Usage

In any file, you can specify tests above a function declaration, like:

 --[1 2 3]
 add x y = x+y
 

Later, on your test file, you can build tests functions with

 {-# LANGUAGE TemplateHaskell #-}
 $(makeAllTests "some/Path/File.hs")
 

and use the produced function in your main:

 import System.Exit

 main :: IO ()
 main = do
   let (str,res) = _TEST_some_Path_File
   putStrLn str
   if res then exitSuccess else exitFailure
 

If you want to make tests on the actual file, you can use

 $(makeAllTestsHere)
 

the function produced will be equivalent to the one produced by

 $(makeAllTests "path/to/file/known/by/ghc")
 

String produced

Considering the given file:

 --[1 2 3]
 --[1 2 4]
 add x y = x+y
 

The string produced will be:

 Test passed: add 1 2  == 3
 Error: add 1 2 /= 4 BUT == 3