How do I mock a REST server with with multiple endpoints in the same test in Java?

user_6112306 0
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I'm trying to test a Java method that makes a request to a remote REST server to retrieve some JSON data, extracts an ID from that JSON, then uses the ID to make another request to the same server at a different endpoint.

Using Mockito's MockRestServiceServer, I can successfully mock and test a server that expects a single request to one endpoint, but it seems that I cannot use it to create a server with a set of predefined endpoints with their own expectations and responses.

How do I mock a server with multiple endpoints for the purpose of testing a single function that makes multiple, distinct requests to the remote server?

functional-testing mockito rest json java
2 Answers

So I was actually able to solve my problem. The trick is to manually create your own MockRestServiceServerBuilder to build your MockRestServiceServer instead of using the createServer(RestTemplate) or bindTo(RestTemplate).build() methods, like so:

MockRestServiceServer.MockRestServiceServerBuilder builder = 
    MockRestServiceServer.bindTo(restTemplate);
builder.ignoreExpectOrder(true);
MockRestServiceServer server = builder.build();

By doing so, the underlying RequestExpectationManager field in the MockRestServiceServer is initialized as an UnorderedRequestExpectationManager, allowing you to match requests regardless of the order in which they were made. This solved a lot of headaches for me.

user_61123060

My answer assumes you are using SpringBoot but the idea can be applied generically.

Make your class depend on the RestOperations interface so that you can pass a stub when testing.

Class Under Test

public class Foo {
  private final RestOperations restOperations;

  public Foo(RestOperations restOperations) {
    this.restOperations = restOperations;
  }
}

Test

  public void test() {
    Foo foo = new Foo(new MyStub());
  }

Depend on abstractions, not concrete implementations.

user_63510610
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