Fiber: 🚀 add 405 method not allowed handler

[kiyonlin]

Is your feature request related to a problem?
No

Describe the solution you'd like
Assuming that we have code like:

app := New()

app.Setting.HandleMethodNotAllowed = true

app.Post("/path", func(ctx *Ctx) {
    ctx.Send("hello")
})

app.Listen(3000)

and when we use the wrong method:

curl localhost:3000/path -I
> HTTP/1.1 405 Method Not Allowed
> Date: Sat, 20 Jun 2020 08:54:13 GMT
> Content-Type: text/plain; charset=utf-8
> Content-Length: 18

Additional context

• This feature will not bring breaking changes
• More friendlier to users
• Users can provide custom handler to handle 405

[Fenny]

We could add a boolean option in Settings named MethodNotAllowed bool and if set to true, instead of sending a 404 it will check the stack if it matches a different method and returns a 405 Method Not Allowed with the correct Allow header https://tools.ietf.org/html/rfc2616#section-10.4.6

[kiyonlin]

Yes, that’s my intention:smile:

[Fenny]

Fiber will respond with a 405 by default if another method is available on the same path.
This feature will be shipped in v1.12.1 next week, thank you for your suggestion 🥳

[Aoi-hosizora]

@Fenny I use 1.12.4, but I can't see the 405 response you described, here is my code:

func InitRoute(app *fiber.App) {
    v1 := app.Group("/v1")
    app.Get("/v2", func(ctx *fiber.Ctx) {}) // /v2
    v1.Get("/v2", func(ctx *fiber.Ctx) {}) // /v1/v2
}

app.Get (200)

app.Post (405 but 404)

v1.Get (200)

v1.Post (405 but 404)

[Fenny]

@Aoi-hosizora, thank you for your detailed bug report. Do you mind creating a separate issue regarding this matter?

[Aoi-hosizora]

@Fenny Yes, new issue: https://github.com/gofiber/fiber/issues/556