[#455] Raising an exception if bad mypy options are found

CHANGELOG.rst

@@ -15,6 +15,7 @@ Just say no to bugs.
 
 * Stopped the ProfileValidator tool raising errors about ``pep8`` and ``pep257`` sections being unknown. Instead, they raise deprecated warnings.
 * Blending works again - for example, pylint and pycodestyle errors representing the same thing are combined. After renaming pep8 to pycodestyle, this only worked when using legacy names.
+* Unrecognised Mypy options now raise an exception instead of silently carrying on - `#455 <https://github.com/PyCQA/prospector/issues/455>`_
 
 **Tidyup**:
 

prospector/tools/exceptions.py

@@ -0,0 +1,3 @@
+class BadToolConfig(Exception):
+    def __init__(self, tool_name: str, message: str):
+        super().__init__(f"Bad option value found for tool {tool_name}: {message}")

prospector/tools/mypy/__init__.py

@@ -5,8 +5,20 @@
 
 __all__ = ("MypyTool",)
 
-
-MYPY_OPTIONS = ["allow", "check", "disallow", "no-check", "no-warn", "warn"]
+from prospector.tools.exceptions import BadToolConfig
+
+LIST_OPTIONS = ["allow", "check", "disallow", "no-check", "no-warn", "warn"]
+VALID_OPTIONS = LIST_OPTIONS + [
+    "strict",
+    "follow-imports",
+    "ignore-missing-imports",
+    "implicit-optional",
+    "strict-optional",
+    "platform",
+    "python-2-mode",
+    "python-version",
+    "namespace-packages",
+]
 
 
 def format_message(message):
@@ -47,6 +59,13 @@ def __init__(self, *args, **kwargs):
     def configure(self, prospector_config, _):
         options = prospector_config.tool_options("mypy")
 
+        for option_key in options.keys():
+            if option_key not in VALID_OPTIONS:
+                url = "https://github.com/PyCQA/prospector/blob/master/prospector/tools/mypy/__init__.py"
+                raise BadToolConfig(
+                    "mypy", f"Option {option_key} is not valid. " f"See the list of possible options: {url}"
+                )
+
         strict = options.get("strict", False)
 
         follow_imports = options.get("follow-imports", "normal")
@@ -84,7 +103,7 @@ def configure(self, prospector_config, _):
         if namespace_packages:
             self.options.append("--namespace-packages")
 
-        for list_option in MYPY_OPTIONS:
+        for list_option in LIST_OPTIONS:
             for entry in options.get(list_option, []):
                 self.options.append(f"--{list_option}-{entry}")
 

tests/tools/mypy/test_mypy_tool.py

@@ -1,6 +1,11 @@
+from pathlib import Path
 from unittest import SkipTest, TestCase
+from unittest.mock import patch
 
+from prospector.config import ProspectorConfig
+from prospector.finder import find_python
 from prospector.message import Location, Message
+from prospector.tools.exceptions import BadToolConfig
 
 try:
     from prospector.tools.mypy import format_message
@@ -9,6 +14,22 @@
 
 
 class TestMypyTool(TestCase):
+    @staticmethod
+    def _get_config(profile_name: str) -> ProspectorConfig:
+        profile_path = Path(__file__).parent / f"test_profiles/{profile_name}.yaml"
+        with patch("sys.argv", ["prospector", "--profile", str(profile_path.absolute())]):
+            return ProspectorConfig()
+
+    def test_unrecognised_options(self):
+        finder = find_python([], [], True, Path(__file__).parent.absolute())
+        self.assertRaises(BadToolConfig, self._get_config("mypy_bad_options").get_tools, finder)
+
+    def test_good_options(self):
+        finder = find_python([], [], True, Path(__file__).parent.absolute())
+        self._get_config("mypy_good_options").get_tools(finder)
+
+
+class TestMypyMessageFormat(TestCase):
     def test_format_message_with_character(self):
         location = Location(path="file.py", module=None, function=None, line=17, character=2)
         expected = Message(source="mypy", code="error", location=location, message="Important error")

tests/tools/mypy/test_profiles/mypy_bad_options.yaml

@@ -0,0 +1,5 @@
+
+mypy:
+  run: yes
+  options:
+    warn-unreachable: true

tests/tools/mypy/test_profiles/mypy_good_options.yaml

@@ -0,0 +1,6 @@
+
+mypy:
+  run: yes
+  options:
+    warn:
+      - unreachable