refactor(groupNode): improve type safety and reduce casts

Amp-Thread-ID: https://ampcode.com/threads/T-019baa1c-6aa2-769b-a5f9-a705b5ef2b2b
Co-authored-by: Amp <amp@ampcode.com>

src/extensions/core/groupNode.ts

@@ -4,10 +4,11 @@ import type { GroupNodeWorkflowData } from '@/lib/litegraph/src/LGraph'
 import type {
   GroupNodeInputConfig,
   GroupNodeInputsSpec,
+  GroupNodeInternalLink,
   GroupNodeOutputType,
   PartialLinkInfo
 } from './groupNodeTypes'
-import { LLink, type SerialisedLLinkArray } from '@/lib/litegraph/src/LLink'
+import { LLink } from '@/lib/litegraph/src/LLink'
 import type { NodeId } from '@/lib/litegraph/src/LGraphNode'
 import type { IContextMenuValue } from '@/lib/litegraph/src/interfaces'
 import {
@@ -39,7 +40,7 @@ import { app } from '../../scripts/app'
 import { ManageGroupDialog } from './groupNodeManage'
 import { mergeIfValid } from './widgetInputs'
 
-type GroupNodeLink = SerialisedLLinkArray
+type GroupNodeLink = GroupNodeInternalLink
 type LinksFromMap = Record<number, Record<number, GroupNodeLink[]>>
 type LinksToMap = Record<number, Record<number, GroupNodeLink>>
 type ExternalFromMap = Record<number, Record<number, string | number>>
@@ -1005,7 +1006,7 @@ export class GroupNodeHandler {
           return inputNode
         }
 
-        innerNode.getInputLink = ((slot: number): PartialLinkInfo | null => {
+        innerNode.getInputLink = (slot: number): PartialLinkInfo | null => {
           const nodeIdx = innerNode.index ?? 0
           const externalSlot = this.groupData.oldToNewInputMap[nodeIdx]?.[slot]
           if (externalSlot != null) {
@@ -1025,14 +1026,15 @@ export class GroupNodeHandler {
           const innerLink = this.groupData.linksTo[nodeIdx]?.[slot]
           if (!innerLink) return null
           const linkSrcIdx = innerLink[0]
-          if (linkSrcIdx == null) return null
+          const linkSrcSlot = innerLink[1]
+          if (linkSrcIdx == null || linkSrcSlot == null) return null
           return {
             origin_id: innerNodes[Number(linkSrcIdx)].id,
-            origin_slot: innerLink[1],
+            origin_slot: linkSrcSlot,
             target_id: innerNode.id,
             target_slot: +slot
           }
-        }) as typeof innerNode.getInputLink
+        }
       }
     }
 
@@ -1042,7 +1044,7 @@ export class GroupNodeHandler {
       if (!output || !this.innerNodes) return null
       const nodeIdx = output.node.index ?? 0
       let innerNode: LGraphNode | null = this.innerNodes[nodeIdx]
-      let l
+      let l = innerNode?.getInputLink(0)
       while (innerNode?.type === 'Reroute') {
         l = innerNode.getInputLink(0)
         innerNode = innerNode.getInputNode(0)
@@ -1053,7 +1055,7 @@ export class GroupNodeHandler {
       }
 
       if (
-        l &&
+        l instanceof LLink &&
         GroupNodeHandler.isGroupNode(innerNode) &&
         innerNode.updateLink
       ) {
@@ -1098,10 +1100,9 @@ export class GroupNodeHandler {
 
       const subgraphInstanceIdPath = [...subgraphNodePath, this.node.id]
 
-      // Assertion: Deprecated, does not matter.
-      const subgraphNode = (this.node.graph?.getNodeById(
-        subgraphNodePath.at(-1)
-      ) ?? undefined) as SubgraphNode | undefined
+      // Get the parent subgraph node if we're inside a subgraph
+      const parentNode = this.node.graph?.getNodeById(subgraphNodePath.at(-1))
+      const subgraphNode = parentNode?.isSubgraphNode() ? parentNode : undefined
 
       for (const node of this.innerNodes ?? []) {
         node.graph ??= this.node.graph
@@ -1437,13 +1438,9 @@ export class GroupNodeHandler {
 
     type EventDetail = { display_node?: string; node?: string } | string
     const handleEvent = (
-      type: string,
+      type: 'executing' | 'executed',
       getId: (detail: EventDetail) => string | undefined,
-      getEvent: (
-        detail: EventDetail,
-        id: string,
-        node: LGraphNode
-      ) => EventDetail
+      getEvent: (detail: EventDetail, id: string, node: LGraphNode) => unknown
     ) => {
       const handler = ({ detail }: CustomEvent<EventDetail>) => {
         const id = getId(detail)
@@ -1457,16 +1454,14 @@ export class GroupNodeHandler {
           ;(
             this.node as LGraphNode & { runningInternalNodeId?: number }
           ).runningInternalNodeId = innerNodeIndex
+          // Cast needed: dispatching synthetic events for inner nodes with transformed payloads
           api.dispatchCustomEvent(
-            type as 'executing',
+            type,
             getEvent(detail, `${this.node.id}`, this.node) as string
           )
         }
       }
-      api.addEventListener(
-        type as 'executing' | 'executed',
-        handler as EventListener
-      )
+      api.addEventListener(type, handler as EventListener)
       return handler
     }
 

src/extensions/core/groupNodeTypes.ts

@@ -1,6 +1,21 @@
-import type { SerialisedLLinkArray } from '@/lib/litegraph/src/LLink'
+import type { ILinkRouting } from '@/lib/litegraph/src/interfaces'
+import type { ISlotType } from '@/lib/litegraph/src/interfaces'
 import type { ISerialisedNode } from '@/lib/litegraph/src/types/serialisation'
 
