以编程方式获取 golang 覆盖率

Question

go -cover 或 -coverprofile 在运行 go 测试时非常有用，并且可以很好地显示为 html 或纯文本。但是是否有 api 可以以编程方式访问它或处理文件？

Answer 1

你可以试试axw/gocov，其中：

• will run test with a -coverprofile argument
• 解析结果 (gocov/convert.go)

您可以看到像GoCov GUI 这样的工具在convert_statements(s []*gocov.Statement, offset int) 中使用gocov.Statement 来构建一个小型GUI：

Answer 2

让我们假设我们想要获得一个项目的测试覆盖率（作为 float64），我们从某个地方动态地从 git repo 获取，并存储在“_repos/src”下的当前文件夹中。输入将是典型的“go get”格式的项目。我们需要执行“go test -cover”，设置正确的 GOPATH 变量，解析输出，并提取测试覆盖率的实际百分比。使用当前的 Go 1.9 测试工具，下面的代码实现了这一点。

// ParseFloatPercent turns string with number% into float.
func ParseFloatPercent(s string, bitSize int) (f float64, err error) {
    i := strings.Index(s, "%")
    if i < 0 {
        return 0, fmt.Errorf("ParseFloatPercent: percentage sign not found")
    }
    f, err = strconv.ParseFloat(s[:i], bitSize)
    if err != nil {
        return 0, err
    }
    return f / 100, nil
}

// GetTestCoverage returns the tests code coverage as float
// we are assuming that project is a string
// in a standard "Go get" form, for example:
//     "github.com/apache/kafka"
// and, that you have cloned the repo into "_repos/src"
// of the current folder where your executable is running.
//
func GetTestCoverage(project string) (float64, error) {
    cmdArgs := append([]string{"test", "-cover"}, project)
    cmd := exec.Command("go", cmdArgs...)
    // get the file absolute path of our main executable
    dir, err := filepath.Abs(filepath.Dir(os.Args[0]))
    if err != nil {
        log.Println(err)
        return 0, err
    }
    // set the GOPATH for tests to work
    cmd.Env = os.Environ()
    cmd.Env = append(cmd.Env, "GOPATH="+dir+"/_repos/")

    var out []byte
    cmd.Stdin = nil
    out, err = cmd.Output()

    if err != nil {
        fmt.Println(err.Error())
        return 0, err
    }

    r := bufio.NewReader(bytes.NewReader(out))
    // first line from running "go test -cover" should be in a form
    // ok   <project>   6.554s  coverage: 64.9% of statements
    // split with /t and <space> characters
    line, _, err := r.ReadLine()

    if err != nil {
        fmt.Println(err.Error())
        return 0, err
    }

    parts := strings.Split(string(line), " ")
    if len(parts) < 6 {
        return 0, errors.New("go test -cover do not report coverage correctly")
    }
    if parts[0] != "ok" {
        return 0, errors.New("tests do not pass")
    }
    f, err := ParseFloatPercent(parts[3], 64)
    if err != nil {
        // the percentage parsing problem
        return 0, err
    }

    return f, nil
}