如何在go测试中检查日志/输出?

时间:2017-05-22 18:40:48

标签: testing go

我有这个函数在某些情况下记录错误:

func readByte(/*...*/){
    // ...
    if err != nil {
        fmt.Println("ERROR")
        log.Print("Couldn't read first byte")
        return
    }
    // ...
}

现在,在测试文件中,我想检查此函数的输出错误:

    c.Assert(OUTPUT, check.Matches, "teste")

如何访问日志?我试着放一个缓冲区,但它没有用。在不更改readByte函数代码的情况下捕获此日志的正确方法是什么?

1 个答案:

答案 0 :(得分:11)

例如,

readbyte_test.go

package main

import (
    "bytes"
    "fmt"
    "io"
    "log"
    "os"
    "testing"
)

func readByte( /*...*/ ) {
    // ...
    err := io.EOF // force an error
    if err != nil {
        fmt.Println("ERROR")
        log.Print("Couldn't read first byte")
        return
    }
    // ...
}

func TestReadByte(t *testing.T) {
    var buf bytes.Buffer
    log.SetOutput(&buf)
    defer func() {
        log.SetOutput(os.Stderr)
    }()
    readByte()
    t.Log(buf.String())
}

输出:

$ go test -v readbyte_test.go 
=== RUN   TestReadByte
ERROR
--- PASS: TestReadByte (0.00s)
    readbyte_test.go:30: 2017/05/22 16:41:00 Couldn't read first byte
PASS
ok      command-line-arguments  0.004s
$