Dear café,

I want to implement a roundtrip test for a parser/prettyprinter combination. Let me try to explain what I am struggling with. I start with some type definitions of functions I have

data Guarded a =

Errors (NE.NonEmpty CtxError)
| Checked a [Warning]

parseFoo :: Text -> Guarded Foo

prettyFoo :: Foo -> Text

The idea is that for all foo :: Foo, the following holds:

parseFoo . prettyFoo $ foo should be equal to Checked foo []

Now, if there is a counterexample, I would like to see prettyFoo foo as output, folowed by the show of the Errors part.

I have been struggling to get this working, but without luck so far. I am not very familiar with Quickcheck, so that could be the problem too.

Any help would be appreciated!

Thanks

Han