Check documentation examples for fatal errors (#6475)

doc/data/messages/a/assert-on-string-literal/details.rst

@@ -0,0 +1 @@
+Directly asserting a string literal will always pass.

doc/data/messages/a/assert-on-string-literal/good.py

@@ -1,2 +1,4 @@
 def test():
-    # Nothing, as an assert of a string literal will always pass
+    result = "result"
+    expected = "expected"
+    assert result == expected

doc/data/messages/r/redundant-unittest-assert/details.rst

@@ -0,0 +1 @@
+Directly asserting a string literal will always pass.

doc/data/messages/r/redundant-unittest-assert/good.py

@@ -3,4 +3,5 @@
 
 class DummyTestCase(unittest.TestCase):
     def test_dummy(self):
-        # Nothing, as an assert of a string literal will always pass
+        actual = "test_result"
+        self.assertEqual(actual, "expected")

doc/test_messages_documentation.py

@@ -91,7 +91,7 @@ def __init__(self, test_file: Tuple[str, Path]) -> None:
             args_list=[
                 str(test_file[1]),
                 "--disable=all",
-                f"--enable={test_file[0]}",
+                f"--enable={test_file[0]},astroid-error,fatal,syntax-error",
             ],
             reporter=_test_reporter,
             config_file=config_file,

pylint/testutils/lint_module_test.py

@@ -71,6 +71,7 @@ def __init__(
                 # Always enable fatal errors
                 messages_to_enable.add("astroid-error")
                 messages_to_enable.add("fatal")
+                messages_to_enable.add("syntax-error")
             args.extend(["--disable=all", f"--enable={','.join(messages_to_enable)}"])
         _config_initialization(
             self._linter, args_list=args, config_file=rc_file, reporter=_test_reporter

tests/testutils/test_functional_testutils.py

@@ -62,6 +62,7 @@ def test_minimal_messages_config_enabled(pytest_config) -> None:
             # Always enable fatal errors: important not to have false negatives
             "astroid-error",
             "fatal",
+            "syntax-error",
         )
     )
     assert not mod_test._linter.is_message_enabled("unused-import")