fix(core): fix Puppeteer launching issue on Linux

Chrome Headless fails to launch on some platforms due to sandbox issues.
See also https://github.com/GoogleChrome/puppeteer/blob/v1.0.0/docs/troubleshooting.md#chrome-headless-fails-due-to-sandbox-issues

We now launch Puppeteer with the `--no-sandbox` arg on any platform which
is not `win32` or `darwin`.

packages/ace-core/src/checker/checker-chromium.js

@@ -4,6 +4,7 @@ const fs = require('fs');
 const path = require('path');
 const pMap = require('p-map');
 const puppeteer = require('puppeteer');
+const os = require('os');
 const winston = require('winston');
 
 const axe2ace = require('@daisy/ace-report-axe');
@@ -80,7 +81,11 @@ async function checkSingle(spineItem, epub, browser) {
 }
 
 module.exports.check = async (epub) => {
-  const browser = await puppeteer.launch();
+  const args = [];
+  if (os.platform() !== 'win32' && os.platform() !== 'darwin') {
+    args.push('--no-sandbox')
+  }
+  const browser = await puppeteer.launch({ args });
   winston.info('Checking documents...');
   return pMap(epub.contentDocs, doc => checkSingle(doc, epub, browser), { concurrency: 4 })
   .then(async (results) => {

packages/jest-env-puppeteer/src/index.js

@@ -4,12 +4,17 @@
 
 const NodeEnvironment = require('jest-environment-node');
 const puppeteer = require('puppeteer');
+const os = require('os');
 
 class HeadlessChromeEnvironment extends NodeEnvironment {
 
   setup() {
+    const args = [];
+    if (os.platform() !== 'win32' && os.platform() !== 'darwin') {
+      args.push('--no-sandbox')
+    }
     return super.setup().then(() =>
-      puppeteer.launch().then((browser) => {
+      puppeteer.launch({ args }).then((browser) => {
         this.global.browser = browser;
       }));
   }