Remove liquid Haskell result files

[meck]

These files get rewritten when the tests are run and dirties the repo.

[lorenzo]

makes sense to me

[meck]

It seems some tests for liquid Haskell depended on these files by reordering the tests this ensures they are present at first run of tests. Also added a check for the executable

[jhrcek]

I'm not sure if it's ok that these files were removed.
After I finally managed to install liquidhaskell v 0.8.2.4 I'm getting these failures when running make test with master:

      test/unit/LiquidSpec.hs:38: 
      1) Liquid, liquid haskell plugin, runs the liquid haskell exe
           predicate failed on: ""
    
      test/unit/LiquidSpec.hs:52: 
      2) Liquid, liquid haskell plugin, reads errors from json file
           uncaught exception: IOException of type NoSuchThing (/home/jhrcek/Devel/github.com/jhrcek/haskell-ide-engine/test/testdata/liquid/.liquid/Evens.hs.json: openBinaryFile: does not exist (No such file or directory))
    
      test/unit/LiquidSpec.hs:91: 
      3) Liquid, liquid haskell plugin, reads types from vim.annot file
           uncaught exception: IOException of type NoSuchThing (/home/jhrcek/Devel/github.com/jhrcek/haskell-ide-engine/test/testdata/liquid/.liquid/Evens.hs.vim.annot: openFile: does not exist (No such file or directory))
    
      test/unit/LiquidSpec.hs:105: 
      4) Liquid, liquid haskell plugin, reads types from vim.annot file 2
           uncaught exception: IOException of type UserError (user error (Pattern match failure in do expression at test/unit/LiquidSpec.hs:108:7-13))

I think this should be reverted (except maybe for the findExecutable test, which is useful).
Seeing that i passed in CI, but it's failing for me locally means that either I'm doing something wrong, or CI might be caching some files that cause the tests to pass?

[meck]

Test 1 indicates msg here is empty, that should be the output of the liquid command.

What is which liquid ?

if I run liquid test/testdata/liquid/Evens.hs --json from the project dir manually I get the expected output:

RESULT
[{"start":{"line":9,"column":1},"stop":{"line":9,"column":8},"message":"Error: Liquid Type Mismatch\n  Inferred type\n    VV : {v : Int | v == (7 : int)}\n \n  not a subtype of Required type\n    VV : {VV : Int | VV mod 2 == 0}\n \n  In Context"}]

Test 3-4 fails since they depend on the products produced by test 1

[jhrcek]

@meck sorry for confusion. It turns out that even though I had liquid was installed and present on path, I was missing the z3 SMT solver package. After installing it, all the tests are passing! Thank you