Weird runtime error with eq

[TheSeamau5]

So, I was testing the core String library with elm-check when suddenly I had a weird runtime error.

This is the code I was testing with:

module Test.String (tests) where

import String
import Char
import Check (..)
import Random (..)
import Random.Extra (..)
import Random.String (..)
import Random.Char (..)


consUnconsInverse : Char -> String -> Bool
consUnconsInverse char string =
  let nextString = String.cons char string
  in
    case String.uncons nextString of
      Nothing -> False
      Just (c, str) ->
        c == char && str == string

tests : List Property
tests =
  [ property2 "Consing and unconsing are inverse operations" consUnconsInverse unicode (rangeLengthWord 0 1000 unicode)
  ]

and when I try checking my test:

import Test.String as String
import Check (check)

import Text (plainText)

testResult =
  check String.tests

main =
  plainText testResult

I get a runtime error that seems to point to the eq function defined in Javascript

Chrome (latest) :

Cannot use 'in' operator to search for '0' in 饑


Open the developer console for more details.

Firefox Developer Edition (latest):

invalid 'in' operand y


Open the developer console for more details.

When I open the developer console, I'm immediately pointed to the eq function.

This is the moment right before the type error:

The bug happens due to a next if statement. It asks, if i in y except that the in operator only works on objects and somehow an actual string, in this case : 饑, has managed to sneak in as y.

I speculate that what is needed is a typeof check for y the same way that there is a typeof check for x cuz typeof "饑" === "object" yields false

[evancz]

Thank you for the comprehensive issue! Love issues like this :)

This should be fixed by 6f5fbb8.

[evancz]

Thank you for the comprehensive issue! Love issues like this :)

This should be fixed by 6f5fbb8.