#975 Application hangs after undo action applying to S-Group type cha…

…nges (#978)

update priority of s-group hierarchy operations
# Conflicts:
#	packages/ketcher-core/src/domain/entities/sgroupForest.ts

packages/ketcher-core/src/application/editor/operations/sgroup/sgroupHierarchy.ts

@@ -30,7 +30,7 @@ class SGroupAddToHierarchy extends BaseOperation {
   data: Data
 
   constructor(sgroupId?: any, parent?: any, children?: any) {
-    super(OperationType.S_GROUP_ADD_TO_HIERACHY, 4)
+    super(OperationType.S_GROUP_ADD_TO_HIERACHY, 100)
     this.data = { sgid: sgroupId, parent, children }
   }
 
@@ -56,7 +56,7 @@ class SGroupRemoveFromHierarchy extends BaseOperation {
   data: Data
 
   constructor(sgroupId?: any) {
-    super(OperationType.S_GROUP_REMOVE_FROM_HIERACHY)
+    super(OperationType.S_GROUP_REMOVE_FROM_HIERACHY, 110)
     this.data = { sgid: sgroupId }
   }
 

packages/ketcher-core/src/domain/entities/sgroupForest.ts

@@ -36,14 +36,24 @@ export class SGroupForest {
   /** returns an array or s-group ids in the order of breadth-first search */
   getSGroupsBFS(): number[] {
     const order: number[] = []
-    let id = -1
-    let queue = Array.from(this.children.get(-1) as any)
+    const queue = Array.from(this.children.get(-1) as Array<number>)
     while (queue.length > 0) {
-      id = queue.shift() as any
+      const id = queue.shift()
+      if (typeof id !== 'number') {
+        break
+      }
       const children = this.children.get(id)
-      queue = queue.concat(children as any)
+      if (typeof children === 'undefined') {
+        break
+      }
+
+      children.forEach(id => {
+        queue.push(id)
+      })
+
       order.push(id)
     }
+
     return order
   }