Add test + changed how expansion nodes outputs are resolved

execution.py

@@ -309,17 +309,16 @@ async def _async_map_node_over_list(prompt_id, unique_id, obj, input_data_all, f
     return results
 
 
-def merge_result_data(results, obj, is_list_overrides=[]):
+def merge_result_data(results, obj):
     # check which outputs need concatenating
     output = []
     output_is_list = [False] * len(results[0])
     if hasattr(obj, "OUTPUT_IS_LIST"):
         output_is_list = obj.OUTPUT_IS_LIST
-    is_list_override = is_list_overrides[0] if is_list_overrides else output_is_list
 
     # merge node execution results
-    for i, is_list, override in zip(range(len(results[0])), output_is_list, is_list_override):
+    for i, is_list in zip(range(len(results[0])), output_is_list):
-        if is_list or override:
+        if is_list:
             value = []
             for o in results:
                 if isinstance(o[i], ExecutionBlocker):
@@ -420,6 +419,9 @@ async def execute(server, dynprompt, caches, current_item, extra_data, executed,
     inputs = dynprompt.get_node(unique_id)['inputs']
     class_type = dynprompt.get_node(unique_id)['class_type']
     class_def = nodes.NODE_CLASS_MAPPINGS[class_type]
+    output_is_list = [False] * len(class_def.RETURN_TYPES)
+    if hasattr(class_def, "OUTPUT_IS_LIST"):
+        output_is_list = class_def.OUTPUT_IS_LIST
     cached = caches.outputs.get(unique_id)
     if cached is not None:
         if server.client_id is not None:
@@ -450,35 +452,32 @@ async def execute(server, dynprompt, caches, current_item, extra_data, executed,
         elif unique_id in pending_subgraph_results:
             cached_results = pending_subgraph_results[unique_id]
             resolved_outputs = []
-            is_list_overrides = []
             for is_subgraph, result in cached_results:
                 if not is_subgraph:
                     resolved_outputs.append(result)
                 else:
                     resolved_output = []
-                    is_list_override = []
+                    for i, _result in enumerate(result):
-                    for r in result:
+                        if not output_is_list[i]:
-                        if is_link(r):
+                            if is_link(_result):
-                            source_node, source_output = r[0], r[1]
+                                source_node, source_output = _result[0], _result[1]
-                            _class_type = dynprompt.get_node(source_node)['class_type']
+                                node_cached = execution_list.get_cache(source_node, unique_id)
-                            _class_def = nodes.NODE_CLASS_MAPPINGS[_class_type]
+                                if node_cached.outputs[source_output]:
-                            _source_is_list = False
+                                    resolved_output.append(node_cached.outputs[source_output][0])
-                            if hasattr(_class_def, "OUTPUT_IS_LIST"):
-                                _source_is_list = _class_def.OUTPUT_IS_LIST[source_output]
-                            node_cached = execution_list.get_cache(source_node, unique_id)
-                            if _source_is_list:
-                                resolved_output.append(node_cached.outputs[source_output])
-                                is_list_override.append(_source_is_list)
                             else:
-                                for o in node_cached.outputs[source_output]:
+                                resolved_output.append(_result)
-                                    resolved_output.append(o)
-                                    is_list_override.append(_source_is_list)
                         else:
-                            resolved_output.append(r)
+                            _resolved = []
-                            is_list_override.append(False)
+                            for output in _result:
+                                if is_link(output):
+                                    source_node, source_output = output[0], output[1]
+                                    node_cached = execution_list.get_cache(source_node, unique_id)
+                                    _resolved.extend(node_cached.outputs[source_output])
+                                else:
+                                    _resolved.extend(output)
+                            resolved_output.append(_resolved)
                     resolved_outputs.append(tuple(resolved_output))
-                    is_list_overrides.append(tuple(is_list_override))
+            output_data = merge_result_data(resolved_outputs, class_def)
-            output_data = merge_result_data(resolved_outputs, class_def, is_list_overrides)
             output_ui = []
             del pending_subgraph_results[unique_id]
             has_subgraph = False
@@ -590,9 +589,14 @@ async def execute(server, dynprompt, caches, current_item, extra_data, executed,
                         if hasattr(class_def, 'OUTPUT_NODE') and class_def.OUTPUT_NODE == True:
                             new_output_ids.append(node_id)
                     for i in range(len(node_outputs)):
-                        if is_link(node_outputs[i]):
+                        # Consider a returned list if output_is_list on the parent node
-                            from_node_id, from_socket = node_outputs[i][0], node_outputs[i][1]
+                        _node_outputs = node_outputs[i]
-                            new_output_links.append((from_node_id, from_socket))
+                        if not output_is_list[i]:
+                            _node_outputs = [_node_outputs]
+                        for node_output in _node_outputs:
+                            if is_link(node_output):
+                                from_node_id, from_socket = node_output[0], node_output[1]
+                                new_output_links.append((from_node_id, from_socket))
                     cached_outputs.append((True, node_outputs))
             new_node_ids = set(new_node_ids)
             for cache in caches.all:

