go get github.com/golang/mock/gomock
go get github.com/golang/mock/mockgen

package hellomock

type Talker interface {
  SayHello(word string)(response string)
}

package hellomock

import "fmt"

type Person struct{
 name string
}

func NewPerson(name string)*Person{
 return &Person{
   name:name,
 }
}


func (p *Person)SayHello(name string)(word string) {
 return fmt.Sprintf("Hello %s, welcome come to our company, my name is %s",name,p.name)  
}

package hellomock

type Company struct {
 Usher Talker
}

func NewCompany(t Talker) *Company{
 return &Company{
  Usher:t,
 }
}

func ( c *Company) Meeting(gusetName string)string{
 return c.Usher.SayHello(gusetName)
}

package hellomock

import "testing"

func TestCompany_Meeting(t *testing.T) {
  person := NewPerson("王尼美")
  company := NewCompany(person)
  t.Log(company.Meeting("王尼瑪"))
}

/usr/local/go/bin/go test -v hellomock -run ^TestCompany_Meeting$

  company_test.go:8: Hello 王尼瑪, welcome come to our company, my name is 王尼美

ok   hellomock  0.013s

// Automatically generated by MockGen. DO NOT EDIT!
// Source: hellomock.go

package mock_hellomock

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

// MockTalker is a mock of Talker interface
type MockTalker struct {
  ctrl   *gomock.Controller
  recorder *MockTalkerMockRecorder
}

// MockTalkerMockRecorder is the mock recorder for MockTalker
type MockTalkerMockRecorder struct {
  mock *MockTalker
}

// NewMockTalker creates a new mock instance
func NewMockTalker(ctrl *gomock.Controller) *MockTalker {
  mock := &MockTalker{ctrl: ctrl}
  mock.recorder = &MockTalkerMockRecorder{mock}
  return mock
}

// EXPECT returns an object that allows the caller to indicate expected use
func (_m *MockTalker) EXPECT() *MockTalkerMockRecorder {
  return _m.recorder
}

// SayHello mocks base method
func (_m *MockTalker) SayHello(name string) string {
  ret := _m.ctrl.Call(_m, "SayHello", name)
  ret0, _ := ret[0].(string)
  return ret0
}

// SayHello indicates an expected call of SayHello
func (_mr *MockTalkerMockRecorder) SayHello(arg0 interface{}) *gomock.Call {
  return _mr.mock.ctrl.RecordCall(_mr.mock, "SayHello", arg0)
}

func TestCompany_Meeting2(t *testing.T) {
  ctl := gomock.NewController(t)
  mock_talker := mock_hellomock.NewMockTalker(ctl)
  mock_talker.EXPECT().SayHello(gomock.Eq("王尼瑪")).Return("這是自定義的返回值，可以是任意類(lèi)型。")

  company := NewCompany(mock_talker)
  t.Log(company.Meeting("王尼瑪"))
  //t.Log(company.Meeting("張全蛋"))
}

/usr/local/go/bin/go test -v hellomock -run ^TestCompany_Meeting2$
  company_test.go:21: 這是自定義的返回值，可以是任意類(lèi)型。
ok   hellomock  0.015s

/usr/local/go/bin/go test -v hellomock -run ^TestCompany_Meeting2$
  controller.go:113: no matching expected call: *mock_hellomock.MockTalker.SayHello([張全蛋])
exit status 1
FAIL  hellomock  0.007s