Better output on wrong argument given to Ruff

prospector/formatters/grouped.py

@@ -18,8 +18,8 @@ def render_messages(self) -> str:
         groups: dict[Path, dict[int, list[Message]]] = defaultdict(lambda: defaultdict(list))
 
         for message in self.messages:
-            assert message.location.line is not None
-            groups[self._make_path(message.location)][message.location.line].append(message)
+            line = message.location.line
+            groups[self._make_path(message.location)][-1 if line is None else line].append(message)
 
         for filename in sorted(groups.keys()):
             output.append(str(filename))

prospector/formatters/pylint.py

@@ -28,16 +28,26 @@ def render_messages(self) -> list[str]:
             # Missing function docstring
 
             template_location = (
-                "%(path)s"
+                ""
+                if message.location.path is None
+                else "%(path)s"
                 if message.location.line is None
                 else "%(path)s:%(line)s"
                 if message.location.character is None
                 else "%(path)s:%(line)s:%(character)s"
             )
             template_code = (
-                "%(code)s(%(source)s)" if message.location.function is None else "[%(code)s(%(source)s), %(function)s]"
+                "(%(source)s)"
+                if message.code is None
+                else "%(code)s(%(source)s)"
+                if message.location.function is None
+                else "[%(code)s(%(source)s), %(function)s]"
+            )
+            template = (
+                f"{template_location}: {template_code}: %(message)s"
+                if template_location
+                else f"{template_code}: %(message)s"
             )
-            template = f"{template_location}: {template_code}: %(message)s"
 
             output.append(
                 template

prospector/message.py

@@ -5,7 +5,7 @@
 class Location:
     def __init__(
         self,
-        path: Union[Path, str],
+        path: Optional[Union[Path, str]],
         module: Optional[str],
         function: Optional[str],
         line: Optional[int],
@@ -15,6 +15,8 @@ def __init__(
             self._path = path.absolute()
         elif isinstance(path, str):
             self._path = Path(path).absolute()
+        elif path is None:
+            self._path = None
         else:
             raise ValueError
         self.module = module or None
@@ -23,13 +25,15 @@ def __init__(
         self.character = None if character == -1 else character
 
     @property
-    def path(self) -> Path:
+    def path(self) -> Optional[Path]:
         return self._path
 
-    def absolute_path(self) -> Path:
+    def absolute_path(self) -> Optional[Path]:
         return self._path
 
-    def relative_path(self, root: Optional[Path]) -> Path:
+    def relative_path(self, root: Optional[Path]) -> Optional[Path]:
+        if self._path is None:
+            return None
         return self._path.relative_to(root) if root else self._path
 
     def __repr__(self) -> str:

prospector/postfilter.py

@@ -29,7 +29,7 @@ def filter_messages(filepaths: List[Path], messages: List[Message]) -> List[Mess
     filtered = []
     for message in messages:
         # first get rid of the pylint informational messages
-        relative_message_path = Path(message.location.path)
+        relative_message_path = None if message.location.path is None else Path(message.location.path)
 
         if message.source == "pylint" and message.code in (
             "suppressed-message",

prospector/tools/ruff/__init__.py

@@ -47,6 +47,16 @@ def run(self, found_files: FileFinder) -> list[Message]:
         completed_process = subprocess.run(  # noqa: S603
             [self.ruff_bin, *self.ruff_args, *found_files.python_modules], capture_output=True
         )
+        if not completed_process.stdout:
+            messages.append(
+                Message(
+                    "ruff",
+                    "",
+                    Location(None, None, None, None, None),
+                    completed_process.stderr.decode(),
+                )
+            )
+            return messages
         for message in json.loads(completed_process.stdout):
             sub_message = {}
             if message.get("url"):

tests/test_message.py

@@ -25,7 +25,6 @@ def test_strings_or_paths(self):
 
     def test_bad_path_input(self):
         self.assertRaises(ValueError, Location, 3.2, "module", "func", 1, 2)
-        self.assertRaises(ValueError, Location, None, "module", "func", 1, 2)
 
 
 class LocationOrderTest(TestCase):