Doc height resizing on need

I have a dynamic content to insert into PDF file. I don't really know in advance how much data will be present in the document, and I need to generate two PDF formats:

• A4 format
• Custom format (Fixed width + Dynamic height)

Let's say I have the following doc initialization:

var doc = new jsPDF('p', 'px', [1337, 420]);

I'm wondering if there's any possible way to remove the empty space left in the document If my content's height is lower than 1337, and how to expand the doc height in the opposite case.

Thanks!