$(defaultMainGenerator) and imports

[decentral1se]

In the following snippet:

module Main where

import Test.Tasty
import Test.Tasty.TH
import Test.Tasty.Quickcheck

import AllMyPropTests

main :: IO ()
main = $(defaultMainGenerator)

If I have all my quickcheck properties defined (as prop_*) in test/AllMyPropTests, should the properties be picked up and run?

It isn't working for me so far, but I have a strange use case. I am trying to create a new Tasty plugin which does test discovery, and I think the API would be greatly improved by using tasty-th. The implementation is 'borrowed' from the awesome hspec and their discover implementation.

The Tasty plugins pre processed output will be the following code which will auto import all test modules under the users test directory. Then, the main generator would generate the boilerplate to run the tests.

I'd really like to get this working. Is there some TemplateHaskell limitation here? Any help really appreciated.

[bennofs]

The reason that this does not work is that tasty-th currently does the following:

• It uses TH to retrive the contents of the current source code file
• It then just uses some text processing to extract haskell function names from this file (see http://hackage.haskell.org/package/language-haskell-extract)

So perhaps, for your use case, I could add a function to generate a TestTree given a file name from which to read the properties? Since you already detect all the files, you could then just use that and write your main similar to this:

main :: IO ()
main = defaultMain $ testGroup "yourTestName"
  [ $(generateTestTree "FileFoo.hs")
  , $(generateTestTree "FIleBar.hs")
  , ...
  ]

Or even better, we could split the "detect the names of properties from a file" and "generate a test tree from property function names" into two separate functions, the first of which would take a file name.

[decentral1se]

Ah, right. I understand. It would be awesome if you could make that happen.

Also, generateTestTree could grab of all the case_* tests as well, I hope 👍

[bennofs]

Ok, you should now be able to use "extractTestFunctions" + "defaultMainGeneratorFor" to achieve your goal: just use extractTestFunctions in your plugin, and then generate a file which contains defaultMainGeneratorFor <name of the toplevel test group> <all found test functions>. I'll make a hackage release soon, after travis tests finish.

[decentral1se]

Brilliant, thank you, I will let you know how it goes when I get a chance 🚀

[bennofs]

You're welcome, hackage release is done.