spruce/internal/cmd/version.go

package cmd

import (
	"flag"
	"fmt"
	"strings"
)

type VersionCommand struct {
	*flag.FlagSet
	summary       string
	fullVersion   bool
	binaryVersion string
	buildTime     string
	goVersion     string
	gitCommit     string
}

func NewVersionCommand(binaryVersion, buildTime, goVersion, gitCommit string) *VersionCommand {
	vc := VersionCommand{
		FlagSet:       flag.NewFlagSet("version", flag.ExitOnError),
		binaryVersion: binaryVersion,
		buildTime:     buildTime,
		goVersion:     goVersion,
		gitCommit:     gitCommit,
		summary:       "Print the application's build information.",
	}

	vc.BoolVar(&vc.fullVersion, "full", false, "prints the full build information")

	vc.Usage = usageFunc(vc.Name(), vc.summary, vc.FlagSet)

	return &vc
}

func (v *VersionCommand) Run() error {
	var b strings.Builder
	if v.fullVersion {
		fmt.Fprintf(&b, "Spruce\n  Version: %s\n  Git commit: %s\n  Go version: %s\n  Build date: %s\n", v.binaryVersion, v.gitCommit, v.goVersion, v.buildTime)
	} else {
		fmt.Fprintln(&b, v.binaryVersion)
	}

	fmt.Print(b.String())
	return nil
}