以编程方式获得golang覆盖

Question

go -cover或-coverprofile在运行go测试时非常出色，并且可以在html或纯文本中很好地显示。但有没有一个API来以编程方式访问它或处理文件？

Answer 1

你可以尝试axw/gocov，其中：

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

你可以看到像GoCov GUI的工具，以建立一个小的使用gocov.Statement在convert_statements(s []*gocov.Statement, offset int) GUI：

Answer 2

让我们假设我们想要获得一个项目的测试覆盖百分比（作为float64），我们从某个地方从git仓库动态获取并存储在当前文件夹下的“_repos/src”下。输入将是典型的“go get”格式的项目。我们需要执行“go test -cover”，并设置正确的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，以下代码可以实现这一目标。

// 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 
}