routes.js

const { check } = require('express-validator');

module.exports.register = function(app) {
    app.get('/', (req, res) => res.send(`Welcome! Please see check <a href="https://github.com/MrClemRkz/pdf-generate-service">here</a> if you're looking for the api docs`))
    app.post('/generate', [
        check('url').isURL({require_valid_protocol: true, allow_protocol_relative_urls: false, require_tld: true}).optional(),
        check('html').optional(),
        check('file').optional(),
        check('url_html_file').custom((value, {req}) => {
            if (!req.body.html && !req.body.url && !req.body.file) {
                throw new Error("Must provide either url, html or file data");
            }

            return true;
        }),
        check('scale').custom((value, {req}) => {
            if (!value) {
                return true;
            }
            if (Number.isNaN(value) || value < 0.1 || value > 2) {
                throw new Error("scale must be between 0.1 and 2");
            }

            return true;
        }),
        check('displayHeaderFooter').isBoolean().optional(),
        check('headerTemplate').optional(),
        check('footerTemplate').optional(),
        check('printBackground').isBoolean().optional(),
        check('landscape').isBoolean().optional(),
        check('pageRanges').custom((value, {req}) => {
            if (!value) {
                return true; // optional
            }

            const pageRanges = value.split('-');
            if (Number.isNaN(pageRanges[0]) || Number.isNaN(pageRanges[1])) {
                throw new Error("Invalid page range. Must be like 2-5");
            }

            return true;
        }),
        check('format').custom((value, {req}) => {
            if (!value) {
                return true;
            }

            const options = ['Letter', 'Legal', 'Tabloid', 'Ledger', 'A0', 'A1', 'A2', 'A3', 'A4', 'A5', 'A6'];

            if (options.indexOf(value) === -1) {
                throw new Error(`format must be one of ${options.join(',')}`);
            }

            return true;
        }),
        check('width').isNumeric().optional(),
        check('height').isNumeric().optional(),
        check('margin.top').isNumeric().optional(),
        check('margin.right').isNumeric().optional(),
        check('margin.bottom').isNumeric().optional(),
        check('margin.left').isNumeric().optional(),
        check('preferCSSPageSize').isBoolean().optional()
    ], require('./handlers/generate'));

    return app;
}