java - Spock 测试因 MissingPropertyException 失败

Question

我有一个简单的类，它根据简单的规则构建 RequestMessage。

• 如果在数据库中找到MessageMetadata，则会使用该元数据构建消息。
• 否则，消息将使用提供元数据的服务构建。

这是该类以及 Spock 测试。测试失败并出现 MissingPropertyException，表示找不到使用该服务创建的 RequestMessage。

class MessageService{
    MessageBuilder messageBuilder;
    MessageRepository messageRepository;
    MessageMetadaProvider messageMetaDataProvider;

    public RequestMessage getMessage(String id ) {
        try {
            MessageMetadata metadata = repository.findDefaulMessage(id);
            RequestMessage requestMessage = builder.createMessage(metadata);
            return requestMessage;
        } catch (DataNotFoundException e) {
            e.printStackTrace();
        }
        MessageMetadata metadata = messageMetaDataProvider.createNewMessageMetadata(id);
        RequestMessage message = messageBuilder.buildNew(id , metadata);
        return message;
    }
}

def "Build Request Message  "() {
    given:
    String id = '12345'
    MessageBuilder messageBuilder = Mock()
    MessageRepository messageRepository = Mock()
    MessageMetadaProvider messageMetaDataProvider = Mock()
    MessageService service = createMessageService(messageRepository,messageBuilder,messageMetaDataProvider)
    MessageMetadata metadata = new MessageMedata(id, MessageType.DEFAULT)
    when:
    RequestMessage requestMessage = messageService .getMessage(id )
    then:
    1 * messageRepository.repository.findDefaulMessage(id) >> {throw new DataNotFoundException("Not Found")}
    1 * messageMetaDataProvider.createNewMessageMetadata(id) >> metadata
    1  *  messageBuilder.buildNew(id , metadata) >> requestMessage
}

我真的很想了解为什么这不起作用。我很感谢您为成功测试此测试提供的任何帮助。谢谢

Answer 1

这个问题确实是我在对 jaco0646 的回答的评论中提到的母鸡与鸡蛋的问题。让我在 MCVE 中重现核心问题:

package de.scrum_master.stackoverflow.q60143388;

public class RequestMessage {}

package de.scrum_master.stackoverflow.q60143388;

public class MessageService {
  MessageBuilder messageBuilder;

  public RequestMessage getMessage(String id) {
    return messageBuilder.buildNew(id);
  }
}

package de.scrum_master.stackoverflow.q60143388

import spock.lang.Specification

class MessageServiceTest extends Specification {
  def "build request message"() {
    given:
    def id = "12345"
    MessageBuilder messageBuilder = Mock()
    MessageService messageService = new MessageService()
    messageService.messageBuilder = messageBuilder

    when:
    RequestMessage requestMessage = messageService.getMessage(id)

    then:
    1 * messageBuilder.buildNew(id) >> requestMessage
  }
}

这将产生:

groovy.lang.MissingPropertyException: No such property: requestMessage for class: de.scrum_master.stackoverflow.q60143388.MessageServiceTest

    at de.scrum_master.stackoverflow.q60143388.MessageServiceTest.build request message(MessageServiceTest.groovy:17)

仅按照 jaco0646 建议在 given: block 中声明 requestMessage，然后将其用作 stub 结果，这并不能单独完成。您需要确保首先声明一个由构建器方法返回的对象(例如模拟)，但将测试下的方法调用的结果分配给另一个变量，以便您可以比较两者或执行您喜欢执行的任何验证:

package de.scrum_master.stackoverflow.q60143388

import spock.lang.Specification

class MessageServiceTest extends Specification {
  def "build request message"() {
    given:
    def id = "12345"
    RequestMessage requestMessage = Mock()
    MessageBuilder messageBuilder = Mock()
    MessageService messageService = new MessageService()
    messageService.messageBuilder = messageBuilder

    when:
    RequestMessage result = messageService.getMessage(id)

    then:
    1 * messageBuilder.buildNew(id) >> requestMessage
    result.toString().startsWith("Mock for type 'RequestMessage'")
  }
}

现在测试通过了，您的引导问题也已解决。您不能通过方法调用创建对象，然后同时将其指定为预期的 stub 结果。这没有逻辑意义。