Mar 10, 2021 · Mar 4, 2021 · Mar 4, 2021 · Mar 5, 2021 · Mar 10, 2021
diff --git a/__tests__/renderer/ViewNode.test.js b/__tests__/renderer/ViewNode.test.js
    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()

diff --git a/platform/nativescript/renderer/ViewNode.js b/platform/nativescript/renderer/ViewNode.js
      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.`
      )
      // 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)
      )
    }

    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
Original file line number	Diff line number	Diff line change
Expand Up		@@ -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()

Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -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.`
		)
Expand All		@@ -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)
Expand All		@@ -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
Expand Down