tests/execution/test_execution.py

@@ -522,6 +522,58 @@ class TestExecution:
         for i in range(3):
             assert numpy.array(images_literal[i]).min() == 255 and numpy.array(images_literal[i]).max() == 255, "All images should be white"
 
+    # Tests functionality of defining OUTPUT_IS_LIST for expanding nodes.
+    def test_output_is_list_expansion_results(self, client: ComfyClient, builder: GraphBuilder):
+        g = builder
+        list_out = g.node("TestListExpansionResult", value1=0.1)
+        output = g.node("SaveImage", images=list_out.out(0))
+        output_constant = g.node("SaveImage", images=list_out.out(1))
+
+        # return list of one image (list of one link)
+        result = client.run(g)
+        images = result.get_images(output)
+        assert len(images) == 1, "Should have 1 image"
+        assert numpy.array(images[0]).min() == 25 and numpy.array(images[0]).max() == 25, "First image should be 0.1"
+        images_constant = result.get_images(output_constant)
+        assert len(images_constant) == 1, "Should have 1 image"
+        assert numpy.array(images_constant[0]).min() == 255 and numpy.array(images_constant[0]).max() == 255, "Image should be white"
+
+        # test return list of two images (list of two links)
+        list_out.set_input("value2", 0.2)
+        result = client.run(g)
+        images = result.get_images(output)
+        assert len(images) == 2, "Should have 2 images"
+        assert numpy.array(images[0]).min() == 25 and numpy.array(images[0]).max() == 25, "First image should be 0.1"
+        assert numpy.array(images[1]).min() == 51 and numpy.array(images[1]).max() == 51, "Second image should be 0.2"
+        images_constant = result.get_images(output_constant)
+        assert len(images_constant) == 1, "Should have 1 image"
+        assert numpy.array(images_constant[0]).min() == 255 and numpy.array(images_constant[0]).max() == 255, "Image should be white"
+
+        # test mixed links and non-link values in returned list
+        list_out.set_input("value3", 0.3)
+        result = client.run(g)
+        images = result.get_images(output)
+        assert len(images) == 3, "Should have 3 images"
+        assert numpy.array(images[0]).min() == 25 and numpy.array(images[0]).max() == 25, "First image should be 0.1"
+        assert numpy.array(images[1]).min() == 51 and numpy.array(images[1]).max() == 51, "Second image should be 0.2"
+        assert numpy.array(images[2]).min() == 76 and numpy.array(images[2]).max() == 76, "Third image should be 0.3"
+        images_constant = result.get_images(output_constant)
+        assert len(images_constant) == 1, "Should have 1 image"
+        assert numpy.array(images_constant[0]).min() == 255 and numpy.array(images_constant[0]).max() == 255, "Image should be white"
+
+        # test returning list of a single link from an list output subnode
+        list_out.set_input("value4", 0.4)
+        result = client.run(g)
+        images = result.get_images(output)
+        assert len(images) == 4, "Should have 4 images"
+        assert numpy.array(images[0]).min() == 25 and numpy.array(images[0]).max() == 25, "First image should be 0.1"
+        assert numpy.array(images[1]).min() == 51 and numpy.array(images[1]).max() == 51, "Second image should be 0.2"
+        assert numpy.array(images[2]).min() == 76 and numpy.array(images[2]).max() == 76, "Third image should be 0.3"
+        assert numpy.array(images[3]).min() == 102 and numpy.array(images[3]).max() == 102, "Fourth image should be 0.4"
+        images_constant = result.get_images(output_constant)
+        assert len(images_constant) == 1, "Should have 1 image"
+        assert numpy.array(images_constant[0]).min() == 255 and numpy.array(images_constant[0]).max() == 255, "Image should be white"
+
     def test_mixed_lazy_results(self, client: ComfyClient, builder: GraphBuilder):
         g = builder
         val_list = g.node("TestMakeListNode", value1=0.0, value2=0.5, value3=1.0)

