Is it reasonable to verify args number match using reflect.TypeOf?

[reminia]

Go mock is using reflect.typeOf(method).NumIn() to verify method's args number match. See the code:

mock/gomock/call.go

Line 119 in fcaca4a

if c.methodType.NumIn() != ft.NumIn() {

It's not reasonable if the mocked method signature contains varargs. Coz in real method call, people would like to pass in
fixed number of args that will result in a different number error during go test. NumIn is static and fixed based on the method signature no matter how many args passed in. See below:

package main

import (
	"fmt"
	"reflect"
)

func f(a string, as ...string) {
	var tpe = reflect.TypeOf(f)
	fmt.Println("NumIn", tpe.NumIn())
}
func main() {
	// always print 2
	f("a")
	f("a", "b")
	f("a", "b", "c")
}

Maybe it should be verified by len(call.args) not through reflect.
Related issue #94