validation - How to validate JSON with schema in Haskell? -

i want validate json schema. hjsonschema seemed choice new , supports latest draft. plotly json schema gives me valid responses.

i may misunderstanding here should not valid json

bad.json

{     "fjsdklj" : 5 } 

even though considered valid following code

module main  import           control.applicative import           data.aeson import           data.hashmap.strict (hashmap) import qualified data.hashmap.strict h import           data.monoid import qualified data.bytestring.lazy b import qualified data.jsonschema js import data.maybe  main :: io () main =     schemajson <- (fromjust . decode) <$> b.readfile "simple-schema.json"     bad <- (fromjust . decode) <$> b.readfile "bad.json"     let schemadata = js.rawschema {                         js._rsuri = nothing,                         js._rsdata = schemajson                         }     schema <- compileschema (js.schemagraph schemadata h.empty) schemadata     checkresults (js.validate schema bad)  compileschema :: js.schemagraph -> js.rawschema -> io (js.schema js.draft4failure) compileschema graph rs =   case js.compiledraft4 graph rs of     left failure -> error $ "not valid schema: " <> show failure     right schema -> return schema  checkresults :: [js.validationfailure js.draft4failure] -> io () checkresults [] = putstrln "just fine" checkresults x = putstrln $ "error: " ++ show x 

simple-schema.json plotly schema , bad.json snippet posted above.

it's nothing haskell.

your schema doesn't have required property @ top level empty json object acceptable.

also contains no "additionalproperties": false property not fit 1 of defined patterns ignored.

btw doubt whether it's valid draft4 json schema. passed validation of draft4 meta-schema syntax little bit different, maybe python-specific. you'd better run test suites came along hjsonscheme package see if works fine.