Golang에서 사용자 정의 유형을 단위 테스트하는 방법은 무엇입니까?

package mypackage

import "testing"

type MyType struct {
    value int
}

func TestSum(t *testing.T) {
    myType := MyType{1}
    if myType.Sum(2) != 3 {
        t.Error("Expected 3, got", myType.Sum(2))
    }
}

package mypackage

import (
    "testing"
    "github.com/golang/mock/gomock"
)

type MyInterface interface {
    DoSomething(value int)
}

func TestMyFunction(t *testing.T) {
    ctrl := gomock.NewController(t)
    defer ctrl.Finish()

    mockMyInterface := gomock.NewMockFrom(ctrl, "MyInterface")
    mockMyInterface.EXPECT().DoSomething(1).Return(nil)

    myFunction(mockMyInterface)
}

package mypackage

import (
    "testing"
)

type MyType struct {
    value int
}

func TestSum(t *testing.T) {
    myType := MyType{1}
    if assertEqual(myType.Sum(2), 3, t) {
        t.Error("Expected 3, got", myType.Sum(2))
    }
}

func assertEqual(actual, expected int, t *testing.T) bool {
    if actual != expected {
        t.Errorf("Expected %d, got %d", expected, actual)
    }
    return actual == expected
}