import(
    "github.com/stretchr/testify/assert"
    "testing"
)
func TestHelloTom(t *testing.T) {
    output := HelloTom()
    expectOutput := "Tom"
    assert.Equal(t, expectOutput, output)
}
func HelloTom() string {
    return "Tom"
}

// judgment.go
func JudgePassLine(score int16) bool {
    if score >= 60 {
        return true
    }
    else {
        return false
    }
}
// judgment_test.go
func TestJudgePassLineTrue(t *testing.T) {
    isPass := JudgeePassLine(70)
    assert.Equal(t, true, isPass)
}
func TestJudgePassLineFalse(t *testing.T) {
    isPass := JudgeePassLine(50)
    assert.Equal(t, false, isPass)
}
/*
 通過go test 命令測試覆蓋率
 go test judgment_test.go judgment.go --cover
*/

func ReadFirstLine() string {
    open, err := os.Open("log") // 打開一個文件
    defer open.Close()
    if err != nil {
        return ""
    }
    scanner := bufio.NewScanner(open) // 對每行進行遍歷
    for scanner.Scan() {
        return scanner.Text()
    }
    return ""
}
func ProcessFirstLine() string {
    line := ReadFirstLine()
    destLine := strings.ReplaceAll(line, "11", "00") // 替換11為00
    return destLine
}
func TestProcessFirstLine(t *testing.T) { // 執(zhí)行單元測試
    firstLine := ProcessFirstLine()
    assert.Equal(t, "line00", firstLine)
}

// 用函數(shù)A去替換函數(shù)B，B就是原函數(shù)，A就是打樁函數(shù)
func Patch(target, replacement interface{}) *PatchGuard {
    // target就是原函數(shù)，replacement就是打樁函數(shù)
    t := reflect.ValueOf(target)
    r := reflect.ValueOf(replacement)
    patchValue(t, r)
    return &PatchGuard{t, r}
}
func Unpatch(target interface{}) bool {
    // 保證了在測試結(jié)束之后需要把這個包卸載掉
    return unpatchValue(reflect.ValueOf(target))
}
func TestProcessFirstLineWithMock(t *testing.T) {
    monkey.Patch(ReadFirstLine, func() string {
        return "line110"
    })
    defer monkey.Unpatch(ReadFirstLine)
    line := ProcessFirstLine()
    assert.Equal(t, "line000", line)
}
// 通過patch對ReadFirstLine進行打樁mock，默認返回line110，通過defer卸載mock
// 這樣整個測試函數(shù)就擺脫了本地文件的束縛和依賴