Override produces broken Javascript with template

[davedawkins]

Description

I have a class hierarchy that implements IAspect<'C> and overrides the Attach method. The bottom-most class(ProjectSelection) is causing Fable to generate code that fails at runtime, making reference to a non-existent method. This is caught by the example program below, and printed.

I've trimmed this down from my application code. If I remove the <'C> templating parameter, the issue goes away. That may be useful in tracking the issue down.

Bad code in class ProjectSelection:

    "OverrideIssue.AspectBase`1.Attach2B595"(owner) {
        super["OverrideIssue.AspectBase`1.Attach1505"](owner); // Attach1505 is undefined
        toConsole(printf("ProjectSelection: attach to %A"))(owner);
    }

Repro code

module OverrideIssue

type IAspect<'C> =
    abstract Attach: 'C -> unit

[<AbstractClass>]
type AspectBase<'C>( ) =

    abstract Attach: 'C -> unit
    default this.Attach (owner): unit = 
        printfn "AspectBase: attach to %A" owner

    interface IAspect<'C> with
        member __.Attach (owner): unit = __.Attach(owner)

type SelectionAspect<'Container>( ) =
    inherit AspectBase<'Container>()

    override __.Attach(owner) = 
        base.Attach(owner)
        printfn "SelectionAspect: attach to %A" owner

type ProjectSelection() =
    inherit SelectionAspect<string>()

    override __.Attach(owner) = 
        base.Attach(owner)
        printfn "ProjectSelection: attach to %A" owner

try
    (new ProjectSelection()).Attach("root")
with
| x -> printfn "Error: %s" x.Message

Fable REPL URL

https://fable.io/repl/#?code=LYewJgrgNgpgBAeQG4wE6oJZhgSQM54QwBQxALgJ4AO8OAgnjQMZkA8A5AMIB8cAvMThC4AQwBGeMqhEs4dMmRkALAFxwucALS8IAOwxlSAbVZ0JUmWU5QRBbgF1y1eA2ZkAQrZgceACjgAlPykwqLm0rLyikyq6pxaOvqGodgAZiLQZHBkShh4AHRRynC+IADuumgBanoG-HCCocJUmLpkqbpwAESuMCyeeDBqIgrFZCBwAKR0XXDllaghwhhtaOlMtL0sPrxlBkqNTXDAMMBiaHAA+peFozEl81U1SfXXt9FKpRVVpJQ0cABlGCwFgYEC6LZsLjgxQrNDcfxBAShFZKNB1SEDbzQtoiOGoBEBJZCEAodBYeBvIoxL4LJENI5CMRed7KWk-RlwFordqdLpAkFkMEQxh9MjDO5KbITaazR6LJz-AAKqBAACsxQKxcLfEjDnBUeislrQeDIaxJK0AOaE4lzMmYbBXG7Uz7y+n60LMwasmnuz3NVq87oq9Wa4Ha8ESj7SqYzObfBVSCj63yVMpwUMalgmoXg3UBX2fLqqkBkLpEvY5YgAHzgAA8Elygx1ugBRdAgVBqSZ4Wb1-IAWRgBBEVpgQA&html=Q&css=Q

Expected output

AspectBase: attach to root
SelectionAspect: attach to root
ProjectSelection: attach to root

Actual output

Error: super.OverrideIssue.AspectBase`1.Attach1505 is not a function

Related information

• Fable version: dotnet fable --version 4.20.0
• Operating system MacOS

[MangelMaxime]

Like you pointed out, I suppose the line:

super["Examples.AspectBase`1.Attach1505"](owner);

should be generated to:

super["Examples.AspectBase`1.Attach2B595"](owner);

[davedawkins]

I think so, yes