angular-docs-cn/modules/@angular/platform-browser/testing/perf_util.ts

export {verifyNoBrowserErrors} from './e2e_util';

var benchpress = global['benchpress'];
var bind = benchpress.bind;
var Options = benchpress.Options;

export function runClickBenchmark(config) {
  browser.ignoreSynchronization = !config.waitForAngular2;
  var buttons = config.buttons.map(function(selector) { return $(selector); });
  config.work = function() { buttons.forEach(function(button) { button.click(); }); };
  return runBenchmark(config);
}

export function runBenchmark(config) {
  return getScaleFactor(browser.params.benchmark.scaling)
      .then(function(scaleFactor) {
        var description = {};
        var urlParams = [];
        if (config.params) {
          config.params.forEach(function(param) {
            var name = param.name;
            var value = applyScaleFactor(param.value, scaleFactor, param.scale);
            urlParams.push(name + '=' + value);
            description[name] = value;
          });
        }
        var url = encodeURI(config.url + '?' + urlParams.join('&'));
        return browser.get(url).then(function() {
          return global['benchpressRunner'].sample({
            id: config.id,
            execute: config.work,
            prepare: config.prepare,
            microMetrics: config.microMetrics,
            providers: [bind(Options.SAMPLE_DESCRIPTION).toValue(description)]
          });
        });
      });
}

function getScaleFactor(possibleScalings) {
  return browser.executeScript('return navigator.userAgent')
      .then(function(userAgent: string) {
        var scaleFactor = 1;
        possibleScalings.forEach(function(entry) {
          if (userAgent.match(entry.userAgent)) {
            scaleFactor = entry.value;
          }
        });
        return scaleFactor;
      });
}

function applyScaleFactor(value, scaleFactor, method) {
  if (method === 'log2') {
    return value + Math.log(scaleFactor) / Math.LN2;
  } else if (method === 'sqrt') {
    return value * Math.sqrt(scaleFactor);
  } else if (method === 'linear') {
    return value * scaleFactor;
  } else {
    return value;
  }
}