Example Gulpfile with Pagespeed Insights

gulpfile.js

var gulp = require('gulp');
var psi = require('psi');
var ngrok = require('ngrok');
var sequence = require('run-sequence');

// note server must already be running on port to be able to 
// run this example perfectly
var PORT = 8000;
var site = '';

gulp.task('ngrok', function(cb) {
  return ngrok.connect( PORT, function( err, url ) {
    site = url;
    cb(err);
  });
});

gulp.task('psi:desktop', function(cb) {
  psi( site, {
    nokey: 'true',
    strategy: 'desktop'
  }, function( error, data ) {
    psi.output( site, function( err ) {
      cb( err || error );
    });
  });
});

gulp.task('psi:mobile', function(cb) {
  psi( site, {
    nokey: 'true',
    strategy: 'mobile'
  }, function( error, data ) {
    psi.output( site, function( err ) {
      cb( err || error );
    });
  });
});

gulp.task('kill-process', function() {
  process.exit();
  // could also be ngrok disconnect with callback
});

gulp.task('psi', function(cb) {
  sequence(
    'ngrok',
    'psi:desktop',
    'psi:mobile',
    'kill-process'
    cb
  );
});