javascript - 强制 Protractor 的 onPrepare 等待异步 http 请求

Question

我的 Protractor conf.js，onPrepare 函数需要发出一个 http 请求，如下所示，

onPrepare: function(done) {
    request.get('http://pepper/sysid')
      .end(function(err, resp){
        if(err || !resp.ok){
          log("there is an error " + err.message)
          done()
        }else{
          global.sysid = resp.sysid
          done()
         }
      })

它抛出错误，done 不是一个函数

有没有其他方法可以在我的测试开始执行之前强制调用 onPrepare 中的回调？

Answer 1

onPrepare() 可以 optionally return a promise该 Protractor 将在开始执行测试之前解析:

onPrepare can optionally return a promise, which Protractor will wait for before continuing execution. This can be used if the preparation involves any asynchronous calls, e.g. interacting with the browser. Otherwise Protractor cannot guarantee order of execution and may start the tests before preparation finishes.

做一个 Protractor promise并从onPrepare()返回它:

onPrepare: function() {
    var defer = protractor.promise.defer();

    request.get('http://pepper/sysid').end(function(err, resp) {
        if (err || !resp.ok) {
            log("there is an error " + err.message);
            defer.reject(resp);
        } else {
            global.sysid = resp.sysid;
            defer.fulfill(resp);
        }
    });

    return defer.promise;
},