Spring Cloud Contract Practice

CDC(Consumer Driven Contract)

Application Scenarios

Contract DSL(Domain-Specific Language)

• Groovy
• YAML
• Json

参考示例:
https://github.com/pact-foundation/pact-specification/tree/version-3

Producer

吧

定义测试Controller

@RestController
class OrderController {
    private val logger = LogManager.getLogger(OrderController::class.java)

    @GetMapping("/hello")
    fun hello(): ResponseEntity<Any> {
        logger.info("hello()")
        val user = User()
        user.name = "hello"
        return ResponseEntity(user, HttpStatus.OK)
    }
}

定义测试Controller的Contracts

在test的Resources下，新建contracts目录，定义一个contract文件，以json格式

{
  "provider": {
    "name": "Provider"
  },
  "consumer": {
    "name": "Consumer"
  },
  "interactions": [
    {
      "description": "",
      "request": {
        "method": "GET",
        "path": "/hello",
        "body": {
          "name": "hello"
        }
      },
      "response": {
        "status": 200,
        "body": {
          "name": "hello"
        }
      }
    }
  ],
  "metadata": {
    "pact-specification": {
      "version": "3.0.0"
    },
    "pact-jvm": {
      "version": "3.5.13"
    }
  }
}

定义测试基类ContractVerifierBase

通过配置build的插件spring-cloud-contract-maven-plugin使测试用例继承该类进行初始化操作

在test的com.example.base下，新建ContractVerifierBase.java

import io.restassured.module.mockmvc.RestAssuredMockMvc;
import org.junit.Before;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;
import org.springframework.test.web.servlet.setup.StandaloneMockMvcBuilder;

@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.MOCK)
public class ContractVerifierBase {
    @Before
    public void setup() {
        StandaloneMockMvcBuilder standaloneMockMvcBuilder = MockMvcBuilders.standaloneSetup(
            new TestController(),
            new TestHelloController()
        );
        RestAssuredMockMvc.standaloneSetup(standaloneMockMvcBuilder);
    }
}

需要特别注意的是，这个ContractVerifierBase只能是.java文件，目前不支持Kotlin

pom.xml

Attention: SpringBoot version must be <= 2.0.7.RELEASE

<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-contract-stub-runner</artifactId>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-contract-verifier</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

<build>
     <plugins>
        <plugin>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-contract-maven-plugin</artifactId>
            <version>${spring-cloud-contract.version}</version>
            <extensions>true</extensions>
            <configuration>
                 <!--   配置用例的基类   -->
                <baseClassForTests>com.example.base</baseClassForTests>
                <!--<packageWithBaseClasses>com.example.contracts</packageWithBaseClasses>-->
            </configuration>
            <dependencies>
                <dependency>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-contract-pact</artifactId>
                    <version>${spring-cloud-contract.version}</version>
                </dependency>
            </dependencies>
        </plugin>
     </plugins>
</build>

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>${spring-cloud.version}</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

Maven spring-cloud-contract-pact Plugin

• packageWithBaseClasses: Defines a package where all the base classes reside. This setting takes precedence over baseClassForTests. The convention is such that, if you have a contract under (for example) src/test/resources/contract/foo/bar/baz/ and set the value of the packageWithBaseClasses property to com.example.base, then Spring Cloud Contract Verifier assumes that there is a BarBazBase class under the com.example.base package. In other words, the system takes the last two parts of the package, if they exist, and forms a class with a Base suffix.

Example

测试基类目录：/test/com/example/contacts，此时com.example.contracts

Contract路径：/test/resouces/controller/controller_craete_order.json

生成的Contract测试类 -> ControllerTest

默认继承的基类 -> ControllerBase

Contracs Example

{
  "provider": {
    "name": "Provider"
  },
  "consumer": {
    "name": "Consumer"
  },
  "interactions": [
    {
      "description": "",
      "request": {
        "method": "PUT",
        "path": "/fraudcheck",
        "queryParameters": "nonce=1",
        "headers": {
          "Content-Type": "application/vnd.fraud.v1+json"
        },
        "body": {
          "clientId": "1234567890",
          "loanAmount": 99999
        },
        "generators": {
          "body": {
            "$.clientId": {
              "type": "Regex",
              "regex": "[0-9]{10}"
            }
          }
        },
        "matchingRules": {
          "header": {
            "Content-Type": {
              "matchers": [
                {
                  "match": "regex",
                  "regex": "application/vnd\\.fraud\\.v1\\+json.*"
                }
              ],
              "combine": "AND"
            }
          },
          "body": {
            "$.clientId": {
              "matchers": [
                {
                  "match": "regex",
                  "regex": "[0-9]{10}"
                }
              ],
              "combine": "AND"
            }
          }
        }
      },
      "response": {
        "status": 200,
        "headers": {
          "Content-Type": "application/vnd.fraud.v1+json;charset=UTF-8"
        },
        "body": {
          "fraudCheckStatus": "FRAUD",
          "rejectionReason": "Amount too high"
        },
        "matchingRules": {
          "header": {
            "Content-Type": {
              "matchers": [
                {
                  "match": "regex",
                  "regex": "application/vnd\\.fraud\\.v1\\+json.*"
                }
              ],
              "combine": "AND"
            }
          },
          "body": {
            "$.fraudCheckStatus": {
              "matchers": [
                {
                  "match": "regex",
                  "regex": "FRAUD"
                }
              ],
              "combine": "AND"
            }
          }
        }
      }
    }
  ],
  "metadata": {
    "pact-specification": {
      "version": "3.0.0"
    },
    "pact-jvm": {
      "version": "3.5.13"
    }
  }
}

Reference

https://springframework.guru/using-spring-cloud-contract-for-consumer-driven-contracts/
https://martinfowler.com/articles/consumerDrivenContracts.html