internal/git/alternates/alternates.go

package alternates

import (
	"fmt"
	"path/filepath"
	"strings"
)

// Env returns the alternate object directory environment variables.
func Env(repoPath, objectDirectory string, alternateObjectDirectories []string) []string {
	var env []string
	if objectDirectory != "" {
		env = append(env, fmt.Sprintf("GIT_OBJECT_DIRECTORY=%s", filepath.Join(repoPath, objectDirectory)))
	}

	if len(alternateObjectDirectories) > 0 {
		var dirsList []string

		for _, dir := range alternateObjectDirectories {
			dirsList = append(dirsList, filepath.Join(repoPath, dir))
		}

		env = append(env, fmt.Sprintf("GIT_ALTERNATE_OBJECT_DIRECTORIES=%s", strings.Join(dirsList, ":")))
	}

	return env
}