存根回调函数

Stub a Function with Callback

通常我使用这个代码:

  aws_stub.S3 = function(){};
  var fake_aws_listObjects = function(params, func){func("failure", null)};
  var fake_aws_listObjects_stub = sinon.spy(fake_aws_listObjects);
  aws_stub.S3.prototype.listObjects = fake_aws_listObjects_stub;

存根函数,如下所示:

new AWS.S3().listObjects(that.build_params(), function(err, data) {
  if(err){
    that.make_failure_callback();
  }
  else{
    that.add_keys(data);

    if(data.IsTruncated){
      that.make_request(data.NextMarker);
    }else{
      that.make_success_callback(that.keys);
    }
  }
});

这个存根的问题每个请求returns相同

现在我想为每个调用做不同的存根:

  aws_stub.S3 = function(){};
  var fake_aws_truncated = function(params, func){func(null, {
    Contents: [{Key: "3fb252ba-0724-438c-93b6-8cd0fd972a8e/image/1:::2.jpg"}],
    IsTruncated: true,
    NextMarker: "nextMarker"
    })};
  var fake_aws_listObjects = function(params, func){func(null, {Contents: [{
    Key: "3fb252ba-0724-438c-93b6-8cd0fd972a8e/image/2:::3.jpg"
  }]})};

  var fake_aws_listObjects_stub = sinon.stub();
     fake_aws_listObjects_stub.onCall(0).returns(fake_aws_truncated);
      fake_aws_listObjects_stub.onCall(1).returns(fake_aws_listObjects);

  aws_stub.S3.prototype.listObjects = fake_aws_listObjects_stub;

问题好像是returns,没有执行函数!!

我也不会这样写:

fake_aws_listObjects_stub.onCall(0) = fake_aws_truncated;

因为这会是一个错误的手写作业!

我需要更改什么?这是 sinon 文档:http://sinonjs.org/docs/

谢谢!!

我可能会换一种方式。

如果你想存根 AWS.S3.prototype.listObjects,我会这样做:

var stub = sinon.stub(AWS.S3.prototype, 'listObjects');

要使用各种值调用回调,请使用 stub.yields():

stub.onCall(0).yields(null, {
  Contents    : [{Key: "3fb252ba-0724-438c-93b6-8cd0fd972a8e/image/1:::2.jpg"}],
  IsTruncated : true,
  NextMarker  : "nextMarker"
});

stub.onCall(1).yields(null, {
  Contents : [{Key: "3fb252ba-0724-438c-93b6-8cd0fd972a8e/image/2:::3.jpg"}]
});

要测试您的代码,您只需像以前一样调用 listObjects

var s3 = new AWS.S3();
s3.listObjects(params, function(err, value) {
  ...`value` is now one of the fixtures you declared above...
});

要恢复到原始版本的方法,请使用以下之一:

stub.restore();
// OR:
AWS.S3.prototype.listObjects.restore();