如何在Spock中模拟一个类的单个方法？

Question

我在课堂上有一个类似下面的方法,我正在尝试测试:

class SomeHelper { 
    ByteArrayOutputStream fooBar (Request request) {
       ByteArrayOutputStream baos = someParser.parseData(getRequestFileInputStream(request.filename))
       return baos
    }
    InputStream getRequestFileInputStream(String filename) {
      //return intputStream of object from S3
    }
....
}

在上面,getRequestFileInputStream是一种将参数作为文件名的方法.它从AWS S3获取该文件的输入流.虽然fooBar从Spock 测试方法,我想为该getRequestFileInputStream方法提供一个模拟,因为我不想使用该类中此方法的实现,因为它转到另一个存储桶名称.

是否有可能做到这一点？

以下是我尝试过的内容:

class SomeHelperSpec extends Specification{
    //this is the implementation of getRequestFileInputStream I want to use while testing
    InputStream getObjectFromS3(String objectName) {
            def env = System.getenv()
            AwsClientBuilder.EndpointConfiguration endpoint = new AwsClientBuilder.EndpointConfiguration(env["endpoint_url"], env["region_name"])
            AmazonS3ClientBuilder builder = AmazonS3ClientBuilder.standard()
            builder.setEndpointConfiguration(endpoint)
            builder.setCredentials(new AWSStaticCredentialsProvider(new BasicAWSCredentials(env["ACCESS_KEY"], env["SECRET_KEY"])))
            AmazonS3 s3 = builder.build()
            return s3.getObject("testbucket", objectName).getObjectContent()

    }

    def "test fooBar" () {
      given: 
         someHelper = new SomeHelper()
         someHelper.getRequestFileInputStream(_) >> getObjectFromS3(fileName)
         someHelper.someParser = Mock(SomeParser) {
           ....
         }
         Request requestInstance = new Request()
         request.filename = fileName
         request.fileType = fileType
      expect:
         someHelper.fooBar(requestInstance).getText == returnVal

      where:
         fileType | fileName      | returnVal    
         "PDF"    | "somepdf.pdf" | "somereturnval"
    }
}

但是,上面的方法不起作用,因为它仍在尝试调用getRequestFileInputStreamin 的原始实现,SomeHelper而不是使用规范中提供的模拟实现.

Answer 1

您可以使用实际对象但使用重写方法:

given:
    someHelper = new SomeHelper() {
         @Override
         InputStream getRequestFileInputStream(String filename) {
             return getObjectFromS3(fileName)
         }
    }

Answer 2

你可以使用间谍

def someHelper = Spy(SomeHelper)
someHelper.getRequestFileInputStream(_) >> getObjectFromS3(fileName)

见间谍.