Make sure that --generate-toml-config generates a valid file (#6564)

Author: DanielNoord

pylint/config/arguments_manager.py

@@ -665,7 +665,7 @@ def _generate_config_file(self) -> None:
             key=lambda x: (x.title != "Master", x.title),
         ):
             # Skip the options section with the --help option
-            if group.title == "options":
+            if group.title in {"options", "optional arguments", "Commands"}:
                 continue
 
             # Skip sections without options such as "positional arguments"
@@ -703,6 +703,12 @@ def _generate_config_file(self) -> None:
                     group_table.add(tomlkit.nl())
                     continue
 
+                # Skip deprecated options
+                if "kwargs" in optdict:
+                    assert isinstance(optdict["kwargs"], dict)
+                    if "new_names" in optdict["kwargs"]:
+                        continue
+
                 # Tomlkit doesn't support regular expressions
                 if isinstance(value, re.Pattern):
                     value = value.pattern
@@ -711,6 +717,10 @@ def _generate_config_file(self) -> None:
                 ):
                     value = [i.pattern for i in value]
 
+                # Handle tuples that should be strings
+                if optdict.get("type") == "py_version":
+                    value = ".".join(str(i) for i in value)
+
                 # Add to table
                 group_table.add(optname, value)
                 group_table.add(tomlkit.nl())

tests/test_self.py

@@ -14,6 +14,7 @@
 import re
 import subprocess
 import sys
+import tempfile
 import textwrap
 import warnings
 from collections.abc import Generator, Iterator
@@ -1384,6 +1385,7 @@ def test_generate_toml_config() -> None:
         )
         assert "[tool.pylint.master]" in process.stdout
         assert '"positional arguments"' not in process.stdout
+        assert '"optional arguments"' not in process.stdout
         assert 'preferred-modules = ["a:b"]' in process.stdout
 
         process_two = subprocess.run(
@@ -1394,6 +1396,19 @@ def test_generate_toml_config() -> None:
         )
         assert process.stdout == process_two.stdout
 
+        # Check that the generated file is valid
+        with tempfile.NamedTemporaryFile(
+            mode="w", suffix=".toml", delete=False
+        ) as temp:
+            filename = temp.name
+            temp.write(process.stdout)
+            runner = Run(
+                [join(HERE, "regrtest_data", "empty.py"), f"--rcfile={filename}"],
+                exit=False,
+            )
+            assert not runner.linter.msg_status
+        os.remove(filename)
+
     @staticmethod
     def test_generate_toml_config_disable_symbolic_names() -> None:
         """Test that --generate-toml-config puts symbolic names in the --disable option."""