用于AWS X-Ray呼叫的Sinon存根

Question

我正在尝试为AWS X-Ray调用设置存根，以便在AWS外部单元测试NodeJS Lambdas。

我在我的lambda中有下面的代码。我如何使用sinon来存根出下面所示的对AWSXRay应用程序接口的调用？getSegment()调用必须被存根，然后“链接”，这样我才能调用addNewSubSegment(parm)？

const AWSXRay = require('aws-xray-sdk-core');
...

const rootSubSegment = AWSXRay.getSegment().addNewSubsegment("RootSubSegment");
rootSubSegment.addAnnotation("MyAnnotationKey", "MyAnnotationData");
rootSubSegment.addMetadata("MyMetaDataKey", "MyMetaData");

const s3SubSegment = AWSXRay.getSegment().addNewSubsegment("Do S3 Stuff");
...
s3SubSegment.close();

rootSubSegment.close();

Answer 1

要返回具有存根addNewSubsegment属性的对象，只需存根getSegment即可。

看起来，您的代码在需要时就会运行，因此在测试中需要代码之前，您需要确保存根已经就位。

下面是一个可操作的示例测试，帮助您开始：

const AWSXRay = require('aws-xray-sdk-core');
const sinon = require('sinon');

describe('code', () => {
  it('should add subsegments', () => {
    const getSegmentStub = sinon.stub(AWSXRay, 'getSegment');
    const addNewSubsegmentStub = sinon.stub();
    getSegmentStub.returns({ addNewSubsegment: addNewSubsegmentStub });
    const rootSubSegmentMock = {
      addAnnotation: sinon.spy(),
      addMetadata: sinon.spy(),
      close: sinon.spy()
    }
    const s3SubSegmentMock = {
      close: sinon.spy()
    }
    addNewSubsegmentStub.onFirstCall().returns(rootSubSegmentMock);
    addNewSubsegmentStub.onSecondCall().returns(s3SubSegmentMock);

    require('[path to your code]');  // <= now require the code to run it

    sinon.assert.calledWithExactly(addNewSubsegmentStub.firstCall, 'RootSubSegment');  // Success!
    sinon.assert.calledWithExactly(addNewSubsegmentStub.secondCall, 'Do S3 Stuff');  // Success!
    sinon.assert.calledWithExactly(rootSubSegmentMock.addAnnotation, 'MyAnnotationKey', 'MyAnnotationData');  // Success!
    sinon.assert.calledWithExactly(rootSubSegmentMock.addMetadata, 'MyMetaDataKey', 'MyMetaData');  // Success!
    sinon.assert.called(s3SubSegmentMock.close);  // Success!
    sinon.assert.called(rootSubSegmentMock.close);  // Success!
  })
})