I’ve just released Konsent, an acceptance testing library for Kotlin.

The basic idea is that you can write your tests in a nice IDE-friendly and refactorable Kotlin DSL, but they generate Gherkin that your customer can read and approve as the spec.

So you write this

@RunWith(Konsent::class)
@Preamble(
    "As a developer named Duncan",
    "I want to know that example.com is up and running")
class KonsentExampleTests : ChromeAcceptanceTest() {

    val duncan = actorNamed("Duncan")

    @Scenario(1) fun `Example_dot_com loads`() {
        Given(duncan).loadsThePageAt("http://example.com")
        Then(duncan) {
            shouldSee(::`the page location`, pathContains("example.com"))
            shouldSee(::`the page title`, equalTo("Example Domain"))
            shouldSee(::`the page content`, containsALink("More information...", "http://www.iana.org/domains/example"))
        }
    }

    @Scenario(2, "Following a link from example.com") fun cant_have_dots_in_quoted_method_names() {
        Given(duncan).loadsThePageAt("http://example.com")
        When(duncan).followsTheLink("More information...", "http://www.iana.org/domains/example")
        Then(duncan).shouldSee(::`the page location`, equalTo(URI("http://www.iana.org/domains/reserved")))
    }

    @Scenario(3) fun `Dispensing with the given when then`() {
        duncan.he.loadsThePageAt("http://example.com")
        duncan.he.followsTheLink("More information...", "http://www.iana.org/domains/example")
        duncan.shouldSee(::`the page location`, equalTo(URI("http://www.iana.org/domains/reserved")))
    }
}

and they read this

Feature: Konsent Example Tests
    As a developer named Duncan
    I want to know that example.com is up and running

    Scenario: Example_dot_com loads
        Given Duncan loads the page at "http://example.com"
        Then Duncan sees the page location "location contains "example.com"
        and Duncan sees the page title is equal to "Example Domain"
        and Duncan sees the page content contains a link [More information...](http://www.iana.org/domains/example)

    Scenario: Following a link from example.com
        Given Duncan loads the page at "http://example.com"
        When Duncan follows the link [More information...](http://www.iana.org/domains/example)
        Then Duncan sees the page location is equal to http://www.iana.org/domains/reserved

    Scenario: Dispensing with the given when then
        Duncan loads the page at "http://example.com"
        Duncan follows the link [More information...](http://www.iana.org/domains/example)
        Duncan sees the page location is equal to http://www.iana.org/domains/reserved

Thanks to my patrons at Springer Nature, on whose dime this approach has been developed. We’re hiring, so get in touch if you’re in London and this stuff interests you.

Stay tuned - I’m planning a post soon on how to implement a DSL like this in Kotlin.