Make test decorator use ``checker.set_option()``

This makes unittests with options mimick the normal option setting
behaviour. It also adds ``set_config_directly()`` for those cases where
this is not possible.

2 files changed, 41 insertions, 2 deletions

diff --git a/pylint/testutils/decorator.py b/pylint/testutils/decorator.py
index 44d186d1e..d635c7f3c 100644
--- a/pylint/testutils/decorator.py
+++ b/pylint/testutils/decorator.py
@@ -2,7 +2,9 @@
 # For details: https://github.com/PyCQA/pylint/blob/main/LICENSE
 
 import functools
+import optparse  # pylint: disable=deprecated-module
 
+from pylint.lint import PyLinter
 from pylint.testutils.checker_test_case import CheckerTestCase
 
 
@@ -16,6 +18,42 @@ def set_config(**kwargs):
     def _wrapper(fun):
         @functools.wraps(fun)
         def _forward(self, *args, **test_function_kwargs):
+            try:
+                for key, value in kwargs.items():
+                    self.checker.set_option(key.replace("_", "-"), value)
+            except optparse.OptionError:
+                # Check if option is one of the base options of the PyLinter class
+                for key, value in kwargs.items():
+                    self.checker.set_option(
+                        key.replace("_", "-"),
+                        value,
+                        optdict=dict(PyLinter.make_options()),
+                    )
+            if isinstance(self, CheckerTestCase):
+                # reopen checker in case, it may be interested in configuration change
+                self.checker.open()
+            fun(self, *args, **test_function_kwargs)
+
+        return _forward
+
+    return _wrapper
+
+
+def set_config_directly(**kwargs):
+    """Decorator for setting config values on a checker without validation.
+
+    Some options should be declared in two different checkers. This is
+    impossible without duplicating the option key. For example:
+    "no-docstring-rgx" in DocstringParameterChecker & DocStringChecker
+    This decorator allows to directly set such options.
+
+    Passing the args and kwargs back to the test function itself
+    allows this decorator to be used on parametrized test cases.
+    """
+
+    def _wrapper(fun):
+        @functools.wraps(fun)
+        def _forward(self, *args, **test_function_kwargs):
             for key, value in kwargs.items():
                 setattr(self.checker.config, key, value)
             if isinstance(self, CheckerTestCase):
diff --git a/tests/extensions/test_check_docs.py b/tests/extensions/test_check_docs.py
index 6676c13b4..65d077aed 100644
--- a/tests/extensions/test_check_docs.py
+++ b/tests/extensions/test_check_docs.py
@@ -31,6 +31,7 @@ from astroid import nodes
 
 from pylint.extensions.docparams import DocstringParameterChecker
 from pylint.testutils import CheckerTestCase, MessageTest, set_config
+from pylint.testutils.decorator import set_config_directly
 
 
 class TestParamDocChecker(CheckerTestCase):
@@ -2324,7 +2325,7 @@ class TestParamDocChecker(CheckerTestCase):
         ):
             self.checker.visit_functiondef(node)
 
-    @set_config(no_docstring_rgx=r"^_(?!_).*$")
+    @set_config_directly(no_docstring_rgx=r"^_(?!_).*$")
     def test_skip_no_docstring_rgx(self) -> None:
         """Example of a function that matches the default 'no-docstring-rgx' config option
 
@@ -2342,7 +2343,7 @@ class TestParamDocChecker(CheckerTestCase):
         with self.assertNoMessages():
             self.checker.visit_functiondef(node)
 
-    @set_config(docstring_min_length=3)
+    @set_config_directly(docstring_min_length=3)
     def test_skip_docstring_min_length(self) -> None:
         """Example of a function that is less than 'docstring-min-length' config option