[question] Would it be possible to make Giraffe.EndpointRouting case-sensitive?

[toraritte]

I've been obsessing on this question for a while now, so just curious if it could be done (even if it is probably not worth it).

The Endpoint Routing section in the docs states that

several existing [default] routing functions couldn't be ported to Giraffe.EndpointRouting and [ASP.NET Core routing] routes are case-insensitive by default.

but the RouteOptions.LowercaseUrls property in the Microsoft.AspNetCore.Routing namespace is supposed to toggle this behaviour.

Again, my .NET (let alone ASP.NET Core) understanding is limited, but every online search points to the above solution... Thank you for any clarification!

[64J0]

Hi @toraritte, thanks for creating this issue, I'll be taking a look at it this week.

[64J0]

Hello again @toraritte. I've been looking for the official .NET documentation and other sources on the web, and I did test this option that you mentioned with the EndpointRoutingApp sample from this repository. It didn't work for me. This was the code I was using, if you'd like to play with it (from samples/EndpointRoutingApp):

open System
open Microsoft.AspNetCore
open Microsoft.AspNetCore.Builder
open Microsoft.AspNetCore.Hosting
open Microsoft.AspNetCore.Http
open Microsoft.Extensions.DependencyInjection
open Microsoft.Extensions.Hosting
open Giraffe
open Giraffe.EndpointRouting

let handler1: HttpHandler =
    fun (_: HttpFunc) (ctx: HttpContext) -> ctx.WriteTextAsync "Hello World"

let handler2 (firstName: string, age: int) : HttpHandler =
    fun (_: HttpFunc) (ctx: HttpContext) ->
        sprintf "Hello %s, you are %i years old." firstName age |> ctx.WriteTextAsync

let handler3 (a: string, b: string, c: string, d: int) : HttpHandler =
    fun (_: HttpFunc) (ctx: HttpContext) -> sprintf "Hello %s %s %s %i" a b c d |> ctx.WriteTextAsync

let endpoints =
    [ subRoute
          "/foo"
          [ GET
                [ route "/bar" (text "aloha!")
                  route "/Bar" (text "Aloha!")
                  route "/BAR" (text "ALOHA!") ] ]
      GET
          [ route "/" (text "Hello World")
            routef "/%s/%i" handler2
            routef "/%s/%s/%s/%i" handler3 ]
      GET_HEAD
          [ route "/foo" (text "Bar")
            route "/x" (text "y")
            route "/abc" (text "def")
            route "/123" (text "456") ]
      // Not specifying a http verb means it will listen to all verbs
      subRoute "/sub" [ route "/test" handler1 ] ]

let notFoundHandler = "Not Found" |> text |> RequestErrors.notFound

let configureApp (appBuilder: IApplicationBuilder) =
    appBuilder.UseRouting().UseGiraffe(endpoints).UseGiraffe(notFoundHandler)

let configureServices (services: IServiceCollection) =
    services.AddRouting(fun ctx -> ctx.LowercaseUrls <- false).AddGiraffe()
    |> ignore

[<EntryPoint>]
let main args =
    let builder = WebApplication.CreateBuilder(args)
    configureServices builder.Services

    let app = builder.Build()

    if app.Environment.IsDevelopment() then
        app.UseDeveloperExceptionPage() |> ignore

    configureApp app
    app.Run()

    0

And was testing with:

curl localhost:5000/foo/bar

curl localhost:5000/foo/Bar

curl localhost:5000/foo/BAR

Any of these returned this exception:

fail: Microsoft.AspNetCore.Server.Kestrel[13]
      Connection id "0HN2KSIQ7O89J", Request id "0HN2KSIQ7O89J:00000001": An unhandled exception was thrown by the application.
      Microsoft.AspNetCore.Routing.Matching.AmbiguousMatchException: The request matched multiple endpoints. Matches: 
      
      HTTP: GET /foo/bar
      HTTP: GET /foo/Bar
      HTTP: GET /foo/BAR
         at Microsoft.AspNetCore.Routing.Matching.DefaultEndpointSelector.ReportAmbiguity(Span`1 candidateState)
         at Microsoft.AspNetCore.Routing.Matching.DefaultEndpointSelector.ProcessFinalCandidates(HttpContext httpContext, Span`1 candidateState)
         at Microsoft.AspNetCore.Routing.Matching.DefaultEndpointSelector.Select(HttpContext httpContext, Span`1 candidateState)
         at Microsoft.AspNetCore.Routing.Matching.DfaMatcher.MatchAsync(HttpContext httpContext)
         at Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware.Invoke(HttpContext httpContext)
         at Microsoft.AspNetCore.HostFiltering.HostFilteringMiddleware.Invoke(HttpContext context)
         at Microsoft.AspNetCore.Watch.BrowserRefresh.BrowserRefreshMiddleware.InvokeAsync(HttpContext context)
         at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.ProcessRequests[TContext](IHttpApplication`1 application)

[toraritte]

Thank you for taking the time looking into this and also for posting the sample code! I can't even name a valid use case for case-sensitive URL paths, but had to ask..:)