Integrate browserstack into ci

scripts/e2e-browserstack.js

@@ -0,0 +1,51 @@
+#!/usr/bin/env node
+
+const Nightwatch = require('nightwatch');
+const browserstack = require('browserstack-local');
+const {onshutdown} = require('../bin/util');
+
+async function start() {
+  try {
+    const bs_local = new browserstack.Local();
+    process.mainModule.filename = './node_modules/.bin/nightwatch';
+
+    // Code to start browserstack local before start of test
+    console.log('Connecting local');
+    Nightwatch.bs_local = bs_local;
+
+    bs_local.start({
+      'key': process.env.BROWSERSTACK_KEY,
+      'logFile': './test/e2e/bslocal.log'
+    }, function(error) {
+      if (error) {
+        console.error(error);
+        throw error;
+      }
+
+      console.log('Connected. Now testing...');
+      Nightwatch.cli(function(argv) {
+        Nightwatch.CliRunner(argv)
+          .setup(null, function(){
+
+            // Code to stop browserstack local after end of parallel test
+            bs_local.stop(function(){});
+          })
+          .runTests(function(){
+
+            // Code to stop browserstack local after end of single test
+            bs_local.stop(function(){});
+          });
+      });
+    });
+
+    onshutdown([
+      () => bs_local.stop(function(){}),
+    ]);
+  } catch (ex) {
+    console.log('There was an error while starting the test runner:\n\n');
+    process.stderr.write(`${ex.stack}\n`);
+    process.exit(2);
+  }
+}
+
+start();