Write unit tests in Elm, support async Task out of the box, can run directly on Node or any major browsers.

Warning This is still a work in progress, API will probably change a bit before 1.0 release.

elm-package install pauldijou/elm-ordeal

port module Test exposing (..)

import Task
import Ordeal exposing (..)

main: Ordeal
main = run emit tests

port emit : Event -> Cmd msg

tests: Test
tests =
  describe "My first suite"
    [ test "My very first test" (
      "a" |> shouldEqual "a"
    )
    , describe "A sub-suite"
      [ test "And a sub-test" (
        { a = 1, b = False } |> shouldEqual { a = 1, b = False }
      )
      , test "Another sub-test" (
        True |> shouldNotEqual False
      )
      ]
    , xtest "A skipped test" (
      "a" |> shouldEqual "b"
    )
    , test "My first async test" (
      Task.succeed 42 
        |> andTest (\result ->
            case result of 
                Ok value ->
                    value |> shouldBeGreaterThan 35
                
                Err str ->
                    failure str
        )
    )
    , test "My first failure" (
      Task.fail { a = 1, b = "aze" } 
        |> andTest (\result -> 
            case result of 
                Ok _ -> 
                    failure "some hanlder"
                
                Err {a, b} ->
                    shouldEqual "54" b
        )
    )
    , test "Another failure" (
      ["a","b","c"] |> shouldContain "d"
    )
    ]

The easiest way is to use the elm-ordeal CLI with Yarn or NPM.

# NPM users
npm install --save-dev elm-ordeal
# Yarn users
yarn add --dev elm-ordeal

# Run
elm-ordeal your/TestFile.elm

# Learn
elm-ordeal --help

You could also update your package.json file:

{
  "scripts": {
    "test": "elm-ordeal your/TestFile.elm"
  }
}

# Then run the added script
npm test
yarn test

You can run your tests on the following environments, just specify the correct CLI argument when running elm-ordeal. Don't forget it's up to you to locally install any browser you want to use. If you don't provide any env, it will run as Node. You can specify several envs at once of course.

• Node (--node)
• Chrome (--chrome)
• Edge Explorer (--edge)
• Firefox (--firefox)
• Internet Explorer (--ie)
• Opera (--opera)
• Safari (--safari)

You can combine tests using Ordeal.and or Ordeal.or. Here is the result of combining two tests:

In case of two Failure, Ordeal.and will return the first one while Ordeal.or will return the second one.

You can also use Ordeal.all and Ordeal.any which works on list of tests just folding them using Ordeal.and and Ordeal.or respectively.

It's up to you, I think elm-test is good but when I started writing tests in Elm, I needed to test Task and there was no way to do it easily using elm-test (not sure if there is now). In elm-ordeal, all tests are tasks, so they can be can synchronous or asynchronous, the package does not care.

You can run the tests using yarn install && yarn test. Currently, the final result should be one timeout, one skipped and all other success.

A big thank to @rtfeldman for creating node-test-runner which I took a lot of inspiration from.

This software is licensed under the Apache 2 license, quoted below.

Copyright Paul Dijou (https://pauldijou.fr).

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this project except in compliance with the License. You may obtain a copy of the License at https://www.apache.org/licenses/LICENSE-2.0.

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.