Naming or shadowing issue with `arguments` field in record sent through port

[schpaa]

I want to send MyRecord through a port. But it fails with the console message:

TypeError: undefined is not an object (evaluating 'xs.ctor')

This is what I'm doing, javascript first:

app.ports.apiv1.subscribe(function(commandRecord) {
    console.log("app.ports.api... ",commandRecord)
})

in some port module I have defined the port:

port apiv1 : MyRecord -> Cmd a

where MyRecord is defined as:

type alias MyRecord =
    { command : String
    , arguments : List String
    }

somewhere in the view-function, this happens:

...
in
    flexDiv
        <| [ button [ onClick SendApiV1Message ] [ text "Send api message" ]

supported by my update-function:

...
case msg of
    SendApiV1Message ->
        let
            x : MyRecord
            x = { command = "Hello", arguments = [ "one", "tow", "three" ] }
        in
            model ! [ apiv1 x ]
...

To fix/bypass

If I change MyRecord and substitute the List String with a String, like this:

type alias MyRecord =
    { command : String
    , arguments : String
    }

there are no messages in the console, and the program works.

[schpaa]

Investigating further, this peculiar thing revealed itself to me:

Gives back arguments as undefined in the browser-console, all the other works.

type alias MyRecord =
    { command : String
    , arguments : String
    , extra : Int
    }

This one works, any shadowing happening with arguments here?

type alias MyRecord =
    { command : String
    , argumentodos : String
    , extra : Int
    }

[schpaa]

Investigating further, this peculiar thing revealed itself to me:

Gives back arguments as undefined in the browser-console, all the other works.

type alias MyRecord =
    { command : String
    , arguments : String
    , extra : Int
    }

This one works, any shadowing happening with arguments here?

type alias MyRecord =
    { command : String
    , argumentodos : String
    , extra : Int
    }

[jvoigtlaender]

Related to elm/compiler#994?

[jvoigtlaender]

Related to elm/compiler#994?

[schpaa]

Yes, it seems so. What should I do?

[schpaa]

Yes, it seems so. What should I do?

[jvoigtlaender]

I think: Open a new issue at the https://github.com/elm-lang/elm-compiler repository. Put an http://sscce.org/ into the first comment on that new issue.

If possible, try to capture the "old" case from elm/compiler#994 as well. (It seems that your problem is about outgoing ports, whereas the one originally reported there was about incoming ports. But the base problem, reserved JS names in stuff going through ports, seems to be the same. So it would be great if you could cover both, since the underlying bug for both might be the same. That probably means you would have to come up with two SSCCEs.)

[jvoigtlaender]

I think: Open a new issue at the https://github.com/elm-lang/elm-compiler repository. Put an http://sscce.org/ into the first comment on that new issue.

If possible, try to capture the "old" case from elm/compiler#994 as well. (It seems that your problem is about outgoing ports, whereas the one originally reported there was about incoming ports. But the base problem, reserved JS names in stuff going through ports, seems to be the same. So it would be great if you could cover both, since the underlying bug for both might be the same. That probably means you would have to come up with two SSCCEs.)

[evancz]

Tracking in elm/compiler#1685 now. This will make it easier to fix them all in one batch. Thank you for the report!

[evancz]

Tracking in elm/compiler#1685 now. This will make it easier to fix them all in one batch. Thank you for the report!