Spring Cloud Contract Verifier - Body matching - spring-boot

Question

I'm using Spring Cloud Contract Verifier
org.springframework.cloud:spring-cloud-starter-contract-verifier:jar:2.0.0.M8
org.springframework.cloud:spring-cloud-contract-maven-plugin:1.2.4.RELEASE
And I have the following contract:
request:
method: GET
url: /cars/list
response:
status: 200
headers:
Content-Type: application/json;charset=UTF-8
body:
cars:
[
{
"make": "Ford",
"model": "Fiesta",
"year": 2016,
"price": 16500.50
},
{
"make": "BMW",
"model": "X1",
"year": 2014,
"price": 22000.00
},
{
"make": "NISSAN",
"model": "Juke",
"year": 2017,
"price": 19300.00
}
]
Which is then converted in following java code:
DocumentContext parsedJson = JsonPath.parse(response.getBody().asString());
assertThatJson(parsedJson).array("['cars']").contains("['model']").isEqualTo("Juke");
assertThatJson(parsedJson).array("['cars']").contains("['make']").isEqualTo("Ford");
assertThatJson(parsedJson).array("['cars']").contains("['year']").isEqualTo(2014);
assertThatJson(parsedJson).array("['cars']").contains("['year']").isEqualTo(2016);
assertThatJson(parsedJson).array("['cars']").contains("['model']").isEqualTo("Fiesta");
assertThatJson(parsedJson).array("['cars']").contains("['make']").isEqualTo("BMW");
assertThatJson(parsedJson).array("['cars']").contains("['year']").isEqualTo(2017);
assertThatJson(parsedJson).array("['cars']").contains("['make']").isEqualTo("NISSAN");
assertThatJson(parsedJson).array("['cars']").contains("['price']").isEqualTo(16500.5);
assertThatJson(parsedJson).array("['cars']").contains("['model']").isEqualTo("X1");
assertThatJson(parsedJson).array("['cars']").contains("['price']").isEqualTo(22000.0);
assertThatJson(parsedJson).array("['cars']").contains("['price']").isEqualTo(19300.0);
I have a few issues with this test:
1) It does not take order into account, meaning the following body would still be considered valid:
{
"cars": [
{
"make": "NISSAN",
"model": "Juke",
"year": 2017,
"price": 19300.00
},
{
"make": "BMW",
"model": "X1",
"year": 2014,
"price": 22000.00
},
{
"make": "Ford",
"model": "Fiesta",
"year": 2016,
"price": 16500.50
}
]
}
2) It just verifies that certain property is present anywhere in the response, meaning the following body would still be considered valid:
{
"cars": [
{
"make": "Ford",
"model": "Juke",
"year": 2016,
"price": 19300.00
},
{
"make": "BMW",
"model": "X1",
"year": 2017,
"price": 22000.00
},
{
"make": "NISSAN",
"model": "Fiesta",
"year": 2014,
"price": 16500.50
}
]
}
3) It ignores any extra values present in the response, meaning the following body would still be considered valid:
{
"cars": [
{
"make": "Ford",
"model": "Fiesta",
"year": 2017,
"price": 22000.00,
"state": "good"
},
{
"make": "NISSAN",
"model": "Juke",
"year": 2016,
"price": 19300.00,
"state": "ok"
},
{
"make": "BMW",
"model": "X1",
"year": 2014,
"price": 16500.50
},
{
"make": "Volkswagen",
"model": "Golf",
"year": 2018,
"price": 12500.00,
"state": "new"
}
]
}
I would like the generated test to be more strict and fail on any differences outlined in cases above.
Can it be achieved with Spring Cloud Contract Verifier?

Answer 1

To begin with you have a mismatch of versions
org.springframework.cloud:spring-cloud-starter-contract-verifier:jar:2.0.0.M8 org.springframework.cloud:spring-cloud-contract-maven-plugin:1.2.4.RELEASE
You are using a plugin in version different than the verifier. Those should match.
Now for your questions
1) It does not take order into account, meaning the following body would still be considered valid:
Yes, we don't test it out of the box. You can do it manually by providing your own JSON path matchers for the whole body (https://cloud.spring.io/spring-cloud-contract/single/spring-cloud-contract.html#contract-matchers)
2) It just verifies that certain property is present anywhere in the response, meaning the following body would still be considered valid:
Yeah, we assert that the structure is ok, that's the idea of contract tests. If you want more precise verifiactions use the matchers section (https://cloud.spring.io/spring-cloud-contract/single/spring-cloud-contract.html#contract-matchers)
3) It ignores any extra values present in the response, meaning the following body would still be considered valid:
And that's absolutely what you should be doing. Ignore unknown fields. You can read more about Postel's law here (https://en.wikipedia.org/wiki/Robustness_principle)
I would like the generated test to be more strict and fail on any differences outlined in cases above.
I think you're looking for a schema not a contract test or definition. You can use the Spring Rest Docs integration (https://cloud.spring.io/spring-cloud-contract/single/spring-cloud-contract.html#_generating_stubs_using_rest_docs) and over there enforce how exactly the stub must look like. But IMO (of course I don't know your domain) you're too restrictive.