Add error code to Mypy message

Author: patrick91

mypy_silent/cli.py

@@ -6,7 +6,7 @@
 from mypy_silent.maho import add_type_ignore_comment
 from mypy_silent.maho import remove_type_ignore_comment
 from mypy_silent.parser import FilePosition
-from mypy_silent.parser import get_info_form_mypy_output
+from mypy_silent.parser import get_info_from_mypy_output
 from mypy_silent.parser import UNUSED_IGNORE_MESSAGES
 from mypy_silent.utils import get_lines
 
@@ -17,19 +17,19 @@ def mypy_silent(
     ),
 ) -> None:
     lines = get_lines(mypy_output_file)
-    infos = get_info_form_mypy_output(lines)
+    infos = get_info_from_mypy_output(lines)
     processed: Set[FilePosition] = set()
     for info in infos:
         if info.position in processed:
             continue
-        with open(info.position.filename) as f:
+        with open(info.position.filename, "r") as f:
             file_contents = f.readlines()
 
         old_content = file_contents[info.position.line - 1]
         if info.message in UNUSED_IGNORE_MESSAGES:
             new_content = remove_type_ignore_comment(old_content)
         else:
-            new_content = add_type_ignore_comment(old_content)
+            new_content = add_type_ignore_comment(old_content, error_code=info.error_code)
         file_contents[info.position.line - 1] = new_content
         with open(info.position.filename, "w") as f:
             f.writelines(file_contents)

mypy_silent/maho.py

@@ -1,9 +1,18 @@
-def add_type_ignore_comment(line: str) -> str:
+from typing import Optional
+
+
+def add_type_ignore_comment(line: str, error_code: Optional[str]) -> str:
     # Workarounds for https://mypy.readthedocs.io/en/stable/common_issues.html#silencing-linters
+
+    type_ignore_comment = "# type: ignore"
+
+    if error_code:
+        type_ignore_comment += f"[{error_code}]"
+
     if "# noqa" in line:
-        return line.replace("# noqa", "# type: ignore # noqa", 1)
+        return line.replace("# noqa", f"{type_ignore_comment} # noqa", 1)
     content_without_crlf = line.rstrip("\r\n")
-    return content_without_crlf + "  # type: ignore" + line[len(content_without_crlf) :]
+    return content_without_crlf + f"  {type_ignore_comment}" + line[len(content_without_crlf) :]
 
 
 def remove_type_ignore_comment(line: str) -> str:

mypy_silent/parser.py

@@ -1,13 +1,11 @@
 import re
-from typing import FrozenSet
 from typing import Iterable
 from typing import NamedTuple
-
+from typing import FrozenSet
+from typing import Optional
 from typing_extensions import Final
 
-UNUSED_IGNORE_MESSAGES: Final[FrozenSet[str]] = frozenset(
-    {"error: unused 'type: ignore' comment", 'error: unused "type: ignore" comment'}
-)
+UNUSED_IGNORE_MESSAGES: Final[FrozenSet[str]] = frozenset({"error: unused 'type: ignore' comment", 'error: unused "type: ignore" comment'})
 
 
 class FilePosition(NamedTuple):
@@ -18,20 +16,22 @@ class FilePosition(NamedTuple):
 class MypyMessage(NamedTuple):
     position: FilePosition
     message: str
+    error_code: Optional[str]
 
 
-_mypy_output_re = re.compile(r"^([^:]+):(\d+):(.+)$")
+_mypy_output_re = re.compile(r"^(?P<filename>[^:]+):(?P<line>\d+):(?P<message>.+?)(\[(?P<error_code>[a-z-]+)\])?$")
 
 
-def get_info_form_mypy_output(lines: Iterable[str]) -> Iterable[MypyMessage]:
+def get_info_from_mypy_output(lines: Iterable[str]) -> Iterable[MypyMessage]:
     for line in lines:
         line = line.strip()
         match = _mypy_output_re.match(line)
         if match:
             yield MypyMessage(
                 position=FilePosition(
-                    filename=match.group(1).strip(),
-                    line=int(match.group(2)),
+                    filename=match.group("filename").strip(),
+                    line=int(match.group("line")),
                 ),
-                message=match.group(3).strip(),
+                message=match.group("message").strip(),
+                error_code=match.group("error_code"),
             )

tests/test_maho.py

@@ -15,7 +15,13 @@
     ),
 )
 def test_add_type_ignore_comment(input: str, output: str) -> None:
-    assert add_type_ignore_comment(input) == output
+    assert add_type_ignore_comment(input, error_code=None) == output
+
+
+def test_add_type_ignore_comment_with_error_code() -> None:
+    input = "host, port, protocol = m.groups()\r\n"
+    output = "host, port, protocol = m.groups()\r\n  # type: ignore[misc]"
+    assert add_type_ignore_comment(input, error_code="misc") == output
 
 
 @pytest.mark.parametrize(

tests/test_parser.py

@@ -3,7 +3,7 @@
 import pytest
 
 from mypy_silent.parser import FilePosition
-from mypy_silent.parser import get_info_form_mypy_output
+from mypy_silent.parser import get_info_from_mypy_output
 from mypy_silent.parser import MypyMessage
 
 
@@ -14,20 +14,22 @@
         (
             [
                 "utils/template.py:49: error: Cannot assign to a method",
-                "utils/template.py:53: error: Statement is unreachable",
+                "utils/template.py:53: error: Statement is unreachable [unreachable]",
             ],
             [
                 MypyMessage(
                     position=FilePosition(filename="utils/template.py", line=49),
                     message="error: Cannot assign to a method",
+                    error_code=None,
                 ),
                 MypyMessage(
                     position=FilePosition(filename="utils/template.py", line=53),
                     message="error: Statement is unreachable",
+                    error_code="unreachable",
                 ),
             ],
         ),
     ),
 )
-def test_get_info_form_mypy_output(input: List[str], output: List[MypyMessage]) -> None:
-    assert list(get_info_form_mypy_output(input)) == output
+def test_get_info_from_mypy_output(input: List[str], output: List[MypyMessage]) -> None:
+    assert list(get_info_from_mypy_output(input)) == output