Create Kotlin DSL for Spring RestDocs

I’ve been working on a Kotlin DSL for restDocs and have converted a number of samples to demonstrate it.

I would love to contribute the DSL into the spring-restdocs project. Would you be interested in that DSL? (I also wanted to contribute the base MockMVC DSL to spring test, but that is a different project)

Example DSL:

    @Test
    fun indexExample() {
        this.mockMvc.performGet("/") {
            expect { status { isOk } }
            document(documentationHandler) {
                "notes" link { description("The <<resources-notes,Notes resource>>") }
                "tags" link { description("The <<resources-tags,Tags resource>>") }
                response {
                    "Content-Type" header { description("The Content-Type of the payload, e.g. `application/hal+json`") }
                    "_links" subsection { description("<<resources-index-links,Links>> to other resources") }
                }
            }
        }
    }

[sdeleuze]

I agree with @jnizet, the inconsistency between infix and non infix form is an issue, which is also present with andReturn(), so I have removed it via this commit.

Snapshot builds of Spring Framework 5.2.0.BUILD-SNAPSHOT are available on https://repo.spring.io./snapshot.

[checketts]

I’m also in favor of @jnizet 's direction. So I’ll let him lead on his proposal while I focus on https://github.com/spring-projects/spring-framework/pull/1951

I like that the focus is ease of discoverabiliy, readability, and allowing extension points for further custom extension functions