Add an error code for this new warning

Author: PeterJCLaw

mypy/errorcodes.py

@@ -133,6 +133,12 @@ def __str__(self) -> str:
 NAME_MATCH: Final = ErrorCode(
     "name-match", "Check that type definition has consistent naming", "General"
 )
+IGNORE_WITHOUT_CODE: Final = ErrorCode(
+    "ignore-without-code",
+    "Warn about '# type: ignore' comments which do not have error codes",
+    "General",
+    default_enabled=False,
+)
 
 
 # Syntax errors are often blocking.

mypy/errors.py

@@ -516,8 +516,8 @@ def generate_ignore_without_code_errors(self,
             message = f'"type: ignore" comment without error code{codes_hint}'
             # Don't use report since add_error_info will ignore the error!
             info = ErrorInfo(self.import_context(), file, self.current_module(), None,
-                             None, line, -1, 'error', message,
-                             None, False, False, False)
+                             None, line, -1, 'error', message, codes.IGNORE_WITHOUT_CODE,
+                             False, False, False)
             self._add_error_info(file, info)
 
     def num_messages(self) -> int:

test-data/unit/check-errorcodes.test

@@ -137,8 +137,8 @@ x # type: ignore[name-defined, attr-defined] # E: Unused "type: ignore[attr-defi
 
 [case testErrorCodeMissingWhenRequired]
 # flags: --warn-ignores-without-codes
-"x" # type: ignore # E: "type: ignore" comment without error code
-y # type: ignore # E: "type: ignore" comment without error code (hint: add [name-defined])
+"x" # type: ignore # E: "type: ignore" comment without error code [ignore-without-code]
+y # type: ignore # E: "type: ignore" comment without error code (hint: add [name-defined])  [ignore-without-code]
 
 [case testErrorCodeMissingDoesntTrampleUnusedIgnoresWarning]
 # flags: --warn-ignores-without-codes --warn-unused-ignores