How it works

Cornichon tests are built around three core concepts: steps, session, and placeholders.

Steps are the building blocks of a scenario — each step either performs a side effect (like an HTTP request) or asserts an expected state. When a step produces a result, it is stored in the session, a key-value store that lives for the duration of a scenario. Values from the session can then be injected into later steps using placeholders like <my-key>, which are automatically resolved at runtime.

This simple model makes it natural to chain steps together: make a request, save part of the response, and use it in the next request — all without writing boilerplate code.

Quick example

Find below an example of testing the Open Movie Database API.

import com.github.agourlay.cornichon.CornichonFeature

class ReadmeExample extends CornichonFeature {

  def feature = Feature("OpenMovieDatabase API"){

    Scenario("list GOT season 1 episodes"){

      When I get("http://www.omdbapi.com").withParams(
        "t" -> "Game of Thrones",
        "Season" -> "1"
      )

      Then assert status.is(200)

      And assert body.ignoring("Episodes", "Response").is(
        """
        {
          "Title": "Game of Thrones",
          "Season": "1"
        }
        """)

      And assert body.path("Episodes").is(
        """
        |                Title                    |   Released   | Episode | imdbRating |   imdbID    |
        | "Winter Is Coming"                      | "2011-04-17" |   "1"   |    "8.1"   | "tt1480055" |
        | "The Kingsroad"                         | "2011-04-24" |   "2"   |    "7.8"   | "tt1668746" |
        | "Lord Snow"                             | "2011-05-01" |   "3"   |    "7.6"   | "tt1829962" |
        | "Cripples, Bastards, and Broken Things" | "2011-05-08" |   "4"   |    "7.7"   | "tt1829963" |
        | "The Wolf and the Lion"                 | "2011-05-15" |   "5"   |    "8.0"   | "tt1829964" |
        | "A Golden Crown"                        | "2011-05-22" |   "6"   |    "8.1"   | "tt1837862" |
        | "You Win or You Die"                    | "2011-05-29" |   "7"   |    "8.1"   | "tt1837863" |
        | "The Pointy End"                        | "2011-06-05" |   "8"   |    "7.9"   | "tt1837864" |
        | "Baelor"                                | "2011-06-12" |   "9"   |    "8.6"   | "tt1851398" |
        | "Fire and Blood"                        | "2011-06-19" |  "10"   |    "8.4"   | "tt1851397" |
        """)

      And assert body.path("Episodes").asArray.hasSize(10)

      And assert body.path("Episodes[0]").is(
        """
        {
          "Title": "Winter Is Coming",
          "Released": "2011-04-17",
          "Episode": "1",
          "imdbRating": "8.1",
          "imdbID": "tt1480055"
        }
        """)

      And assert body.path("Episodes[0].Released").is("2011-04-17")

      And assert body.path("Episodes[*].Released").is(
        """
        [
          "2011-04-17", "2011-04-24", "2011-05-01", "2011-05-08", "2011-05-15",
          "2011-05-22", "2011-05-29", "2011-06-05", "2011-06-12", "2011-06-19"
        ]
        """)

      And assert body.path("Episodes").asArray.contains(
        """
        {
          "Title": "Winter Is Coming",
          "Released": "2011-04-17",
          "Episode": "1",
          "imdbRating": "8.1",
          "imdbID": "tt1480055"
        }
        """)
    }
  }
}

For more examples see the following files which are part of the test pipeline:

And if you enjoy slides, you might like this presentation given at the Berlin Scala User Group which gives more context regarding the creation and usage of this library.

Ready to get started? Head over to Installation and then Basics.