Refactor and typing of OutputLine (#5060)

Co-authored-by: Marc Mueller <30130371+cdce8p@users.noreply.github.com>

pylint/testutils/output_line.py

@@ -2,10 +2,13 @@
 # For details: https://github.com/PyCQA/pylint/blob/main/LICENSE
 
 import collections
-from typing import Any, NamedTuple
+from typing import Any, NamedTuple, Optional, Sequence, Tuple, Union
+
+from astroid import nodes
 
-from pylint import interfaces
 from pylint.constants import PY38_PLUS
+from pylint.interfaces import HIGH, UNDEFINED, Confidence
+from pylint.message.message import Message
 from pylint.testutils.constants import UPDATE_OPTION
 
 
@@ -16,19 +19,30 @@ class MessageTest(
 ):
     """Used to test messages produced by pylint. Class name cannot start with Test as pytest doesn't allow constructors in test classes."""
 
-    def __new__(cls, msg_id, line=None, node=None, args=None, confidence=None):
+    def __new__(
+        cls,
+        msg_id: str,
+        line: Optional[int] = None,
+        node: Optional[nodes.NodeNG] = None,
+        args: Any = None,
+        confidence: Optional[Confidence] = None,
+    ) -> "MessageTest":
         return tuple.__new__(cls, (msg_id, line, node, args, confidence))
 
-    def __eq__(self, other):
+    def __eq__(self, other: object) -> bool:
         if isinstance(other, MessageTest):
             if self.confidence and other.confidence:
                 return super().__eq__(other)
-            return self[:-1] == other[:-1]
+            return tuple(self[:-1]) == tuple(other[:-1])
         return NotImplemented  # pragma: no cover
 
 
 class MalformedOutputLineException(Exception):
-    def __init__(self, row, exception):
+    def __init__(
+        self,
+        row: Union[Sequence[str], str],
+        exception: Exception,
+    ) -> None:
         example = "msg-symbolic-name:42:27:MyClass.my_function:The message"
         other_example = "msg-symbolic-name:7:42::The message"
         expected = [
@@ -62,39 +76,42 @@ def __init__(self, row, exception):
 class OutputLine(NamedTuple):
     symbol: str
     lineno: int
-    column: str
-    object: Any
+    column: int
+    object: str
     msg: str
-    confidence: interfaces.Confidence
+    confidence: str
 
     @classmethod
-    def from_msg(cls, msg):
-        column = cls.get_column(msg.column)
+    def from_msg(cls, msg: Message) -> "OutputLine":
+        column = cls._get_column(msg.column)
         return cls(
             msg.symbol,
             msg.line,
             column,
             msg.obj or "",
             msg.msg.replace("\r\n", "\n"),
-            msg.confidence.name
-            if msg.confidence != interfaces.UNDEFINED
-            else interfaces.HIGH.name,
+            msg.confidence.name if msg.confidence != UNDEFINED else HIGH.name,
         )
 
-    @classmethod
-    def get_column(cls, column):
+    @staticmethod
+    def _get_column(column: str) -> int:
         if not PY38_PLUS:
-            return ""  # pragma: no cover
-        return str(column)
+            # We check the column only for the new better ast parser introduced in python 3.8
+            return 0  # pragma: no cover
+        return int(column)
 
     @classmethod
-    def from_csv(cls, row):
+    def from_csv(cls, row: Union[Sequence[str], str]) -> "OutputLine":
         try:
-            confidence = row[5] if len(row) == 6 else interfaces.HIGH.name
-            column = cls.get_column(row[2])
-            return cls(row[0], int(row[1]), column, row[3], row[4], confidence)
+            if isinstance(row, Sequence):
+                column = cls._get_column(row[2])
+                if len(row) == 5:
+                    return cls(row[0], int(row[1]), column, row[3], row[4], HIGH.name)
+                if len(row) == 6:
+                    return cls(row[0], int(row[1]), column, row[3], row[4], row[5])
+            raise IndexError
         except Exception as e:
             raise MalformedOutputLineException(row, e) from e
 
-    def to_csv(self):
-        return tuple(self)
+    def to_csv(self) -> Tuple[str, str, str, str, str, str]:
+        return tuple(str(i) for i in self)  # type: ignore # pylint: disable=not-an-iterable

tests/testutils/test_output_line.py

@@ -3,14 +3,15 @@
 
 # pylint: disable=redefined-outer-name
 
-from typing import Callable, List, Optional
+from typing import Callable, Optional
 
 import pytest
 
 from pylint.constants import PY38_PLUS
 from pylint.interfaces import HIGH, INFERENCE, Confidence
 from pylint.message import Message
 from pylint.testutils.output_line import MalformedOutputLineException, OutputLine
+from pylint.typing import MessageLocationTuple
 
 
 @pytest.fixture()
@@ -19,14 +20,14 @@ def inner(confidence: Confidence = HIGH) -> Message:
         return Message(
             symbol="missing-docstring",
             msg_id="C0123",
-            location=[  # type: ignore
+            location=MessageLocationTuple(
                 "abspath",
                 "path",
                 "module",
                 "obj",
-                "line",
-                "column",
-            ],
+                1,
+                2,
+            ),
             msg="msg",
             confidence=confidence,
         )
@@ -37,11 +38,11 @@ def inner(confidence: Confidence = HIGH) -> Message:
 def test_output_line() -> None:
     output_line = OutputLine(
         symbol="missing-docstring",
-        lineno=0,
-        column="0",
+        lineno=1,
+        column=2,
         object="",
         msg="Missing docstring's bad.",
-        confidence=HIGH,
+        confidence=HIGH.name,
     )
     assert output_line.symbol == "missing-docstring"
 
@@ -56,10 +57,10 @@ def test_output_line_from_message(message: Callable) -> None:
 def test_output_line_to_csv(confidence: Confidence, message: Callable) -> None:
     output_line = OutputLine.from_msg(message(confidence))
     csv = output_line.to_csv()
-    expected_column = "column" if PY38_PLUS else ""
+    expected_column = "2" if PY38_PLUS else "0"
     assert csv == (
         "missing-docstring",
-        "line",
+        "1",
         expected_column,
         "obj",
         "msg",
@@ -84,10 +85,10 @@ def test_output_line_from_csv_error() -> None:
     "confidence,expected_confidence", [[None, "HIGH"], ["INFERENCE", "INFERENCE"]]
 )
 def test_output_line_from_csv(
-    confidence: Optional[str], expected_confidence: Confidence
+    confidence: Optional[str], expected_confidence: str
 ) -> None:
     if confidence:
-        proper_csv: List[str] = [
+        proper_csv = [
             "missing-docstring",
             "1",
             "2",
@@ -98,7 +99,7 @@ def test_output_line_from_csv(
     else:
         proper_csv = ["missing-docstring", "1", "2", "obj", "msg"]
     output_line = OutputLine.from_csv(proper_csv)
-    expected_column = "2" if PY38_PLUS else ""
+    expected_column = 2 if PY38_PLUS else 0
     assert output_line == OutputLine(
         symbol="missing-docstring",
         lineno=1,