目录

什么是 mock

变量打桩

接口方法/Redis

函数/方法打桩

包函数

成员方法

MySQL

sqlmock

sqlite mock gorm

http mock

源码地址

单测基础

什么是 mock

       单元测试,顾名思义对某个单元函数进行测试,被测函数本身中用到的变量、函数、资源不应被测试代码依赖,所谓 mock,就是想办法通过 “虚拟” 代码替换掉依赖的方法和资源,一般需要 mock 掉以下依赖:

变量 函数/方法 MySQL Redis http 调用

变量打桩

有时我们的代码里依赖一个全局变量,测试方法根据全局变量的不同值执行不同的逻辑,那么可以用 gostub 对变量进行打桩。

 global.go:

package main

var size = 5

func Size() int {

if size > 10 {

return 10

}

return size

}

package main

import (

"testing"

"github.com/agiledragon/gomonkey/v2"

"github.com/prashantv/gostub"

)

func TestSizeStub(t *testing.T) {

tests := []struct {

name string

want int

f func() *gostub.Stubs

}{

{name: "size > 10", want: 10, f: func() *gostub.Stubs {

return gostub.Stub(&size, 11)

}},

{name: "size <= 10", want: 3, f: func() *gostub.Stubs {

return gostub.Stub(&size, 3)

}},

}

for _, tt := range tests {

t.Run(tt.name, func(t *testing.T) {

stub := tt.f()

if got := Size(); got != tt.want {

t.Errorf("Size() = %v, want %v", got, tt.want)

}

stub.Reset()

})

}

}

func TestSizeMonkey(t *testing.T) {

tests := []struct {

name string

want int

f func() *gomonkey.Patches

}{

{name: "size > 10", want: 10, f: func() *gomonkey.Patches {

return gomonkey.ApplyGlobalVar(&size, 11)

}},

{name: "size <= 10", want: 3, f: func() *gomonkey.Patches {

return gomonkey.ApplyGlobalVar(&size, 3)

}},

}

for _, tt := range tests {

t.Run(tt.name, func(t *testing.T) {

stub := tt.f()

if got := Size(); got != tt.want {

t.Errorf("Size() = %v, want %v", got, tt.want)

}

stub.Reset()

})

}

}

$ go test -v -cover

=== RUN TestSize

=== RUN TestSize/size_>_10

=== RUN TestSize/size_<=_10

--- PASS: TestSize (0.00s)

--- PASS: TestSize/size_>_10 (0.00s)

--- PASS: TestSize/size_<=_10 (0.00s)

PASS

coverage: 100.0% of statements

接口方法/Redis

首先 Go 语言推荐的是面向接口编程,所以官方提供并推荐使用  gomock  对依赖的方法进行 mock,前提是依赖的方法是通过抽象接口实现的,gomock 执行过程如下:

使用mockgen为你想要mock的接口生成一个mock。 在你的测试代码中,创建一个gomock.Controller实例并把它作为参数传递给mock对象的构造函数来创建一个mock对象。 调用EXPECT()为你的mock对象设置各种期望和返回值。 调用mock控制器的Finish()以验证mock的期望行为。

gomock 常用方法:

类型 用法 作用 参数 gomock.Any(v) 匹配任何类型 gomock.Eq(v) 匹配使用反射 reflect.DeepEqual 与 v 相等的值 gomock.Not(v) v 不是 Matcher 时,匹配使用反射 reflect.DeepEqual 与 v 不相等的值;v 是 Matcher 时,匹配和 Macher 不匹配的值(Matcher) gomock.Nil() 匹配等于 nil 的值 返回 Return() mock 方法返回值 Do(func) 传入的 func 在 mock 真正被调用时自动执行,忽略 Return,比如:对调用方法的参数进行校验 DoAndReturn(func) 传入的 func 在 mock 真正被调用时自动执行,对应 func 返回值作为 mock 方法返回值 调用次数 AnyTimes(n int) mock 方法可以被调用任意次数,一次不调用也不会失败(这里大家可以自检一下各自的单测代码,用这个方法的单测可能并没有按照预期运行) Times() mock 方法被调用次数,次数不相等运行失败 MaxTimes(n int) mock 方法被调用次数,大于规定次数运行失败 MinTimes(n int) mock 方法被调用次数,小于规定次数运行失败 调用排序 gomock.InOrder( first.EXPECT.Func().Return(), second.EXPECT.Func().Return(), thrid.EXPECT.Func().Return(), ) 规定多个 mock 方法的调用顺序,顺序不符运行失败 first := rc.EXPECT().DoFucn() second := rc.EXPECT().DoFunc().After(first) 规定多个 mock 方法的先后依赖关系,顺序不符运行失败

