Pfthb

I want to test a contract where one field is of type java.time.Instant. But not all instances of an Instant are handled as I expect by spring-cloud-contract. Given the following simple contract:

Contract.make 
 description("Get a version")
 request 
 method 'GET'
 url '/config/version'
 headers 
 contentType(applicationJson())
 
 
 response 
 status 200
 body(
 nr: 42,
 creationDate: producer(anyIso8601WithOffset())
 )
 headers 
 contentType(applicationJson())
 
 

And this service implementation:

@RestController
public class VersionController 
 @GetMapping(path = "/version")

 public ResponseEntity<Version> getCurrentVersion() 
 return ResponseEntity.ok(new Version(42, Instant.ofEpochMilli(0)));
 

Executing gradle test works fine. But if I replace the Instant with Instant.now(), my provider test fails with

java.lang.IllegalStateException: Parsed JSON ["nr":42,"creationDate":"2018-11-11T15:28:26.958284Z"] doesn't match the JSON path [$[?(@.['creationDate'] =~ /([0-9]4)-(1[0-2]|0[1-9])-(3[01]|0[1-9]|[12][0-9])T(2[0-3]|[01][0-9]):([0-5][0-9]):([0-5][0-9])(.d3)?(Z|[+-][01]d:[0-5]d)/)]]

which is understandable because Instant.now() produces an Instant whose string representation does indeed not match the anyIso8601WithOffset() pattern. But why is this? Why are Instants represented differently and how can I describe a contract that validates for any instant?

Ok, I found a solution that works for me. Although I do not know if this is the way to go.

In order to always get the exact same format of the serialized instant, I define the format of the corresponding property of my version bean as follows:

public class Version 
 private final int nr;
 private final Instant creationDate;

 @JsonCreator
 public Version(
 @JsonProperty("nr") int nr,
 @JsonProperty("creationDate") Instant creationDate)
 
 this.nr = nr;
 this.creationDate = creationDate;
 

 public int getNr() 
 return nr;
 

 @JsonFormat(pattern = "yyyy-MM-dd'T'HH:mm:ss.SSSX", timezone = "UTC")
 public Instant getCreationDate() 
 return creationDate;