在量角器中创建和解决承诺

这是一个用于Protractor中的用户定义函数的工作示例，该函数创建并实现（或拒绝）promise：

// Get the text of an element and convert to an integer.// Returns a promise.function getTextAsInteger(element, radix) {  // Specify a default radix for the call to parseInt.  radix = radix || 10;  // Create a promise to be fulfilled or rejected later.  var deferred = protractor.promise.defer();  // Get the text from the element. The call to getText  // returns a promise.  element.getText().then(    function success(text) {      var num = parseInt(text, radix);      if (!isNaN(num)) {        // Successfully converted text to integer.        deferred.fulfill(num);      } else {        // Error converting text to integer.        deferred.reject('could not parse "$1" into an integer'          .replace('$1', text));      }    },    function error(reason) {      // Reject our promise and pass the reason from the getText rejection.      deferred.reject(reason);    });  // Return the promise. This will be resolved or rejected  // when the above call to getText is resolved.  return deferred.promise;}

该函数以

element

getText()

getText()

getText()

要使用此功能，请传递一个元素promise：

var numField = element(by.id('num-field'));getTextAsInteger(numField).then(    function success(num) {        console.log(num);    },     function error(reason) {        console.error(reason);    });

要么：

var numField = element(by.id('num-field'));expect(getTextAsInteger(numField)).toEqual(jasmine.any(Number));expect(getTextAsInteger(numField)).toBeGreaterThan(0);