fix(nodes): make Lora Stack Combiner inputs optional

py/nodes/lora_stack_combiner.py

@@ -5,7 +5,8 @@ class LoraStackCombinerLM:
     @classmethod
     def INPUT_TYPES(cls):
         return {
-            "required": {
+            "required": {},
+            "optional": {
                 "lora_stack_a": ("LORA_STACK",),
                 "lora_stack_b": ("LORA_STACK",),
             },
@@ -15,7 +16,7 @@ class LoraStackCombinerLM:
     RETURN_NAMES = ("LORA_STACK",)
     FUNCTION = "combine_stacks"
 
-    def combine_stacks(self, lora_stack_a, lora_stack_b):
+    def combine_stacks(self, lora_stack_a=None, lora_stack_b=None):
         combined_stack = []
 
         if lora_stack_a:

tests/nodes/test_lora_stack_combiner.py

@@ -49,3 +49,22 @@ def test_combine_stacks_allows_duplicate_entries():
     (combined_stack,) = node.combine_stacks([duplicate_entry], [duplicate_entry])
 
     assert combined_stack == [duplicate_entry, duplicate_entry]
+
+
+def test_combine_stacks_returns_empty_when_both_unconnected():
+    node = LoraStackCombinerLM()
+
+    (combined_stack,) = node.combine_stacks()
+
+    assert combined_stack == []
+
+
+def test_combine_stacks_returns_other_when_one_unconnected():
+    node = LoraStackCombinerLM()
+    stack_a = [("folder/a.safetensors", 0.7, 0.6)]
+
+    (combined_stack_a,) = node.combine_stacks(lora_stack_a=stack_a)
+    (combined_stack_b,) = node.combine_stacks(lora_stack_b=stack_a)
+
+    assert combined_stack_a == stack_a
+    assert combined_stack_b == stack_a