feat: add lora stack combiner node

__init__.py

@@ -7,6 +7,7 @@ try:  # pragma: no cover - import fallback for pytest collection
     from .py.nodes.prompt import PromptLM
     from .py.nodes.text import TextLM
     from .py.nodes.lora_stacker import LoraStackerLM
+    from .py.nodes.lora_stack_combiner import LoraStackCombinerLM
     from .py.nodes.save_image import SaveImageLM
     from .py.nodes.debug_metadata import DebugMetadataLM
     from .py.nodes.wanvideo_lora_select import WanVideoLoraSelectLM
@@ -39,6 +40,9 @@ except (
         "py.nodes.trigger_word_toggle"
     ).TriggerWordToggleLM
     LoraStackerLM = importlib.import_module("py.nodes.lora_stacker").LoraStackerLM
+    LoraStackCombinerLM = importlib.import_module(
+        "py.nodes.lora_stack_combiner"
+    ).LoraStackCombinerLM
     SaveImageLM = importlib.import_module("py.nodes.save_image").SaveImageLM
     DebugMetadataLM = importlib.import_module("py.nodes.debug_metadata").DebugMetadataLM
     WanVideoLoraSelectLM = importlib.import_module(
@@ -63,6 +67,7 @@ NODE_CLASS_MAPPINGS = {
     UNETLoaderLM.NAME: UNETLoaderLM,
     TriggerWordToggleLM.NAME: TriggerWordToggleLM,
     LoraStackerLM.NAME: LoraStackerLM,
+    LoraStackCombinerLM.NAME: LoraStackCombinerLM,
     SaveImageLM.NAME: SaveImageLM,
     DebugMetadataLM.NAME: DebugMetadataLM,
     WanVideoLoraSelectLM.NAME: WanVideoLoraSelectLM,

py/nodes/lora_stack_combiner.py

@@ -0,0 +1,26 @@
+class LoraStackCombinerLM:
+    NAME = "Lora Stack Combiner (LoraManager)"
+    CATEGORY = "Lora Manager/stackers"
+
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {
+            "required": {
+                "lora_stack_a": ("LORA_STACK",),
+                "lora_stack_b": ("LORA_STACK",),
+            },
+        }
+
+    RETURN_TYPES = ("LORA_STACK",)
+    RETURN_NAMES = ("LORA_STACK",)
+    FUNCTION = "combine_stacks"
+
+    def combine_stacks(self, lora_stack_a, lora_stack_b):
+        combined_stack = []
+
+        if lora_stack_a:
+            combined_stack.extend(lora_stack_a)
+        if lora_stack_b:
+            combined_stack.extend(lora_stack_b)
+
+        return (combined_stack,)

tests/nodes/test_lora_stack_combiner.py

@@ -0,0 +1,51 @@
+from py.nodes.lora_stack_combiner import LoraStackCombinerLM
+
+
+def test_combine_stacks_preserves_order():
+    node = LoraStackCombinerLM()
+    stack_a = [
+        ("folder/a.safetensors", 0.7, 0.6),
+        ("folder/b.safetensors", 0.8, 0.8),
+    ]
+    stack_b = [
+        ("folder/c.safetensors", 1.0, 0.9),
+    ]
+
+    (combined_stack,) = node.combine_stacks(stack_a, stack_b)
+
+    assert combined_stack == stack_a + stack_b
+
+
+def test_combine_stacks_returns_second_when_first_empty():
+    node = LoraStackCombinerLM()
+    stack_b = [("folder/c.safetensors", 1.0, 0.9)]
+
+    (combined_stack,) = node.combine_stacks([], stack_b)
+
+    assert combined_stack == stack_b
+
+
+def test_combine_stacks_returns_first_when_second_empty():
+    node = LoraStackCombinerLM()
+    stack_a = [("folder/a.safetensors", 0.7, 0.6)]
+
+    (combined_stack,) = node.combine_stacks(stack_a, [])
+
+    assert combined_stack == stack_a
+
+
+def test_combine_stacks_returns_empty_when_both_empty():
+    node = LoraStackCombinerLM()
+
+    (combined_stack,) = node.combine_stacks([], [])
+
+    assert combined_stack == []
+
+
+def test_combine_stacks_allows_duplicate_entries():
+    node = LoraStackCombinerLM()
+    duplicate_entry = ("folder/shared.safetensors", 0.9, 0.5)
+
+    (combined_stack,) = node.combine_stacks([duplicate_entry], [duplicate_entry])
+
+    assert combined_stack == [duplicate_entry, duplicate_entry]