首先通过 mockgen 生成 Redis Client 的 mock 代码:

$ go get -u github.com/golang/mock/gomock

$ go install github.com/golang/mock/mockgen

本地interface:

mockgen[go run -mod=mod github.com/golang/mock/mockgen -package mock] -source ~/go/pkg/mod/github.com/opentracing/opentracing-go\@v1.2.0/tracer.go -destination ./opentracing/tracer.go Tracer

远端interface:

go run -mod=mod github.com/golang/mock/mockgen -package redis -destination ./mock/redis/redis.go github.com/go-redis/redis/v8 Cmdable

redis.go:

package main

import (

"context"

"github.com/go-redis/redis/v8"

)

func handleRedis(c redis.Cmdable) (string, error) {

return c.Get(context.Background(), "redis").Result()

}

func conn() *redis.Client {

return redis.NewClient(&redis.Options{Addr: "127.0.0.1:6379"})

}

package main

import (

"testing"

"github.com/go-redis/redis/v8"

"github.com/golang/mock/gomock"

)

func Test_handleRedis(t *testing.T) {

ctl := gomock.NewController(t)

defer ctl.Finish()

c := NewMockCmdable(ctl)

c.EXPECT().Get(gomock.Any(), gomock.Any()).Times(1).Return(redis.NewStringResult("redis", nil))

handleRedis(c)

}

函数/方法打桩

假如我们依赖的其他人写的方法,并不是通过接口实现的,无法使用 gomock 时,可以用 gomonkey 进行打桩

包函数

常用函数:

gomonkey.ApplyFunc():单个包函数打桩 gomonkey.ApplyFuncSeq():连续多个包函数打桩

func.go

package main

func A() int {

return B()

}

func AA() int {

return B() + B()

}

func B() int {

return 0

}

package main

import (

"testing"

"github.com/agiledragon/gomonkey/v2"

"github.com/stretchr/testify/assert"

)

// TestA 函数,单次打桩

func TestA(t *testing.T) {

patch := gomonkey.ApplyFunc(B, func() int {

return 1

})

defer patch.Reset()

assert.Equal(t, 1, A())

}

// TestAA 函数,连续打桩

func TestAA(t *testing.T) {

patch := gomonkey.ApplyFuncSeq(B, []gomonkey.OutputCell{

{Values: gomonkey.Params{1}},

{Values: gomonkey.Params{2}},

})

defer patch.Reset()

assert.Equal(t, 3, AA())

}

成员方法

常用函数:

gomonkey.ApplyMethod():单个公有成员方法打桩 patch.ApplyPrivateMethod():单个私有成员方法打桩 patch.ApplyMethodSeq():连续多个公有成员方法打桩 gomonkey.ApplyFuncSeq():连续多个私有成员方法打桩

method.go

package main

type S struct{}

func (s *S) A() int {

return s.B() + s.b()

}

func (s *S) AA() int {

return s.B() + s.b() + s.B() + s.b()

}

func (s *S) B() int {

return 0

}

func (s *S) b() int {

return 0

}

package main

import (

"reflect"

"testing"

"github.com/agiledragon/gomonkey/v2"

"github.com/stretchr/testify/assert"

)

