[Haskell-cafe] What is the state of the art in testing code generation?

[Tom Ellis]

I am implementing an EDSL that compiles to SQL and I am wondering what is
the state of the art in testing code generation.

All the Haskell libraries I could find that deal with SQL generation are
tested by implementing multiple one-off adhoc queries and checking that when
either compiled to SQL or run against a database they give the expected,
prespecified result.

 * https://github.com/prowdsponsor/esqueleto/blob/master/test/Test.hs
 * https://github.com/m4dc4p/haskelldb/blob/master/test/TestCases.hs
 * https://github.com/yesodweb/persistent/blob/master/persistent-test/SumTypeTest.hs

I couldn't find any tests for groundhog.

 * https://github.com/lykahb/groundhog

I also had a look at Javascript generators.  They take a similar adhoc,
one-off approach.

 * https://github.com/valderman/haste-compiler/tree/master/Tests
 * https://github.com/faylang/fay/tree/master/tests

Is this the best we can do in Haskell?  Certainly it seems hard to use a
QuickCheck/SmallCheck approach for this purpose.  Is there any way this kind
of testing can be automated or made more robust?

Thanks,

Tom