feat(smalltrip,multiplexer): form method multiplexer

smalltrip/multiplexer/request.go

@@ -0,0 +1,22 @@
+package multiplexer
+
+import (
+	"net/http"
+	"strings"
+)
+
+func WithFormMethod(mux Multiplexer, key string) Multiplexer {
+	return &formMethodMux{key: key, Multiplexer: mux}
+}
+
+type formMethodMux struct {
+	key string
+	Multiplexer
+}
+
+func (mux *formMethodMux) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if v := r.FormValue(mux.key); v != "" {
+		r.Method = strings.ToUpper(v)
+	}
+	mux.Multiplexer.ServeHTTP(w, r)
+}