1

How to test in Haskell: HSpec setup

 2 years ago
source link: https://dannypsnl.github.io/blog/2019/12/14/cs/how-to-test-haskell/
Go to the source link to view the article. You can view the picture content, updated content and better typesetting reading experience. If the link is broken, please click the button below to view the snapshot at that time.
neoserver,ios ssh client

How to test in Haskell: HSpec setup

Before you start to read, ensure you're using Cabal >= 3.0 to manage your project.

For a Haskell project, I usually use Cabal, do not have any special reason. In the xxx.cabal file, we can define some common dependencies by common block:

-- just let you know how does the file should look like
-- with full content people can understand the structure better
cabal-version:       3.0

name:                your-module
version:             0.1.0.0
license:             MIT
license-file:        LICENSE
author:              your-name
maintainer:          [email protected]
-- Extra files to be distributed with the package, such as examples or a
-- README.
extra-source-files:  CHANGELOG.md

-- Common block
common shared-properties
  default-language: Haskell2010
  build-depends:
    base == 4.*, mtl >= 2.2
  ghc-options:
    -Wall

Then we can add test-suite block like this:

-- common block at here
library
  import: shared-properties
  exposed-modules:     YourModule
  other-modules:
  -- Directories containing source files.
  hs-source-dirs:      src
  default-language:    Haskell2010

test-suite spec
  import: shared-properties
  type: exitcode-stdio-1.0
  other-modules: YourModuleSpec SpecHelper
  hs-source-dirs: test
  main-is: Spec.hs
  build-depends: hspec >= 2.7
                 , hspec-discover >= 2.7
                 , your-module
  default-language:    Haskell2010

Create $project-path/test/Spec.hs and put:

{-# OPTIONS_GHC -F -pgmF hspec-discover #-}

And create $project-path/test/SpecHelper.hs and put:

module SpecHelper (
  module Test.Hspec
) where

import Test.Hspec

Finally, create $project-path/test/YourModuleSpec.hs and put:

module YourModuleSpec where
import SpecHelper
import YourModule

spec :: Spec
spec = describe "Your module" $ do
  context "has a function add can add two nature numbers" $ do
    (add 1 2) `shouldBe` 3

main :: IO ()
main = hspec spec

Then run commands:

cabal new-update
cabal new-install --only-dependencies
cabal install hspec-discover
cabal new-configure --enable-tests
cabal new-test

We finish the setup of testing now.


report

Recommend

About Joyk


Aggregate valuable and interesting links.
Joyk means Joy of geeK