[alpha] Runtime exception with --debug when Json.Encode.null in init

[simonh1000]

Using Ubuntu 16.04, and 0.18 alpha.

The code below (initialising with null) fails to start and causes an exception, while using the commented out section (with string) works fine.

module Test exposing (main)

import Html exposing (..)
import Json.Encode as E exposing (Value)

-- MODEL

type alias Model =
    { gmap : Value
    }

init : (Model, Cmd Msg)
init =
    ( Model E.null, Cmd.none )
    -- ( Model (E.string "Dummy text"), Cmd.none )

-- UPDATE
type Msg
    = North

update : Msg -> Model -> (Model, Cmd Msg)
update message model =
    model ! []
-- VIEW

view : Model -> Html Msg
view model =
    text "hello world"

main =
  Html.program
    { init = init
    , update = update
    , view = view
    , subscriptions = always Sub.none
    }

[If the fix is not to test for null values, then note that in my code that originally ran into this bug, just fixing the init value to use Encode.string "dummy string" was not enough, as I got another null value being passed to init (which I have not tracked down yet) - see https://github.com/simonh1000/elm-google-maps-2]

[process-bot]

Thanks for the issue! Make sure it satisfies this checklist. My human colleagues will appreciate it!

Here is what to expect next, and if anyone wants to comment, keep these things in mind.

[evancz]

Thanks for the report, should be fixed if you get rid of elm-stuff/ and rebuild!