refactor(core): allow passing null/undefined to use node connection args (#1820)

* refactor(core): allow passing null/undefined to use node connection args

Signed-off-by: braks <78412429+bcakmakoglu@users.noreply.github.com>

* chore(core): cleanup

Signed-off-by: braks <78412429+bcakmakoglu@users.noreply.github.com>

* chore(changeset): add

---------

Signed-off-by: braks <78412429+bcakmakoglu@users.noreply.github.com>

.changeset/shiny-pots-wash.md

@@ -0,0 +1,5 @@
+---
+"@vue-flow/core": minor
+---
+
+Allow passing null or undefined to `useNodeConnections` options

packages/core/src/composables/useNodeConnections.ts

@@ -6,9 +6,9 @@ import { useNodeId } from './useNodeId'
 import { useVueFlow } from './useVueFlow'
 
 export interface UseNodeConnectionsParams {
-  handleType?: MaybeRefOrGetter<HandleType>
-  handleId?: MaybeRefOrGetter<string | null>
-  nodeId?: MaybeRefOrGetter<string | null>
+  handleType?: MaybeRefOrGetter<HandleType | null | undefined>
+  handleId?: MaybeRefOrGetter<string | null | undefined>
+  nodeId?: MaybeRefOrGetter<string | null | undefined>
   onConnect?: (connections: NodeConnection[]) => void
   onDisconnect?: (connections: NodeConnection[]) => void
 }
@@ -42,9 +42,12 @@ export function useNodeConnections(params: UseNodeConnectionsParams = {}) {
     const currentHandleType = toValue(handleType)
     const currHandleId = toValue(handleId)
 
-    return `${currNodeId}${
-      currentHandleType ? (currHandleId ? `-${currentHandleType}-${currHandleId}` : `-${currentHandleType}`) : ''
-    }`
+    let handleSuffix = ''
+    if (currentHandleType) {
+      handleSuffix = currHandleId ? `-${currentHandleType}-${currHandleId}` : `-${currentHandleType}`
+    }
+
+    return `${currNodeId}${handleSuffix}`
   })
 
   watch(