+/**
+ * Group node internal link format.
+ * This differs from standard SerialisedLLinkArray - indices represent node/slot positions within the group.
+ * Format: [sourceNodeIndex, sourceSlot, targetNodeIndex, targetSlot, ...optionalData]
+ * The type (ISlotType) may be at index 5 if present.
+ */
+export type GroupNodeInternalLink = [
+  sourceNodeIndex: number | null,
+  sourceSlot: number | null,
+  targetNodeIndex: number | null,
+  targetSlot: number | null,
+  ...rest: (number | string | ISlotType | null | undefined)[]
+]
+
 /** Serialized node data within a group node workflow, with group-specific index */
 export interface GroupNodeSerializedNode extends Partial<ISerialisedNode> {
   /** Position of this node within the group */
@@ -9,7 +24,7 @@ export interface GroupNodeSerializedNode extends Partial<ISerialisedNode> {
 
 export interface GroupNodeWorkflowData {
   external: (number | string)[][]
-  links: SerialisedLLinkArray[]
+  links: GroupNodeInternalLink[]
   nodes: GroupNodeSerializedNode[]
   config?: Record<number, unknown>
 }
@@ -37,11 +52,6 @@ export type GroupNodeOutputType = string | (string | number)[]
 
 /**
  * Partial link info used internally by group node getInputLink override.
- * Contains only the properties needed for group node execution context.
+ * Extends ILinkRouting to be compatible with the base getInputLink return type.
  */
-export interface PartialLinkInfo {
-  origin_id: string | number
-  origin_slot: number | string
-  target_id: string | number
-  target_slot: number
-}
+export interface PartialLinkInfo extends ILinkRouting {}

src/lib/litegraph/src/LGraphNode.ts

@@ -34,6 +34,7 @@ import type {
   IColorable,
   IContextMenuValue,
   IFoundSlot,
+  ILinkRouting,
   INodeFlags,
   INodeInputSlot,
   INodeOutputSlot,
@@ -1153,10 +1154,11 @@ export class LGraphNode
   }
 
   /**
-   * Returns the link info in the connection of an input slot
-   * @returns object or null
+   * Returns the link info in the connection of an input slot.
+   * Group nodes may override this to return ILinkRouting for internal routing.
+   * @returns LLink, ILinkRouting, or null
    */
-  getInputLink(slot: number): LLink | null {
+  getInputLink(slot: number): LLink | ILinkRouting | null {
     if (!this.inputs) return null
 
     if (slot < this.inputs.length) {

src/lib/litegraph/src/LLink.ts

@@ -11,6 +11,7 @@ import type { LGraphNode, NodeId } from './LGraphNode'
 import type { Reroute, RerouteId } from './Reroute'
 import type {
   CanvasColour,
+  ILinkRouting,
   INodeInputSlot,
   INodeOutputSlot,
   ISlotType,
@@ -89,7 +90,9 @@ type BasicReadonlyNetwork = Pick<
 >
 
 // this is the class in charge of storing link information
-export class LLink implements LinkSegment, Serialisable<SerialisableLLink> {
+export class LLink
+  implements LinkSegment, Serialisable<SerialisableLLink>, ILinkRouting
+{
   static _drawDebug = false
 
   /** Link ID */

src/lib/litegraph/src/interfaces.ts

@@ -184,6 +184,21 @@ export interface ItemLocator {
   ): SubgraphInputNode | SubgraphOutputNode | undefined
 }
 
+/**
+ * Minimal link routing information used for input resolution.
+ * Both LLink and partial link info objects satisfy this interface.
+ */
+export interface ILinkRouting {
+  /** Output node ID */
+  readonly origin_id: NodeId
+  /** Output slot index */
+  readonly origin_slot: number
+  /** Input node ID */
+  readonly target_id: NodeId
+  /** Input slot index */
+  readonly target_slot: number
+}
+
 /** Contains a cached 2D canvas path and a centre point, with an optional forward angle. */
 export interface LinkSegment {
   /** Link / reroute ID */

src/lib/litegraph/src/subgraph/ExecutableNodeDTO.ts

@@ -9,7 +9,11 @@ import type {
   CallbackReturn,
   ISlotType
 } from '@/lib/litegraph/src/interfaces'
-import { LGraphEventMode, LiteGraph } from '@/lib/litegraph/src/litegraph'
+import {
+  LGraphEventMode,
+  LiteGraph,
+  LLink
+} from '@/lib/litegraph/src/litegraph'
 
 import type { Subgraph } from './Subgraph'
 import type { SubgraphNode } from './SubgraphNode'
@@ -289,7 +293,7 @@ export class ExecutableNodeDTO implements ExecutableLGraphNode {
 
     if (node.isVirtualNode) {
       const virtualLink = this.node.getInputLink(slot)
-      if (virtualLink) {
+      if (virtualLink instanceof LLink) {
         const { inputNode } = virtualLink.resolve(this.graph)
         if (!inputNode)
           throw new InvalidLinkError(