_RE = re.compile(r"^(def|class)\s")
@@ -229,7 +230,9 @@ def _process_type(self, lineno, code, data, is_nested):
       self._errorlog.invalid_directive(
           self._filename, lineno,
           "Multiple type comments on the same line.")
-    if data == "ignore":
+    # Also supports mypy-style ignore[code, ...] syntax, treated as regular
+    # ignores.
+    if _IGNORE_RE.match(data):
       if not code:
         self._ignore.start_range(lineno, True)
       else:

pytype/directors_test.py

@@ -132,6 +132,16 @@ def test_ignore_one_line(self):
     self._should_report(False, 3)
     self._should_report(True, 4)
 
+  def test_ignore_one_line_mypy_style(self):
+    self._create("""
+    # line 2
+    x = 123  # type: ignore[arg-type]
+    # line 4
+    """)
+    self._should_report(True, 2)
+    self._should_report(False, 3)
+    self._should_report(True, 4)
+
   def test_utf8(self):
     self._create("""
     x = u"abc□def\n"