fix: preserve falsy primitive args in Config/Partial binding

nemo_run/config.py

@@ -577,7 +577,7 @@ def _construct_args(
     for name, parameter in params.items():
         arg = kwargs.get(name, None)
 
-        if arg:
+        if arg is not None:
             if dataclasses.is_dataclass(arg):
                 final_args[name] = fdl.cast(
                     Config,

test/test_config.py

@@ -66,6 +66,10 @@ def train_manual(
     return optim
 
 
+def with_falsy_values(count: int = 1, flag: bool = True, label: str = "x"):
+    return count, flag, label
+
+
 @dataclass
 class Data:
     name: str
@@ -222,6 +226,13 @@ def test_default_optional(self, train_func):
 
         assert fn() == fdl.build(optimizer())
 
+    def test_falsy_primitive_args_are_preserved(self):
+        """Falsy primitive values like 0, False, and '' must not be dropped."""
+        partial = run.Partial(with_falsy_values, count=0, flag=False, label="")
+        fn = fdl.build(partial)
+
+        assert fn() == (0, False, "")
+
     def test_clone(self):
         partial = run.Partial(train, model=dummy_model(), optim=optimizer())
         clone = partial.clone()