NaN-safe JSON serialization

json.dumps() will produce nonstandard JSON if there are NaNs in the data.
Javascript's JSON.parse() will refuse to load this kind of "JSON".

At least the is_changed key can be NaN or something else if a node returns NaNs
from its IS_CHANGED function.

Fortunately, json.loads() allows parsing NaN's into Nones, so round-tripping
once is a pretty easy fix.

comfy/utils.py

@@ -6,6 +6,14 @@ import safetensors.torch
 import numpy as np
 from PIL import Image
 import logging
+import json
+
+
+def dump_json(data):
+    # Roundtrip once to get rid of NaN, Infinity and -Infinity
+    good_data = json.loads(json.dumps(data), parse_constant=lambda x: None)
+    return json.dumps(good_data, allow_nan=False)
+
 
 def load_torch_file(ckpt, safe_load=False, device=None):
     if device is None:

comfy_extras/nodes_images.py

@@ -1,12 +1,12 @@
 import nodes
 import folder_paths
 from comfy.cli_args import args
+import comfy.utils
 
 from PIL import Image
 from PIL.PngImagePlugin import PngInfo
 
 import numpy as np
-import json
 import os
 
 MAX_RESOLUTION = nodes.MAX_RESOLUTION
@@ -109,11 +109,11 @@ class SaveAnimatedWEBP:
         metadata = pil_images[0].getexif()
         if not args.disable_metadata:
             if prompt is not None:
-                metadata[0x0110] = "prompt:{}".format(json.dumps(prompt))
+                metadata[0x0110] = "prompt:{}".format(comfy.utils.dump_json(prompt))
             if extra_pnginfo is not None:
                 inital_exif = 0x010f
                 for x in extra_pnginfo:
-                    metadata[inital_exif] = "{}:{}".format(x, json.dumps(extra_pnginfo[x]))
+                    metadata[inital_exif] = "{}:{}".format(x, comfy.utils.dump_json(extra_pnginfo[x]))
                     inital_exif -= 1
 
         if num_frames == 0:
@@ -171,10 +171,10 @@ class SaveAnimatedPNG:
         if not args.disable_metadata:
             metadata = PngInfo()
             if prompt is not None:
-                metadata.add(b"comf", "prompt".encode("latin-1", "strict") + b"\0" + json.dumps(prompt).encode("latin-1", "strict"), after_idat=True)
+                metadata.add(b"comf", "prompt".encode("latin-1", "strict") + b"\0" + comfy.utils.dump_json(prompt).encode("latin-1", "strict"), after_idat=True)
             if extra_pnginfo is not None:
                 for x in extra_pnginfo:
-                    metadata.add(b"comf", x.encode("latin-1", "strict") + b"\0" + json.dumps(extra_pnginfo[x]).encode("latin-1", "strict"), after_idat=True)
+                    metadata.add(b"comf", x.encode("latin-1", "strict") + b"\0" + comfy.utils.dump_json(extra_pnginfo[x]).encode("latin-1", "strict"), after_idat=True)
 
         file = f"{filename}_{counter:05}_.png"
         pil_images[0].save(os.path.join(full_output_folder, file), pnginfo=metadata, compress_level=compress_level, save_all=True, duration=int(1000.0/fps), append_images=pil_images[1:])

comfy_extras/nodes_model_merging.py

@@ -4,7 +4,6 @@ import comfy.model_base
 import comfy.model_management
 
 import folder_paths
-import json
 import os
 
 from comfy.cli_args import args
@@ -167,7 +166,7 @@ def save_checkpoint(model, clip=None, vae=None, clip_vision=None, filename_prefi
     full_output_folder, filename, counter, subfolder, filename_prefix = folder_paths.get_save_image_path(filename_prefix, output_dir)
     prompt_info = ""
     if prompt is not None:
-        prompt_info = json.dumps(prompt)
+        prompt_info = comfy.utils.dump_json(prompt)
 
     metadata = {}
 
@@ -198,7 +197,7 @@ def save_checkpoint(model, clip=None, vae=None, clip_vision=None, filename_prefi
         metadata["prompt"] = prompt_info
         if extra_pnginfo is not None:
             for x in extra_pnginfo:
-                metadata[x] = json.dumps(extra_pnginfo[x])
+                metadata[x] = comfy.utils.dump_json(extra_pnginfo[x])
 
     output_checkpoint = f"{filename}_{counter:05}_.safetensors"
     output_checkpoint = os.path.join(full_output_folder, output_checkpoint)
@@ -244,14 +243,14 @@ class CLIPSave:
     def save(self, clip, filename_prefix, prompt=None, extra_pnginfo=None):
         prompt_info = ""
         if prompt is not None:
-            prompt_info = json.dumps(prompt)
+            prompt_info = comfy.utils.dump_json(prompt)
 
         metadata = {}
         if not args.disable_metadata:
             metadata["prompt"] = prompt_info
             if extra_pnginfo is not None:
                 for x in extra_pnginfo:
-                    metadata[x] = json.dumps(extra_pnginfo[x])
+                    metadata[x] = comfy.utils.dump_json(extra_pnginfo[x])
 
         comfy.model_management.load_models_gpu([clip.load_model()])
         clip_sd = clip.get_sd()
@@ -301,14 +300,14 @@ class VAESave:
         full_output_folder, filename, counter, subfolder, filename_prefix = folder_paths.get_save_image_path(filename_prefix, self.output_dir)
         prompt_info = ""
         if prompt is not None:
-            prompt_info = json.dumps(prompt)
+            prompt_info = comfy.utils.dump_json(prompt)
 
         metadata = {}
         if not args.disable_metadata:
             metadata["prompt"] = prompt_info
             if extra_pnginfo is not None:
                 for x in extra_pnginfo:
-                    metadata[x] = json.dumps(extra_pnginfo[x])
+                    metadata[x] = comfy.utils.dump_json(extra_pnginfo[x])
 
         output_checkpoint = f"{filename}_{counter:05}_.safetensors"
         output_checkpoint = os.path.join(full_output_folder, output_checkpoint)

nodes.py

@@ -2,7 +2,6 @@ import torch
 
 import os
 import sys
-import json
 import hashlib
 import traceback
 import math
@@ -447,14 +446,14 @@ class SaveLatent:
         # support save metadata for latent sharing
         prompt_info = ""
         if prompt is not None:
-            prompt_info = json.dumps(prompt)
+            prompt_info = comfy.utils.dump_json(prompt)
 
         metadata = None
         if not args.disable_metadata:
             metadata = {"prompt": prompt_info}
             if extra_pnginfo is not None:
                 for x in extra_pnginfo:
-                    metadata[x] = json.dumps(extra_pnginfo[x])
+                    metadata[x] = comfy.utils.dump_json(extra_pnginfo[x])
 
         file = f"{filename}_{counter:05}_.latent"
 
@@ -1435,10 +1434,10 @@ class SaveImage:
             if not args.disable_metadata:
                 metadata = PngInfo()
                 if prompt is not None:
-                    metadata.add_text("prompt", json.dumps(prompt))
+                    metadata.add_text("prompt", comfy.utils.dump_json(prompt))
                 if extra_pnginfo is not None:
                     for x in extra_pnginfo:
-                        metadata.add_text(x, json.dumps(extra_pnginfo[x]))
+                        metadata.add_text(x, comfy.utils.dump_json(extra_pnginfo[x]))
 
             filename_with_batch_num = filename.replace("%batch_num%", str(batch_number))
             file = f"{filename_with_batch_num}_{counter:05}_.png"