如果您有多个beforeEach,它们会始终运行吗?

beforeEach(function() {});
beforeEach(function() {});
beforeEach(function() {});
beforeEach(function() {});
beforeEach(function() {});

看来他们会的。我尝试用我的代码对其进行测试:
describe('Directive: Statement', function() {
  var el, scope, statements;

  beforeEach(module('simulatedSelves'));
  beforeEach(module('templates'));
  beforeEach(inject(function($compile, $rootScope) {
    console.log(1);
    scope = $rootScope.$new();

    statements = [];
    scope.statement = {
      text: 'test',
      arr: []
    };
    scope.statement.parent = statements;
    statements.push(scope.statement);

    el = angular.element('<statement statement=statement></statement>');
    $compile(el)(scope);
    scope.$digest();
  }));
  beforeEach(function() {
    var counter = 0;
    console.log(2);
    for (var i = 0; i < 1000000; i++) {
      counter++;
    }
    console.log(counter);
  });
  beforeEach(function() {
    console.log(3);
  });

  it('test statement has correct properties', function() {
    // stuff
  });
});

它记录:
1
2
1000000
3

由于带有较长beforeEach循环的for在记录3之前先将其内容注销,因此我认为beforeEach可以同步运行。真的吗?

最佳答案

是的,所有beforeEach都将按照您定义的顺序执行。

如果您深入研究Jasmine,最终将获得this definition:

Suite.prototype.beforeEach = function(fn) {
  this.beforeFns.unshift(fn);
};

添加describe时,Suite会生成并嵌套。每个Suite都使用this.beforeFns = []初始化,如您所见,它已添加到其中。请注意,unshift添加到了数组的左侧,因此您希望稍后定义的beforeEach首先运行。当 Jasmine 走到 child 套房的 parent 那里,收集所有beforeEach列表,然后反转它们以您想要的顺序运行时,它就是fixed later
var beforeAndAfterFns = function(suite) {
  return function() {
    var befores = [],
      afters = [];

    while(suite) {
      befores = befores.concat(suite.beforeFns);
      afters = afters.concat(suite.afterFns);

      suite = suite.parentSuite;
    }

    return {
      befores: befores.reverse(),
      afters: afters
    };
  };
};

Dan points out一样,到目前为止,我们假设您的所有beforeEach都是同步的。从Jasmine 2开始,您可以像这样设置异步beforeEach:
beforeEach(function(done) {
  setTimeout(function() {
    console.log('Async');
    done();
  }, 1000)
});

在运行时,Jasmine向您发送done函数,并异步执行if your function takes an argument。 (Function.length返回函数期望的参数数量)。
for(iterativeIndex = recursiveIndex; iterativeIndex < length; iterativeIndex++) {
  var queueableFn = queueableFns[iterativeIndex];
  if (queueableFn.fn.length > 0) {
    attemptAsync(queueableFn);
    return;
  } else {
    attemptSync(queueableFn);
  }
}
attemptAsync等待您调用done(),然后QueueRunner移至下一个beforeEach钩子(Hook),因此排序仍然有效!挺整洁的。
describe('beforeEach', function() {
  var data = null;

  beforeEach(function() { data = []; });
  beforeEach(function() { data.push(1); });
  beforeEach(function(done) {
    setTimeout(function() {
      data.push('Async');
      done();
    }, 1000);
  });
  beforeEach(function() { data.push(2); });
  beforeEach(function() { data.push(3); });

  it('runs in order', function(){
    expect(data).toEqual([1, 'Async', 2, 3]);
  });
});

关于javascript - Jasmine 的beforeEach同步吗?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/31492452/

10-12 06:36