serialize inf as strings

pylabrobot/gui/welcome.js

@@ -73,7 +73,11 @@ window.addEventListener("load", () => {
       const reader = new FileReader();
 
       reader.onload = (e) => {
-        const deck = JSON.parse(e.target.result);
+        const deck = JSON.parse(e.target.result, (key, value) => {
+          if (value == "Infinity") return Infinity;
+          if (value == "-Infinity") return -Infinity;
+          return value;
+        });
         fileContents = deck;
 
         // TODO: validate deck on the server

pylabrobot/resources/container.py

@@ -57,7 +57,7 @@ def material_z_thickness(self) -> float:
   def serialize(self) -> dict:
     return {
       **super().serialize(),
-      "max_volume": self.max_volume,
+      "max_volume": serialize(self.max_volume),
       "material_z_thickness": self._material_z_thickness,
       "compute_volume_from_height": serialize(self._compute_volume_from_height),
       "compute_height_from_volume": serialize(self._compute_height_from_volume),

pylabrobot/serializer.py

@@ -3,6 +3,7 @@
 import enum
 import inspect
 import marshal
+import math
 import sys
 import types
 from typing import Any, Dict, List, Union, cast
@@ -29,6 +30,9 @@ def serialize(obj: Any) -> JSON:
   """Serialize an object."""
 
   if isinstance(obj, (int, float, str, bool, type(None))):
+    # infinities and NaNs are not valid JSON, so we convert them to strings
+    if isinstance(obj, float) and not math.isfinite(obj):
+      return "nan" if math.isnan(obj) else ("Infinity" if obj > 0 else "-Infinity")
     return obj
   if isinstance(obj, (list, tuple, set)):
     return [serialize(item) for item in obj]

pylabrobot/visualizer/vis.js

@@ -151,7 +151,11 @@ function openSocket() {
   // webSocket.onmessage = function (event) {
   webSocket.addEventListener("message", function (event) {
     var data = event.data;
-    data = JSON.parse(data);
+    data = JSON.parse(data, (key, value) => {
+      if (value == "Infinity") return Infinity;
+      if (value == "-Infinity") return -Infinity;
+      return value;
+    });
     console.log(`[message] Data received from server:`, data);
     handleEvent(data.id, data.event, data.data);
   });