Groovy HTTPBuilder Mocking the Response - unit-testing

Question

I am trying to figure out how to write my Test cases for a service I am going to write.
The service will use HTTPBuilder to request a response from some URL. The HTTPBuilder request only needs to check the response for a success or failure. The service implementation will be be something as simple as:
boolean isOk() {
httpBuilder.request(GET) {
response.success = { return true }
response.failure = { return false }
}
}
So, I want to be able to mock the HTTPBuilder so that I can set the response to be either success/failure in my test so I can assert that my service's isOk method returns True when the response is a success and False, when the response is a failure.
Can any one help with how I can mock the HTTPBuilder request and set the response in a GroovyTestCase?

Answer 1

Here's a minimal example of a mock HttpBuilder that will handle your test case:
class MockHttpBuilder {
def result
def requestDelegate = [response: [:]]
def request(Method method, Closure body) {
body.delegate = requestDelegate
body.call()
if (result)
requestDelegate.response.success()
else
requestDelegate.response.failure()
}
}
If the result field is true, it'll invoke the success closure, otherwise failure.
EDIT: Here's an example using MockFor instead of a mock class:
import groovy.mock.interceptor.MockFor
def requestDelegate = [response: [:]]
def mock = new MockFor(HttpBuilder)
mock.demand.request { Method method, Closure body ->
body.delegate = requestDelegate
body.call()
requestDelegate.response.success() // or failure depending on what's being tested
}
mock.use {
assert isOk() == true
}