Treat default values in function signature the same way as config kwargs

README.md

@@ -78,13 +78,13 @@ In configuronic, configurations are **closures** - callables that store both the
 import configuronic as cfn
 
 # Create a configuration
-@cfn.config(batch_size=32, lr=0.001)
-def create_optimizer(batch_size: int, lr: float):
-    return torch.optim.Adam(lr=lr)
+@cfn.config(lr=1e-3, weight_decay=0)
+def create_optimizer(lr: float, weight_decay: float):
+    return torch.optim.Adam(lr=lr, weight_decay=weight_decay)
 
 # Override and create variants
-fast_optimizer = create_optimizer.override(lr=0.01)
-large_batch_optimizer = create_optimizer.override(batch_size=128)
+fast_optimizer = create_optimizer.override(lr=1e-2)
+regularaized_optimizer = create_optimizer.override(weight_decay=1e-3)
 
 # Instantiate when needed
 optimizer = fast_optimizer.instantiate()

configuronic/config.py

@@ -190,6 +190,11 @@ def _get_creator_module() -> ModuleType | None:
     return module
 
 
+def _get_default_argument_values(target: Callable) -> dict[str, Any]:
+    sig = inspect.signature(target)
+    return {name: param.default for name, param in sig.parameters.items() if param.default != inspect.Parameter.empty}
+
+
 class Config:
     def __init__(self, target, *args, **kwargs):
         """
@@ -231,7 +236,7 @@ def __init__(self, target, *args, **kwargs):
         assert callable(target), f'Target must be callable, got object of type {type(target)}.'
         self.target = target
         self.args = [_resolve_value(arg) for arg in args]  # TODO: cover argument override with tests
-        self.kwargs = {}
+        self.kwargs = _get_default_argument_values(target)
         self._override_inplace(**kwargs)
 
         self._creator_module = _get_creator_module()

tests/test_cli.py

@@ -37,3 +37,15 @@ def identity(a, b):
         cfn.cli(identity)
         out, err = capfd.readouterr()
         assert "This is a test function." in out
+
+
+def test_cli_help_contains_function_default_values(capfd):
+    @cfn.config()
+    def identity(a=1, b=2):
+        print(a, b)
+
+    with patch('sys.argv', ['script.py', '--help']):
+        cfn.cli(identity)
+        out, err = capfd.readouterr()
+        assert "a: 1" in out
+        assert "b: 2" in out

tests/test_config.py

@@ -913,5 +913,67 @@ def func(x):
         cfn.Config(func, '.return1')
 
 
+def test_config_config_default_values_are_resolved_properly():
+
+    @cfn.config()
+    def return1():
+        return 1
+
+    @cfn.config()
+    def add1(a=return1):
+        return a + 1
+
+    assert add1.instantiate() == 2
+
+
+def test_config_config_multiple_default_values_are_resolved_properly():
+
+    @cfn.config()
+    def returnx(x=1):
+        return x
+
+    return1 = returnx.override(x=1)
+    return2 = returnx.override(x=2)
+
+    @cfn.config()
+    def add1(a, b=return1, c=return2):
+        return f"{a} + {b} + {c}"
+
+    assert add1(a=0) == "0 + 1 + 2"
+
+
+def test_config_default_function_kwargs_are_overriden_by_config_kwargs():
+    @cfn.config()
+    def return1():
+        return 1
+
+    @cfn.config()
+    def return2():
+        return 2
+
+    @cfn.config(a=return1)
+    def add1(a=return2):
+        return a + 1
+
+    assert add1.instantiate() == 2
+
+
+def test_config_args_and_kwargs_kwargs_are_overriden_by_config_kwargs():
+    @cfn.config()
+    def return1():
+        return 1
+
+    @cfn.config()
+    def return2():
+        return 2
+
+    def func(*args, b=return2):
+        return f"{args} + {b}"
+
+    func = cfn.Config(func, 1, 2, b=return1)
+
+    assert func.instantiate() == "(1, 2) + 1"
+
+
 if __name__ == '__main__':
     pytest.main()