go单元测试

testing模块

• 测试代码放在当前包以_test.go结尾的文件中
• 测试函数以Test为名称前缀
• 测试命令（go test）
• 正常编译操作（go build/install）会忽略测试文件

单例模式举例

singleton.go

package singleton

import (
        "sync"
)

type Singleton struct{}

var (
        singleton *Singleton
        once      sync.Once
)

func GetInstance() *Singleton {
        once.Do(func() {
                singleton = &Singleton{}
        })
        return singleton
}

singleton_test.go

package singleton

import "testing"

func TestSingleton(t *testing.T) {
        ins1 := GetInstance()
        ins2 := GetInstance()
        if ins1 != ins2 {
                t.Fatal("instance is not equal")
        }
}

终端执行go test，会执行singleton_test.go里面写的测试用例

D:\project\src\go_dev\design_pattern\singleton>go test
PASS
ok      go_dev/design_pattern/singleton 0.346s

查看测试代码覆盖率

go test -coverprofile=c.out
go tool cover -html=c.out

输出

D:\project\src\go_dev\design_pattern\singleton>go test -coverprofile=c.out
PASS
coverage: 100.0% of statements
ok      go_dev/design_pattern/singleton 0.324s

性能测试(_test.go)

func BenchSingleton(b *testing.B) {
        ins1 := GetInstance()
        ins2 := GetInstance()
        for i := 0; i < b.N; i++ {
                if ins1 != ins2 {
                        b.Fatal("instance is not equal")
                }
        }
}

执行

go test -bench .

分析性能

D:\project\src\go_dev\design_pattern\singleton>go test -bench . -cpuprofile cpu.out
D:\project\src\go_dev\design_pattern\singleton>go tool pprof cpu.out
Type: cpu
Time: Aug 23, 2018 at 11:33am (CST)
Duration: 200ms, Total samples = 0
Entering interactive mode (type "help" for commands, "o" for options)
(pprof) web