next semver from git tag

nextver.go

package main

import (
	"fmt"
	"os"

	"github.com/Masterminds/semver/v3"
	"github.com/go-git/go-git/v5"
	"github.com/go-git/go-git/v5/plumbing"
)

func main() {
	wd, err := os.Getwd()
	if err != nil {
		fatal(err)
	}

	tag := latestTag(wd)
	v := incMinor(tag, "v")

	fmt.Println(v)
}

func incMinor(v string, prefix string) string {
	sv, err := semver.NewVersion(v)
	if err != nil {
		fatal(err)
	}

	return fmt.Sprintf("%s%s", prefix, sv.IncMinor())
}

func latestTag(wd string) string {
	repo, err := git.PlainOpen(wd)
	if err != nil {
		fatal(err)
	}

	iter, err := repo.Tags()
	if err != nil {
		fatal(err)
	}

	tags := make([]string, 0)
	iter.ForEach(func(ref *plumbing.Reference) error {
		tags = append(tags, ref.Name().Short())
		return nil
	})

	if len(tags) == 0 {
		return "0.0.0"
	}

	return tags[len(tags)-1]
}

func fatal(err error) {
	fmt.Println(err)
	os.Exit(1)
}