// A constructor for middleware
// that writes its own "tag" into the RW and does nothing else.
// Useful in checking if a chain is behaving in the right order.
func tagMiddleware(tag string) Constructor {
return func(h wctx.Handler) wctx.Handler {
return wctx.HandleFunc(func(c context.Context, w http.ResponseWriter, r *http.Request) {
w.Write([]byte(tag))
h.ServeHTTP(c, w, r)
})
}
}
// StripPrefix returns a handler that serves HTTP requests
// by removing the given prefix from the request URL's Path
// and invoking the handler h. StripPrefix handles a
// request for a path that doesn't begin with prefix by
// replying with an HTTP 404 not found error.
func StripPrefix(prefix string) func(wctx.Handler) wctx.Handler {
return func(h wctx.Handler) wctx.Handler {
if prefix == "" {
return h
}
return wctx.HandleFunc(func(c context.Context, w http.ResponseWriter, r *http.Request) {
if p := strings.TrimPrefix(r.URL.Path, prefix); len(p) < len(r.URL.Path) {
r.URL.Path = p
h.ServeHTTP(c, w, r)
}
// else {
// // problematic case
// NotFound(w, r)
// }
})
}
}
w.Write([]byte(tag))
h.ServeHTTP(c, w, r)
})
}
}
// Not recommended (https://golang.org/pkg/reflect/#Value.Pointer),
// but the best we can do.
func funcsEqual(f1, f2 interface{}) bool {
val1 := reflect.ValueOf(f1)
val2 := reflect.ValueOf(f2)
return val1.Pointer() == val2.Pointer()
}
var testApp = wctx.HandleFunc(func(c context.Context, w http.ResponseWriter, r *http.Request) {
w.Write([]byte("app\n"))
})
// Tests creating a new chain
func TestNew(t *testing.T) {
c1 := func(h wctx.Handler) wctx.Handler {
return nil
}
// c2 := func(h wctx.Handler) wctx.Handler {
// return wctx.StripPrefix("potato", nil)
// }
slice := []Constructor{c1, extra.StripPrefix("potato")}
chain := New(slice...)
assert.True(t, funcsEqual(chain.constructors[0], slice[0]))
// ThenFunc works identically to Then, but takes
// a HandlerFunc instead of a Handler.
//
// The following two statements are equivalent:
// c.Then(wctx.HandleFunc(fn))
// c.ThenFunc(fn)
//
// ThenFunc provides all the guarantees of Then.
func (c Chain) ThenFunc(fn wctx.HandleFunc) wctx.Handler {
if fn == nil {
return c.Then(nil)
}
return c.Then(wctx.HandleFunc(fn))
}