Custom router gets stuck in a SetRoute loop on first navigation

[NickDarvey]

I'm having an issue with implementing a custom router where it setRoute is called infinitely.

let router : Router<Page, Model, Message> = {
  getEndPoint = fun m -> m.page
  setRoute = fun path ->
      match path.Trim('/').Split('/') with
      | [||]     -> Some <| Home
      | [|"c" |] -> Some <| Counter
      | _ -> None
      |> Option.map SetPage
  getRoute = function
      | Page.Home    -> "/"
      | Page.Counter -> "/c"
}

https://github.com/NickDarvey/bolero-custom-router/blob/0bfea305481d412cc4ab9f2ae25e2bd85f8c8c49/src/RoutingPlz.Client/Main.fs#L98-L111

Repro

1. Clone this repo
2. Run app
3. Click 'counter' link

Expected

Navigates to counter page via an invocation of setRoute.

Actual

setRoute is called infinitely.

System info

• The repro project a stripped down version of the bolero-app template.
• I (believe I) followed the steps in the docs to create my router.

This is at the top of the call stack:

Bolero.dll!<StartupCode$Bolero>.$Components.OnLocationChanged@146<RoutingPlz.Client.Main.Model, RoutingPlz.Client.Main.Message>.Invoke(Bolero.IRouter<RoutingPlz.Client.Main.Model, RoutingPlz.Client.Main.Message> router)

Bolero/src/Bolero/Components.fs

Lines 145 to 149 in 4b2e042

	member private this.OnLocationChanged (_: obj) (e: LocationChangedEventArgs) =
	this.Router |> Option.iter (fun router ->
	let uri = this.NavigationManager.ToBaseRelativePath(e.Location)
	let route = router.SetRoute uri
	Option.iter dispatch route)

[Tarmil]

Ah, I found the problem. In the custom router, getRoute actually needs to return relative paths, ie without the initial /. That's doubly wrong: it's not intuitive, and it contradicts the documentation! I'll fix it so that either absolute or relative paths can be used.

[NickDarvey]

Fantastic, thank you @Tarmil