IgnoreBase parameter of the static middleware counter-intuitive

[wdscxsj]

I understand what IgnoreBase does but can't convince myself that it should be the preferred option (as suggested in #1701). Could we have some documentation to justify its proper use? Thanks!

Here is an example to show why I think NOT using it feels more natural.

package main

import (
	"net/http"

	"github.com/labstack/echo/v4"
	"github.com/labstack/echo/v4/middleware"
)

func main() {
	e := echo.New()
	g1 := e.Group("/a")
	g1.Use(middleware.StaticWithConfig(middleware.StaticConfig{
		Root:       "public",
		IgnoreBase: true,
	}))
	g2 := e.Group("/b")
	g2.Use(middleware.Static("public"))
	if err := e.Start("127.0.0.1:9000"); err != http.ErrServerClosed {
		e.Logger.Fatal(err)
	}
}

File system structure:

public/
    index.html  # says: public
    a/
        index.html  # says: outer a
        a/
            index.html  # says: inner a

Test:

$ curl http://localhost:9000/a/  # OK
public
$ curl http://localhost:9000/a/a  # really?
public
$ curl http://localhost:9000/a/a/a
outer a
$ curl http://localhost:9000/a/a/a/a  # so long?
inner a
$ curl http://localhost:9000/b/  # OK
public
$ curl http://localhost:9000/b/a  # OK
outer a
$ curl http://localhost:9000/b/a/a  # OK
inner a