1. Recap

code example (This code use the Automatic Spec Discovery)

module <Module name>Spec where 
import Test.Hspec
import ModuleBeingTest.AandB

spec :: Spec 
spec = do                       -- more than one `describe`
    describe "FunctionA" $ 
        do                      -- more than one `it` 
            it "can do this with A" f1 `shouldBe` resultA1
            it "can do that with A" f2 `shouldBe` resultA2
    describe "FunctionB" $ 
        do  
            it "can do this with B" B1 `shouldBe` resultB1
            it "can do that with B" B2 `shouldBe` resultB2

stack test

<Module name>               -- Test Module name with no `Spec`
  FunctionA      -- Text after `describe`
     it can do this with A  -- Text after `it`
     it can do that with A
  FunctionB
     it can do this with B FAILED [1] -- Test FAIL!!
     it can do that with B

Failures:

  <file contains failed test>:20:63: 
  1) <Module name>  Test the test-suit, it can do this with B
       expected: <resultB1>
        but got: <B1>
...
Randomized with seed 1521981406
...
Finished in 0.0004 seconds
4 examples, 1 failure

...
    <project name>-test-suite:  exited with: ExitFailure 1
Logs printed to console

Test a particular describe

stact test --test-arguments=--match="<Module name>.FunctionB"
This will only test the second describe part FunctionB

TODO: This command doesn’t work if there is any space in the describe string

2. Automatic Spec Discovery in Stack Project

  1. Edit package.yaml > package.yaml is a wrapper of <projectname>.cabal. This free me from dealing with the differences between exitcode-stdio-1 and detailed-0.9, both are different cabal file types. > - package.yaml > - cabal keys

    tests: 
  source-dirs: test
  main: Spec.hs

  2. create folder test/ in project.

  3. create file Spec.hs in test/

    -- file test/Spec.hs
{-# OPTIONS_GHC -F -pgmF hspec-discover #-}

  4. creat test file TestOneSpec.hs or TestTwoSpec.hs in test/.

    • Assume TestOneSpec.hs is for ModelOne, etc.
    • These file names must end with Spec.hs.

    • Each file has to export a function spec of type Spec.

      spec :: Spec 
spec = do 
describe "Some functionality A" $  do
    it "can do this" f1 `shouldBe` resultA1
    it "can do that" f2 `shouldBe` resultA2
describe "Some functionality B" $  do
    it "can do this" B1 `shouldBe` resultB1
    it "can do that" B2 `shouldBe` resultB2

      Check official doc for more information.

3. Use QuickCheck together with Hspec

TODO