combine fft filter into a single node, fix tests

backend/node_registry.py

@@ -15,28 +15,38 @@ NODE_CLASS_MAPPINGS: dict[str, type] = {}
 NODE_DISPLAY_NAME_MAPPINGS: dict[str, str] = {}
 
 
-def get_node_output_specs(cls: type) -> tuple[tuple[str, str], ...]:
+def get_node_output_specs(cls: type) -> tuple[tuple[str, str, dict], ...]:
     raw_outputs = getattr(cls, "OUTPUTS", None)
     if raw_outputs is None:
         raise AttributeError(f"{cls.__name__} must define OUTPUTS.")
 
-    specs: list[tuple[str, str]] = []
+    specs: list[tuple[str, str, dict]] = []
     for index, output in enumerate(raw_outputs):
-        if not isinstance(output, (list, tuple)) or len(output) != 2:
+        if not isinstance(output, (list, tuple)) or len(output) not in (2, 3):
             raise TypeError(
-                f"{cls.__name__}.OUTPUTS[{index}] must be a 2-item tuple of (type, name)."
+                f"{cls.__name__}.OUTPUTS[{index}] must be a 2- or 3-item tuple of (type, name[, meta])."
             )
-        type_name, name = output
-        specs.append((str(type_name), str(name)))
+        type_name = output[0]
+        name = output[1]
+        meta: dict = output[2] if len(output) == 3 else {}
+        specs.append((str(type_name), str(name), meta))
     return tuple(specs)
 
 
 def get_node_output_types(cls: type) -> tuple[str, ...]:
-    return tuple(type_name for type_name, _ in get_node_output_specs(cls))
+    return tuple(type_name for type_name, _, _meta in get_node_output_specs(cls))
 
 
 def get_node_output_names(cls: type) -> tuple[str, ...]:
-    return tuple(name for _, name in get_node_output_specs(cls))
+    return tuple(name for _, name, _meta in get_node_output_specs(cls))
+
+
+def get_node_output_accepted_types(cls: type) -> tuple[list[str], ...]:
+    """Return per-slot accepted_types lists (empty list means only the declared type)."""
+    return tuple(
+        list(meta.get("accepted_types", []))
+        for _, _, meta in get_node_output_specs(cls)
+    )
 
 
 def register_node(display_name: str | None = None):
@@ -77,6 +87,7 @@ def get_node_info(class_name: str) -> dict[str, Any]:
         "input_order": {k: list(v.keys()) for k, v in input_types.items()},
         "output": list(get_node_output_types(cls)),
         "output_name": list(get_node_output_names(cls)),
+        "output_accepted_types": list(get_node_output_accepted_types(cls)),
         "output_node": bool(getattr(cls, "OUTPUT_NODE", False)),
         "manual_trigger": bool(getattr(cls, "MANUAL_TRIGGER", False)),
         "description": getattr(cls, "DESCRIPTION", ""),