I have read and understood the contribution guidelines.
Basically, charSpace and maxWidth don't play nicely together.
Code tested using your live demo at http://raw.githack.com/MrRio/jsPDF/master/
The following works fine ...
var doc = new jsPDF();
doc.setFontSize(22);
doc.text("This is a title", 20, 20);
const maxWidth = 100;
const charSpace = 0;
// Drawing a box to show maxWidth clearly
doc.rect(20, 20, maxWidth, 100, 'S')
// Using 'justify' to show things clearly but also happens with 'left'
const options = {
maxWidth: maxWidth,
charSpace: charSpace,
align: 'justify'
}
const str = "Mary had a little lamb she also had a duck. She put them on the mantlepiece to see if they would fall off."
doc.setFontSize(16);
doc.text(str, 20, 30, options);
However, if you change charSpace to 1 then maxWidth is not correctly applied and then text extends beyond the maxWidth boundary.

I can then adjust maxWidth to try and compensate for this, but the formula is not leaping off the page at me!
I have read and understood the contribution guidelines.
Basically,
charSpaceandmaxWidthdon't play nicely together.Code tested using your live demo at http://raw.githack.com/MrRio/jsPDF/master/
The following works fine ...
However, if you change
charSpaceto1thenmaxWidthis not correctly applied and then text extends beyond the maxWidth boundary.I can then adjust
maxWidthto try and compensate for this, but the formula is not leaping off the page at me!