// TestS_AA 成员方法单个打桩

func TestS_A(t *testing.T) {

s := &S{}

// 公共成员方法

patch := gomonkey.ApplyMethod(reflect.TypeOf(s), "B", func(_ *S) int {

return 1

})

// 私有成员方法

patch.ApplyPrivateMethod(reflect.TypeOf(s), "b", func(_ *S) int {

return 2

})

defer patch.Reset()

assert.Equal(t, 3, s.A())

}

// TestS_AA 成员方法连续打桩

func TestS_AA(t *testing.T) {

s := &S{}

// 私有成员方法

patch := gomonkey.ApplyFuncSeq((*S).b, []gomonkey.OutputCell{

{Values: gomonkey.Params{1}},

{Values: gomonkey.Params{2}},

})

// 公共成员方法

patch.ApplyMethodSeq(reflect.TypeOf(s), "B", []gomonkey.OutputCell{

{Values: gomonkey.Params{1}},

{Values: gomonkey.Params{2}},

})

defer patch.Reset()

assert.Equal(t, 6, s.AA())

}

MySQL

sqlmock

db.go

package main

import (

"database/sql"

"encoding/json"

"fmt"

_ "github.com/go-sql-driver/mysql"

"github.com/jmoiron/sqlx"

)

const dsn = "root:123456@tcp(127.0.0.1:3306)/test"

type Test struct {

ID int64 `json:"id" db:"id" gorm:"column:id"`

GoodsID int64 `json:"goodsID" db:"goods_id" gorm:"column:goods_id"`

Name string `json:"name" db:"name" gorm:"column:name"`

}

func (Test) TableName() string {

return "test"

}

func handle(db *sql.DB) (err error) {

tx, err := db.Begin()

if err != nil {

return

}

defer func() {

switch err {

case nil:

err = tx.Commit()

default:

tx.Rollback()

}

}()

rows, err := tx.Query("SELECT * from test where id > ?", 0)

if err != nil {

panic(err)

}

result := []Test{}

if err = sqlx.StructScan(rows, &result); err != nil {

panic(err)

}

b, err := json.Marshal(result)

if err != nil {

panic(err)

}

fmt.Println("sql:", string(b))

if _, err = tx.Exec("UPDATE test SET goods_id = goods_id + 1 where id = 2"); err != nil {

return

}

if _, err = tx.Exec("INSERT INTO test (goods_id, name) VALUES (?, ?)", 1, "1"); err != nil {

return

}

return

}

func main() {

db, err := sql.Open("mysql", dsn)

if err != nil {

panic(err)

}

defer db.Close()

if err = handle(db); err != nil {

panic(err)

}

}

package main

import (

"log"

"os"

"testing"

"time"

"github.com/DATA-DOG/go-sqlmock"

_ "github.com/go-sql-driver/mysql"

"github.com/stretchr/testify/assert"

)

func Test_handle(t *testing.T) {

db, mock, err := sqlmock.New()

if err != nil {

panic(err)

}

mock.ExpectBegin()

// (.+) 用于替代字段,可用于 select、order、group等

mock.ExpectQuery("SELECT (.+) from test where id > ?").WillReturnRows(sqlmock.NewRows([]string{"id", "goods_id", "name"}).AddRow(1, 1, "1"))

// sql前缀匹配

mock.ExpectExec("UPDATE test SET goods_id").WillReturnResult(sqlmock.NewResult(1, 1))

mock.ExpectExec("INSERT INTO test").WithArgs(1, "1").WillReturnResult(sqlmock.NewResult(1, 1))

mock.ExpectCommit()

if err = handle(db); err != nil {

panic(err)

}

if err = mock.ExpectationsWereMet(); err != nil {

panic(err)

}

}

sqlite mock gorm

如果遇到如下错误:

/usr/local/go16/pkg/tool/linux_amd64/link: running gcc failed: exit status 1

/usr/bin/ld: /tmp/go-link-866330658/000020.o(.text+0x74): unresolvable H��@�>H��FH��H��H��@�~�F�H��@�~H��8�H��H��0�FH��H��(�FH��H�� �FH��H���FH��H���FH��H��F�fD relocation against symbol `stderr@@GLIBC_2.2.5'

