config: remove unnecessary code from Argument

The `processopt` callback currently doesn't update any fields, so this
code is not needed. And since we definitely do not want to extend the
use of `processopt`, it's fine to remove.

Author: bluetech

src/_pytest/config/argparsing.py

@@ -335,12 +335,6 @@ def names(self) -> list[str]:
         return self._short_opts + self._long_opts
 
     def attrs(self) -> Mapping[str, Any]:
-        # Update any attributes set by processopt.
-        for attr in ("default", "dest", "help", self.dest):
-            try:
-                self._attrs[attr] = getattr(self, attr)
-            except AttributeError:
-                pass
         return self._attrs
 
     def _set_opt_strings(self, opts: Sequence[str]) -> None:

testing/test_parseopt.py

@@ -63,14 +63,6 @@ def test_argument_type(self) -> None:
         )
         assert argument.type is str
 
-    def test_argument_processopt(self) -> None:
-        argument = parseopt.Argument("-t", type=int)
-        argument.default = 42
-        argument.dest = "abc"
-        res = argument.attrs()
-        assert res["default"] == 42
-        assert res["dest"] == "abc"
-
     def test_group_add_and_get(self, parser: parseopt.Parser) -> None:
         group = parser.getgroup("hello")
         assert group.name == "hello"
@@ -191,24 +183,6 @@ def test_parse_split_positional_arguments(self, parser: parseopt.Parser) -> None
         assert args.R is True
         assert args.S is False
 
-    def test_parse_defaultgetter(self) -> None:
-        def defaultget(option):
-            if not hasattr(option, "type"):
-                return
-            if option.type is int:
-                option.default = 42
-            elif option.type is str:
-                option.default = "world"
-
-        parser = parseopt.Parser(processopt=defaultget, _ispytest=True)
-        parser.addoption("--this", dest="this", type=int, action="store")
-        parser.addoption("--hello", dest="hello", type=str, action="store")
-        parser.addoption("--no", dest="no", action="store_true")
-        option = parser.parse([])
-        assert option.hello == "world"
-        assert option.this == 42
-        assert option.no is False
-
     def test_drop_short_helper(self) -> None:
         parser = argparse.ArgumentParser(
             formatter_class=parseopt.DropShorterLongHelpFormatter, allow_abbrev=False