Use assert{Bool,Failure} from tasty-hunit

[andreasabel]

Use assert{Bool,Failure} from tasty-hunit rather than hunit. Gives better error printing.

Before:

    Accept GHC 9.2 LANGUAGE extensions: FAIL
      Exception: HUnitFailure (Just (SrcLoc {srcLocPackage = "main", srcLocModule = "Main", srcLocFile = "tests/PackageTestMain.hs", srcLocStartLine = 118, srcLocStartCol = 34, srcLocEndLine = 118, srcLocEndCol = 45})) (Reason "Expected success, but got: \"Unknown extensions: GarbageBlargh\"")

After:

    Accept GHC 9.2 LANGUAGE extensions: FAIL
      tests/PackageTestMain.hs:117:
      Expected success, but got: "Unknown extensions: GarbageBlargh"

Background

Following the discussion at UnkindPartition/tasty#327 (comment) :

@andreasabel wrote:
There is a Show instance for HUnitFailure which gives the Haskell representation of this exception. So far so good.

I am looking for a function that pretty-prints the exception, for presentation to the user.
It should look nicer than what Show gives me:

      Exception: HUnitFailure (Just (SrcLoc {srcLocPackage = "main", srcLocModule = "Main", srcLocFile =
"tests/PackageTestMain.hs", srcLocStartLine = 127, srcLocStartCol = 3, srcLocEndLine = 127, srcLocEndCol =
17})) (Reason "Expected success but got: \"correct-package-0.1.0.0/correct-package.cabal:11:34: \\nunexpected
Unknown cabal spec version specified: 1.10123456\\nexpecting \\\".\\\", \\\"-\\\", white space, \\\"&&\\\" or \\\"||
\\\"\\n\"")

@VictorCMiraldo wrote:
I started working on this today but I couldn't reproduce the problem. Eventually I discovered that @andreasabel and I did something wrong. What we did is some variation on:

import qualified Test.HUnit as Raw
import qualified Test.Tasty.HUnit as Tasty

t1 = Tasty.testCase "Some Test" $ Raw.assertFailure "Omg"

The issue comes from the fact that Raw.HUnitAssertion is a different type altogether from Tasty.HUnitAssertion. Because Tasty.Assertion == Raw.Assertion == IO (), and failures are communicated through exceptions, we're bypassing the try on Tasty.HUnit.run and flagging the test as failed through a random exception, since that method is trying on Tasty.HUnitAssertion.

The solution is to not depend on HUnit, depend exclusively on tasty-hunit and use the functions from there. Your test failures will be printed properly then.