/usr/bin/ld: BFD version 2.20.51.0.2-5.34.el6 20100205 internal error, aborting at reloc.c line 443 in bfd_get_reloc_size

/usr/bin/ld: Please report this bug.

collect2: ld returned 1 exit status

更新 go env gcc 版本:

go env -w CC=/opt/compiler/gcc-8.2/bin/gcc

go env -w CXX=/opt/compiler/gcc-8.2/bin/g++

CC=/opt/compiler/gcc-8.2/bin/gcc CXX=/opt/compiler/gcc-8.2/bin/g++ go test -c -cover

db.go

package main

import (

"database/sql"

"encoding/json"

"fmt"

"gorm.io/driver/mysql"

"gorm.io/gorm"

)

const dsn = "root:123456@tcp(127.0.0.1:3306)/test"

type Test struct {

ID int64 `json:"id" db:"id" gorm:"column:id"`

GoodsID int64 `json:"goodsID" db:"goods_id" gorm:"column:goods_id"`

Name string `json:"name" db:"name" gorm:"column:name"`

}

func (Test) TableName() string {

return "test"

}

func main() {

orm, err := gorm.Open(mysql.Open(dsn))

if err != nil {

panic(err)

}

handleOrm(orm)

}

func handleOrm(orm *gorm.DB) {

var rows []Test

clause := func(db *gorm.DB) *gorm.DB {

return db.Where("id >= ?", 1)

}

err := clause(orm.Select("*")).Find(&rows).Error

if err != nil {

panic(err)

}

b, err := json.Marshal(rows)

if err != nil {

panic(err)

}

fmt.Println("gorm", string(b))

}

package main

import (

"log"

"os"

"testing"

"time"

"github.com/stretchr/testify/assert"

"gorm.io/driver/sqlite"

"gorm.io/gorm"

"gorm.io/gorm/logger"

)

func Test_handleOrm(t *testing.T) {

db := NewMemoryDB()

err := db.Migrator().CreateTable(&Test{})

assert.Nil(t, err)

handleOrm(db)

}

func NewMemoryDB() *gorm.DB {

var db *gorm.DB

var err error

newLogger := logger.New(

log.New(os.Stdout, "\r\n", log.LstdFlags), // io writer

logger.Config{

SlowThreshold: time.Second, // 慢 SQL 阈值

LogLevel: logger.Info, // Log level

Colorful: false, // 禁用彩色打印

},

)

dialector := sqlite.Open(":memory:?cache=shared")

if db, err = gorm.Open(dialector, &gorm.Config{

Logger: newLogger,

}); err != nil {

panic(err)

}

dba, err := db.DB()

dba.SetMaxOpenConns(1)

return db

}

func CloseMemoryDB(db *gorm.DB) {

sqlDB, _ := db.DB()

sqlDB.Close()

}

http mock

http.go

package main

import (

"fmt"

"net/http"

"time"

)

func Send() (err error) {

req, err := http.NewRequest(http.MethodGet, "https://127.0.0.1:8080", nil)

if err != nil {

return

}

client := &http.Client{

Timeout: time.Second,

}

resp, err := client.Do(req)

if err != nil {

return

}

defer resp.Body.Close()

if resp.StatusCode != http.StatusOK {

return fmt.Errorf("HTTP status is %d", resp.StatusCode)

}

return

}

package main

import (

"net/http"

"testing"

"github.com/jarcoal/httpmock"

"github.com/smartystreets/goconvey/convey"

"github.com/stretchr/testify/assert"

)

func TestSend(t *testing.T) {

convey.Convey("TestSend", t, func() {

convey.Convey("success", func() {

httpmock.Activate()

defer httpmock.DeactivateAndReset()

httpmock.RegisterResponder(http.MethodGet, "https://127.0.0.1:8080", httpmock.NewStringResponder(http.StatusOK, ""))

err := Send()

assert.Nil(t, err)

})

})

}