serialize to string at proxyWidgets boundry

While node.properties function with anything serializeable, the format
for proxyWidgets is not a valid option for type. After great
consideration, all access to and from this value goes through a JSON
serialization and parsing always includes a zod validation step.

This is sturdier to outside misuse, has even lower risk of custom node
breakage, and means that there's now proper type checking at the
boundries of interaction.

Performance was a major concern against this, but the path is quite
cold. I estimate the value of optimization here to be 3-4 orders of
magnitude less important than anything occuring during the draw loop
(like access to proxyWidget elements)

src/extensions/core/proxyWidget.ts

@@ -1,3 +1,7 @@
+import { z } from 'zod'
+import { fromZodError } from 'zod-validation-error'
+
+import type { NodeProperty } from '@/lib/litegraph/src/LGraphNode'
 import type { LGraph, LGraphNode } from '@/lib/litegraph/src/litegraph'
 import { SubgraphNode } from '@/lib/litegraph/src/subgraph/SubgraphNode'
 import type { IBaseWidget } from '@/lib/litegraph/src/types/widgets.ts'
@@ -5,6 +9,31 @@ import { disconnectedWidget } from '@/lib/litegraph/src/widgets/DisconnectedWidg
 import { DOMWidgetImpl } from '@/scripts/domWidget'
 import { useExtensionService } from '@/services/extensionService'
 import { useDomWidgetStore } from '@/stores/domWidgetStore'
+import { useCanvasStore } from '@/stores/graphStore'
+
+const canvasStore = useCanvasStore()
+
+export const proxyWidgetsPropertySchema = z.array(
+  z.tuple([z.string(), z.string()])
+)
+export type ProxyWidgetsProperty = z.infer<typeof proxyWidgetsPropertySchema>
+//export type proxyWidgetsProperty = [string, string][]
+
+export function parseProxyWidgets(
+  property: NodeProperty | undefined
+): ProxyWidgetsProperty {
+  if (typeof property !== 'string') {
+    console.error(`Found non-string value for properties.proxyWidgets`)
+    return []
+  }
+  const parsed = JSON.parse(property)
+  const result = proxyWidgetsPropertySchema.safeParse(parsed)
+  if (result.success) return result.data ?? []
+
+  const error = fromZodError(result.error)
+  console.error(`Invalid assignment for properties.proxyWidgets:\n${error}`)
+  return []
+}
 
 useExtensionService().registerExtension({
   name: 'Comfy.SubgraphProxyWidgets',
@@ -19,11 +48,13 @@ function injectProperty(subgraphNode: SubgraphNode) {
   const proxyWidgets = subgraphNode.properties.proxyWidgets
   Object.defineProperty(subgraphNode.properties, 'proxyWidgets', {
     get: () => {
-      return subgraphNode.widgets
+      const result = subgraphNode.widgets
         .filter((w) => isProxyWidget(w))
         .map((w) => [w._overlay.nodeId, w._overlay.widgetName])
+      return JSON.stringify(result)
     },
-    set: (property) => {
+    set: (property: string) => {
+      const parsed = parseProxyWidgets(property)
       const { widgetStates } = useDomWidgetStore()
       for (const w of subgraphNode.widgets ?? []) {
         if (w instanceof DOMWidgetImpl && widgetStates.has(w.id)) {
@@ -36,7 +67,7 @@ function injectProperty(subgraphNode: SubgraphNode) {
       subgraphNode.widgets = subgraphNode.widgets.filter(
         (w) => !isProxyWidget(w)
       )
-      for (const [nodeId, widgetName] of property) {
+      for (const [nodeId, widgetName] of parsed) {
         const w = addProxyWidget(subgraphNode, `${nodeId}`, widgetName)
         if (w instanceof DOMWidgetImpl) {
           const widgetState = widgetStates.get(w.id)
@@ -45,7 +76,7 @@ function injectProperty(subgraphNode: SubgraphNode) {
           widgetState.widget = w
         }
       }
-      //TODO: set dirty canvas
+      canvasStore.canvas?.setDirty(true, true)
     }
   })
   subgraphNode.properties.proxyWidgets = proxyWidgets