monad-mock
A monad transformer for mocking mtl-style typeclasses
https://github.com/cjdev/monad-mock#readme
| LTS Haskell 11.22: | 0.2.0.0 |
| Stackage Nightly 2018-03-12: | 0.2.0.0 |
| Latest on Hackage: | 0.2.0.0 |
This version can be pinned in stack with:
monad-mock-0.2.0.0@sha256:16a15283f89f63c52ec60ef4bbd3f815359edf21f498a142d91ee6196ff727d2,2585Module documentation for 0.2.0.0
- Control
- Control.Monad
- Control.Monad.Mock
- Control.Monad.Mock.TH
- Control.Monad.Mock.TH.Internal
- Control.Monad.Mock.TH.Internal.TypesQuasi
- Control.Monad.Mock.TH.Internal
- Control.Monad.Mock.TH
- Control.Monad.Mock
- Control.Monad
Depends on 10 packages(full list with versions):
monad-mock 
monad-mock is a Haskell package that provides a monad transformer to help create “mocks” of mtl-style typeclasses, intended for use in unit tests. A mock can be executed by providing a sequence of expected monadic calls and their results, and the mock will verify that the computation conforms to the expectation.
For example, imagine a MonadFileSystem typeclass, which describes a class of
monads that may perform filesystem operations:
class Monad m => MonadFileSystem m where
readFile :: FilePath -> m String
writeFile :: FilePath -> String -> m ()
Using MockT, it’s possible to test computations that use MonadFileSystem
in a completely pure way:
copyFile :: MonadFileSystem m => FilePath -> FilePath -> m ()
copyFile a b = do
x <- readFile a
writeFile b x
makeMock "FileSystemAction" [ts| MonadFileSystem |]
spec = describe "copyFile" $
it "reads a file and writes its contents to another file" $
evaluate $ copyFile "foo.txt" "bar.txt"
& runMock [ ReadFile "foo.txt" :-> "contents"
, WriteFile "bar.txt" "contents" :-> () ]
For more information, see the documentation on Hackage.