Extract CompilationConfig from config.py (#22524)

Signed-off-by: Harry Mellor <[email protected]>

Author: hmellor

tests/engine/test_arg_utils.py

@@ -93,32 +93,6 @@ class NestedConfig:
     """field"""
 
 
-@config
-@dataclass
-class FromCliConfig1:
-    field: int = 1
-    """field"""
-
-    @classmethod
-    def from_cli(cls, cli_value: str):
-        inst = cls(**json.loads(cli_value))
-        inst.field += 1
-        return inst
-
-
-@config
-@dataclass
-class FromCliConfig2:
-    field: int = 1
-    """field"""
-
-    @classmethod
-    def from_cli(cls, cli_value: str):
-        inst = cls(**json.loads(cli_value))
-        inst.field += 2
-        return inst
-
-
 @config
 @dataclass
 class DummyConfig:
@@ -144,10 +118,6 @@ class DummyConfig:
     """Dict which will be JSON in CLI"""
     nested_config: NestedConfig = field(default_factory=NestedConfig)
     """Nested config"""
-    from_cli_config1: FromCliConfig1 = field(default_factory=FromCliConfig1)
-    """Config with from_cli method"""
-    from_cli_config2: FromCliConfig2 = field(default_factory=FromCliConfig2)
-    """Different config with from_cli method"""
 
 
 @pytest.mark.parametrize(("type_hint", "expected"), [
@@ -199,9 +169,6 @@ def test_get_kwargs():
     assert json_tip in kwargs["json_tip"]["help"]
     # nested config should should construct the nested config
     assert kwargs["nested_config"]["type"]('{"field": 2}') == NestedConfig(2)
-    # from_cli configs should be constructed with the correct method
-    assert kwargs["from_cli_config1"]["type"]('{"field": 2}').field == 3
-    assert kwargs["from_cli_config2"]["type"]('{"field": 2}').field == 4
 
 
 @pytest.mark.parametrize(