download Chromium only when tests are run

.travis.yml

@@ -1,14 +1,10 @@
 language: node_js
 dist: trusty
-addons:
-  chrome: stable
 node_js:
 - 8
 - node
 env:
   - NODE_ENV=production
-before_install:
-  - google-chrome-stable --headless --no-sandbox --remote-debugging-port=9222 &
 install:
 - npm --production=false install
 - npm --production=false update

package.json

@@ -36,7 +36,7 @@
     "gh-pages": "^1.0.0",
     "jsdoc": "^3.5.5",
     "json": "^9.0.4",
-    "puppeteer": "^2.0.0",
+    "puppeteer-core": "^2.0.0",
     "scratch-vm": "0.2.0-prerelease.20191227164934",
     "tap": "^11.0.0",
     "travis-after-all": "^1.4.4",

test/helper/download-chromium.js

@@ -0,0 +1,24 @@
+const packageJson = require('puppeteer-core/package.json');
+const puppeteer = require('puppeteer-core');
+
+const fetcher = puppeteer.createBrowserFetcher();
+const revision = packageJson.puppeteer.chromium_revision;
+
+/* eslint-disable no-console */
+module.exports = async () => {
+    const downloadedRevisions = await fetcher.localRevisions();
+    if (downloadedRevisions.indexOf(revision) !== -1) {
+        console.log('Chromium already downloaded');
+        return Promise.resolve();
+    }
+
+    console.log('Downloading Chromium...');
+    return fetcher.download(revision)
+        .then(() => {
+            console.log('Downloaded Chromium successfully');
+        })
+        .catch(error => {
+            console.error(error);
+            process.exit(1);
+        });
+};

test/integration/pick-tests.js

@@ -1,8 +1,10 @@
 /* global vm, render, Promise */
-const puppeteer = require('puppeteer');
+const puppeteer = require('puppeteer-core');
 const test = require('tap').test;
 const path = require('path');
 
+const downloadChromium = require('../helper/download-chromium');
+
 const indexHTML = path.resolve(__dirname, 'index.html');
 const testDir = (...args) => path.resolve(__dirname, 'pick-tests', ...args);
 
@@ -19,6 +21,7 @@ const runFile = async (file, action, page, script) => {
 
 // immediately invoked async function to let us wait for each test to finish before starting the next.
 (async () => {
+    await downloadChromium();
     const browser = await puppeteer.launch();
     const page = await browser.newPage();
 

test/integration/scratch-tests.js

@@ -1,9 +1,11 @@
 /* global vm, Promise */
-const puppeteer = require('puppeteer');
+const puppeteer = require('puppeteer-core');
 const test = require('tap').test;
 const path = require('path');
 const fs = require('fs');
 
+const downloadChromium = require('../helper/download-chromium');
+
 const indexHTML = path.resolve(__dirname, 'index.html');
 const testDir = (...args) => path.resolve(__dirname, 'scratch-tests', ...args);
 
@@ -103,6 +105,7 @@ const testFile = (file, page) => test(file, async t => {
 
 // immediately invoked async function to let us wait for each test to finish before starting the next.
 (async () => {
+    await downloadChromium();
     const browser = await puppeteer.launch();
     const page = await browser.newPage();