tests/execution/testing_nodes/testing-pack/specific_tests.py

@@ -338,6 +338,65 @@ class TestMixedExpansionReturns:
                 "expand": g.finalize(),
             }
 
+class TestListExpansionResult:
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {
+            "required": {
+                "value1": ("FLOAT",),
+            },
+            "optional": {
+                "value2": ("FLOAT",),
+                "value3": ("FLOAT",),
+                "value4": ("FLOAT",),
+            },
+        }
+    
+    RETURN_TYPES = ("IMAGE", "IMAGE")
+    FUNCTION = "result_as_list"
+    OUTPUT_IS_LIST = (True, False)
+    
+    CATEGORY = "Testing/Nodes"
+
+    def result_as_list(self, **kwargs):
+        g = GraphBuilder()
+        values = []
+        for i in range(4):
+            key = f"value{i+1}"
+            if key in kwargs:
+                values.append(kwargs[key])
+        white = g.node("StubImage", content="WHITE", height=512, width=512, batch_size=1)
+        if len(values) == 1:
+            image1 = g.node("StubConstantImage", value=values[0], height=512, width=512, batch_size=1)
+            return {
+                "result": ([image1.out(0)], white.out(0)),
+                "expand": g.finalize(),
+            }
+        elif len(values) == 2:
+            image1 = g.node("StubConstantImage", value=values[0], height=512, width=512, batch_size=1)
+            image2 = g.node("StubConstantImage", value=values[1], height=512, width=512, batch_size=1)
+            return {
+                "result": ([image1.out(0), image2.out(0)], white.out(0)),
+                "expand": g.finalize(),
+            }
+        elif len(values) == 3:
+            image1 = g.node("StubConstantImage", value=values[0], height=512, width=512, batch_size=1)
+            image2 = g.node("StubConstantImage", value=values[1], height=512, width=512, batch_size=1)
+            image3 = torch.ones(1, 512, 512, 3) * values[2]
+            return {
+                "result": ([image1.out(0), image2.out(0), image3], white.out(0)),
+                "expand": g.finalize(),
+            }
+        elif len(values) == 4:
+            list_out = g.node("TestMakeListNode")
+            for i, value in enumerate(values):
+                image = g.node("StubConstantImage", value=value, height=512, width=512, batch_size=1)
+                list_out.set_input(f"value{i+1}", image.out(0))
+            return {
+                "result": ([list_out.out(0)], white.out(0)),
+                "expand": g.finalize(),
+            }
+
 class TestSamplingInExpansion:
     @classmethod
     def INPUT_TYPES(cls):
@@ -494,6 +553,7 @@ TEST_NODE_CLASS_MAPPINGS = {
     "TestCustomValidation5": TestCustomValidation5,
     "TestDynamicDependencyCycle": TestDynamicDependencyCycle,
     "TestMixedExpansionReturns": TestMixedExpansionReturns,
+    "TestListExpansionResult": TestListExpansionResult,
     "TestSamplingInExpansion": TestSamplingInExpansion,
     "TestSleep": TestSleep,
     "TestParallelSleep": TestParallelSleep,
@@ -512,6 +572,7 @@ TEST_NODE_DISPLAY_NAME_MAPPINGS = {
     "TestCustomValidation5": "Custom Validation 5",
     "TestDynamicDependencyCycle": "Dynamic Dependency Cycle",
     "TestMixedExpansionReturns": "Mixed Expansion Returns",
+    "TestListExpansionResult": "Output is List Expansion Result",
     "TestSamplingInExpansion": "Sampling In Expansion",
     "TestSleep": "Test Sleep",
     "TestParallelSleep": "Test Parallel Sleep",