Dynamic check if text Goes to next page and add pagebreak in pdf using pdfmake

Found the solution :)

In the DocDefinition you can add a function for pageBreakBefore like this:

content: [{
    text: getOfferClosingParagraph(),
    id: 'closingParagraph'
  }, {
    text: getSignature(),
    id: 'signature'
  }],
  pageBreakBefore: function(currentNode, followingNodesOnPage, nodesOnNextPage, previousNodesOnPage) {
    //check if signature part is completely on the last page, add pagebreak if not
    if (currentNode.id === 'signature' && (currentNode.pageNumbers.length != 1 || currentNode.pageNumbers[0] != currentNode.pages)) {
      return true;
    }
    //check if last paragraph is entirely on a single page, add pagebreak if not
    else if (currentNode.id === 'closingParagraph' && currentNode.pageNumbers.length != 1) {
      return true;
    }
    return false;
  },

For more info about this function and the information provided take a look at this

The pageBreakBefore function gives a lot of flexibility in determining whether the page break is required or not. However, I've found one more solution which is more straightforward and less documented but does all the magic automatically. It's a unbreakable: true attribute that came in 0.1.32 release. Also, it mentioned in the following thread https://github.com/bpampuch/pdfmake/issues/1228#issuecomment-354411288

How it works? For instance, you want to make a header and some text below it to be unbreakable. In order to do it, you have to wrap the header and the content in a stack and apply the unbreakable: true on it.

{
    stack: [
        // header
        {
            text: 'Lorem ipsum dolor sit amet',
            bold: true,
            fontSize: 13
        },
        // content
        {
            text: 'Nulla iaculis magna vitae luctus euismod. Sed arcu risus, mattis non molestie et, condimentum sit amet justo. Quisque vitae neque magna. Etiam in tellus vitae arcu volutpat bibendum. In ullamcorper ante tortor, a viverra libero cursus eu. Phasellus quis massa nec lorem feugiat ultricies. Aliquam erat volutpat. Nullam a purus tempus, feugiat elit vel, tincidunt tortor.'
        }
    ],
    unbreakable: true // that's the magic :)
}