joshmossas
diff --git a/‎__tests__/renderer/ViewNode.test.js
Lines changed: 21 additions & 0 deletions b/‎__tests__/renderer/ViewNode.test.js
Lines changed: 21 additions & 0 deletions
diff --git a/‎platform/nativescript/renderer/ViewNode.js
Lines changed: 12 additions & 16 deletions b/‎platform/nativescript/renderer/ViewNode.js
Lines changed: 12 additions & 16 deletions
@@ -120,6 +120,27 @@ describe('ViewNode', () => {
     expect(refNode.nextSibling).toBeFalsy()
   })
 
+  test('insertBefore sets siblings of both siblings', () => {
+    let parentNode = new ViewNode()
+    let firstNode = new ViewNode()
+    let lastNode = new ViewNode()
+    let childNode = new ViewNode()
+    parentNode.childNodes = [firstNode, lastNode]
+    firstNode.parentNode = parentNode
+    lastNode.parentNode = parentNode
+
+    parentNode.insertBefore(childNode, lastNode)
+
+    expect(parentNode.childNodes.length).toBe(3)
+    expect(childNode.parentNode).toEqual(parentNode)
+    expect(firstNode.nextSibling).toEqual(childNode)
+    expect(lastNode.prevSibling).toEqual(childNode)
+    expect(childNode.prevSibling).toEqual(firstNode)
+    expect(childNode.nextSibling).toEqual(lastNode)
+    expect(firstNode.prevSibling).toBeFalsy()
+    expect(lastNode.nextSibling).toBeFalsy()
+
   test('appendChild throws if no childNode is given', () => {
     let node = new ViewNode()
 
 
@@ -165,13 +165,11 @@ export default class ViewNode {
       throw new Error(`Can't insert child.`)
     }
 
-    // in some rare cases insertBefore is called with a null referenceNode
-    // this makes sure that it get's appended as the last child
-    if (!referenceNode) {
-      return this.appendChild(childNode)
-    }
-
-    if (referenceNode.parentNode && referenceNode.parentNode !== this) {
+    if (
+      referenceNode &&
+      referenceNode.parentNode &&
+      referenceNode.parentNode !== this
+    ) {
       throw new Error(
         `Can't insert child, because the reference node has a different parent.`
       )
@@ -197,11 +195,18 @@ export default class ViewNode {
       // throw new Error(`Can't insert child, because it is already a child.`)
     }
 
+    // in some rare cases insertBefore is called with a null referenceNode
+    // this makes sure that it get's appended as the last child
+    if (!referenceNode) {
+      return this.appendChild(childNode)
+    }
+
     let index = this.childNodes.indexOf(referenceNode)
 
     childNode.parentNode = this
     childNode.nextSibling = referenceNode
     childNode.prevSibling = this.childNodes[index - 1]
+    if (childNode.prevSibling) childNode.prevSibling.nextSibling = childNode
 
     referenceNode.prevSibling = childNode
     this.childNodes.splice(index, 0, childNode)
@@ -220,16 +225,7 @@ export default class ViewNode {
       )
     }
 
-    if (childNode.parentNode === this) {
-      // we don't need to throw an error here, because it is a valid case
-      // for example when switching the order of elements in the tree
-      // fixes #127 - see for more details
-      // fixes #240
-      // throw new Error(`Can't append child, because it is already a child.`)
-    }
-
     childNode.parentNode = this
-
     if (this.lastChild) {
       childNode.prevSibling = this.lastChild
       this.lastChild.nextSibling = childNode