基本用法

• 測試文件名以_test結(jié)尾
• 函數(shù)名以Test開始

待測試代碼

// split.go
package split

import "strings"

func Split(str string, sep string) []string {
    var ret []string
    index := strings.Index(str, sep)
    for index >= 0 {
        ret = append(ret, str[:index])
        str = str[index+len(sep):]
        index  = strings.Index(str, sep)
    }
    ret = append(ret, str)
    return ret
}

測試代碼

// split_test.go
package split

import (
    "reflect"
    "testing"
)

func TestSplit(t *testing.T) {
    got := Split("a:b:c", ":")
    want := []string{"a", "b", "c"}
    if !reflect.DeepEqual(got, want) {
        t.Errorf("expected: %v, got: %v\n", want, got)
    }
}

到所在目錄執(zhí)行

go test -v

測試組

優(yōu)化多個測試用例的代碼

func TestSplitByGroup(t *testing.T) {
    type testCase struct {
        str string
        sep string
        want []string
    }

    testGroup := []testCase {
        {"babcbef", "b", []string{"", "a", "c", "ef"}},
        { "a:b:c", ":", []string{"a", "b", "c"}},
        {"abcef", "bc", []string{"a", "ef"}},
    }

    for _, tg := range testGroup {
        got := Split(tg.str, tg.sep)
        if !reflect.DeepEqual(got, tg.want) {
            t.Errorf("expected: %v, got: %v\n", tg.want, got)
        }
    }
}

子測試

用于區(qū)分測試組中，具體執(zhí)行了哪個測試用例

func TestSplit3(t *testing.T) {
    type testCase struct {
        str  string
        sep  string
        want []string
    }

    testGroup := map[string]testCase{
        "case1": {str: "babcbef", sep: "b", want: []string{"", "a", "c", "ef"}},
        "case2": {str: "a:b:c", sep: ":", want: []string{"a", "b", "c"}},
        "case3": {str: "abcef", sep: "bc", want: []string{"a", "ef1"}},
    }

    for name, tg := range testGroup {
        t.Run(name, func(t *testing.T) {
            got := Split(tg.str, tg.sep)
            if !reflect.DeepEqual(got, tg.want) {
                t.Errorf("expected: %#v, got: %#v\n", tg.want, got)
            }
        })
    }
}

測試結(jié)果可以看到是case3結(jié)果出錯了

image-20221119000527171

如果想跑某一個測試用例

go test -run=Split3/case1
go test -run=Split
// 如果run參數(shù)錯了，找不到測試用例，會warning
// testing: warning: no tests to run

測試覆蓋率

• 函數(shù)覆蓋率100%
• 代碼覆蓋著60%

簡單使用

go test -cover

image-20221119001017029

使用工具

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

image-20221119001337342

基準(zhǔn)測試

• 函數(shù)名以Benchmark開始
• 必須執(zhí)行b.N次

func BenchmarkSplit(b *testing.B) {
    for i := 0; i < b.N; i++ {
        Split("a:b:c", ":")
    }
}

運(yùn)行

go test -bench=Split
go test -bench .

image-20221119141057822

看內(nèi)存信息

go test -bench=Split -benchmem

image-20221119141221966

每次操作使用了三次內(nèi)存分配

還可以重置時間

b.ResetTimer()

Test Main

當(dāng)測試文件中有TestMain函數(shù)，執(zhí)行go test就會會調(diào)用TestMain，否則會創(chuàng)建一個默認(rèn)的TestMain；我們自定義TestMain時，需要手動調(diào)用m.Run()否則測試函數(shù)不會執(zhí)行

func TestMain(m *testing.M) {
    fmt.Println("before code...")
    retCode := m.Run()
    fmt.Println("retCode", retCode)
    fmt.Println("after code...")
    os.Exit(retCode)
}