Convert HTML + CSS to PDF with nodeJS or Javascript?

This is a difficult problem. I have also found that existing HTML to PDF libraries usually don't handle the HTML & CSS that I throw at them.

The best solution I have found is not Javascript at all: wkhtmltopdf. This is essentially a program that wraps up the webkit rendering engine so that you can give it any HTML + CSS that webkit can render and it will return a PDF document. It does an outstanding job, since it's actually rendering the document just like a browser would.

You mention that you're using node.js, but it's not clear exactly what your environment is, so I'm going assume that your report is available at a URL like http://my.domain/phase_one_report.html. The simplest way to get this working would be to install the wkhtmltopdf application on your server, then use child_process.exec to execute it.

For example:

import { exec } from 'child_process';

// generate the report

// execute the wkhtmltopdf command
exec(
    'wkhtmltopdf http://my.domain/phase_one_report.html output_file.pdf',
    (error) => {
        // send the PDF file to the client
    }
);

There are a lot of different command-line options for wkhtmltopdf - you'll need to look into all the different ways to configure it.

If your report is not accessible at a URL, then this becomes a little more complicated - you'll need to inline the CSS and send everything to wkhtmltopdf at once.