dikderoy/tagrelease

package tagrelease

import (
    "os/exec"
    "regexp"
    "strconv"
    "strings"

    log "github.com/sirupsen/logrus"
)

type GitAdapter struct {
}

// Describe executes and returns output from `git describe --tags`
func (git *GitAdapter) Describe() (o string) {
    bo, err := exec.Command("git", "describe", "--tags").Output()
    if err != nil {
        log.WithError(err).Debug("no output from describe")
        o = "0.0.0"
    } else {
        o = strings.TrimSpace(string(bo))
    }
    log.WithField("out", o).Debug("git describe output")
    return o
}

var reGitDescription = regexp.MustCompile(
    `^(v?(?P<major>\d+).(?P<minor>\d+)(.(?P<patch>\d+))?)(-(?P<diff>\d+)-(?P<ref>[0-9A-Za-z]+))?$`,
)

func (git *GitAdapter) evaluate(desc string) *Version {
    matches := reGitDescription.FindAllStringSubmatch(desc, -1)
    log.WithField("matches", matches).Debug("matches")
    if matches == nil {
        return &Version{}
    }

    var major, minor, patch, diff int
    major, _ = strconv.Atoi(matches[0][2])
    minor, _ = strconv.Atoi(matches[0][3])
    if matches[0][4] != "" { // we need to know if a patch is not defined
        patch, _ = strconv.Atoi(matches[0][5])
    } else {
        patch = -1
    }
    diff, _ = strconv.Atoi(matches[0][7]) // will return 0 on error (we are okay with that)

    return &Version{
        Major: major,
        Minor: minor,
        Patch: patch,
        Diff:  diff,
        Rev:   matches[0][8], // empty value is "" which is exactly what we need
    }
}

// Version calls Describe and then evaluate results to populate Version struct
func (git *GitAdapter) Version() *Version {
    return git.evaluate(git.Describe())
}

// Revision executes and returns output from `git rev-parse HEAD`
func (git *GitAdapter) Revision() (o string, err error) {
    bo, err := exec.Command("git", "rev-parse", "HEAD").Output()
    if err != nil {
        return "", err
    }
    o = string(bo)
    log.WithField("out", o).Debug("git rev-parse HEAD output")
    return strings.TrimSpace(o), nil
}

// Branch executes and returns output from `git rev-parse --abbrev-ref HEAD`
func (git *GitAdapter) Branch() (o string, err error) {
    bo, err := exec.Command("git", "rev-parse", "--abbrev-ref", "HEAD").Output()
    if err != nil {
        return "", err
    }
    o = string(bo)
    log.WithField("out", o).Debug("git rev-parse --abbrev-ref HEAD output")
    return strings.TrimSpace(o), nil
}