// this script is from the example axe docs at https://github.com/dequelabs/axe-core/blob/develop/doc/examples/puppeteer/axe-puppeteer.js
// it is licensed MPL 2.0: https://github.com/dequelabs/axe-core/blob/develop/LICENSE

const puppeteer = require('puppeteer');
const axeCore = require('axe-core');
const { parse: parseURL } = require('url');
const assert = require('assert');

// Cheap URL validation
const isValidURL = input => {
    const u = parseURL(input);
    return u.protocol && u.host;
};

// node axe-puppeteer.js <url>
const url = process.argv[2];
assert(isValidURL(url), 'Invalid URL');

const main = async url => {
    let browser;
    let results;
    try {
        // Setup Puppeteer
        browser = await puppeteer.launch();

        // Get new page
        const page = await browser.newPage();
        await page.goto(url);

        // Inject and run axe-core
        const handle = await page.evaluateHandle(`
            // Inject axe source code
            ${axeCore.source}
            // Run axe
            axe.run()
        `);

        // Get the results from `axe.run()`.
        results = await handle.jsonValue();
        // Destroy the handle & return axe results.
        await handle.dispose();
    } catch (err) {
        // Ensure we close the puppeteer connection when possible
        if (browser) {
            await browser.close();
        }

        // Re-throw
        throw err;
    }

    await browser.close();
    return results;
};

main(url)
    .then(results => {
        console.log(JSON.stringify(results));
    })
    .catch(err => {
        console.error('Error running axe-core:', err.message);
        process.exit(1);
    });