Add --version flag (#276)

* Add --version flags

* Update goreleaser for updating Hub version

* Fix linter warning

* Move version management in common package

* Add common package tests

* Fix linter warning

* Add commit into version informations

* Set commit in ldflags

* Changelog URL is based on dev version

* Update version template

* Use short commit in version information

.goreleaser.yml

@@ -2,7 +2,9 @@ before:
   hooks:
   - go mod download
 builds:
--
+- <<: &build_defaults
+    ldflags:
+      - -s -w -X github.com/dunglas/mercure/common.version={{ .Version }} -X github.com/dunglas/mercure/common.commit={{ .ShortCommit }} -X github.com/dunglas/mercure/common.buildDate={{ .Date }}
   env:
     - CGO_ENABLED=0
   goos:

cmd/root.go

@@ -1,8 +1,11 @@
 package cmd
 
 import (
+	"fmt"
+
 	log "github.com/sirupsen/logrus"
 
+	"github.com/dunglas/mercure/common"
 	"github.com/dunglas/mercure/hub"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
@@ -37,4 +40,10 @@ func init() { //nolint:gochecknoinits
 	})
 	fs := rootCmd.Flags()
 	hub.SetFlags(fs, v)
+
+	appVersion := common.AppVersion
+	rootCmd.Version = appVersion.Shortline()
+
+	versionTemplate := fmt.Sprintf("Mercure.rocks Hub version %s\n%s\n", rootCmd.Version, appVersion.ChangelogURL())
+	rootCmd.SetVersionTemplate(versionTemplate)
 }

common/version.go

@@ -0,0 +1,61 @@
+package common
+
+import (
+	"fmt"
+	"runtime/debug"
+	"strings"
+)
+
+type AppVersionInfo struct {
+	Version   string
+	BuildDate string
+	Commit    string
+}
+
+var AppVersion AppVersionInfo //nolint:gochecknoglobals
+
+// these variables are dynamically set at build.
+var version = "dev"
+var buildDate = "" //nolint:gochecknoglobals
+var commit = ""    //nolint:gochecknoglobals
+
+func (v *AppVersionInfo) Shortline() string {
+	shortline := v.Version
+
+	if v.Commit != "" {
+		shortline += fmt.Sprintf(", commit %s", v.Commit)
+	}
+
+	if v.BuildDate != "" {
+		shortline += fmt.Sprintf(", built at %s", v.BuildDate)
+	}
+
+	return shortline
+}
+
+func (v *AppVersionInfo) ChangelogURL() string {
+	path := "https://github.com/dunglas/mercure"
+
+	if v.Version == "dev" {
+		return fmt.Sprintf("%s/releases/latest", path)
+	}
+
+	return fmt.Sprintf("%s/releases/tag/v%s", path, strings.TrimPrefix(v.Version, "v"))
+}
+
+func init() { //nolint:gochecknoinits
+	if version == "dev" {
+		info, ok := debug.ReadBuildInfo()
+		if ok && info.Main.Version != "(devel)" {
+			version = info.Main.Version
+		}
+	}
+
+	version = strings.TrimPrefix(version, "v")
+
+	AppVersion = AppVersionInfo{
+		Version:   version,
+		BuildDate: buildDate,
+		Commit:    commit,
+	}
+}

common/version_test.go

@@ -0,0 +1,50 @@
+package common
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestVersionInfo(t *testing.T) {
+	v := AppVersionInfo{
+		Version:   "dev",
+		BuildDate: "",
+	}
+
+	assert.Equal(t, v.Shortline(), "dev")
+	assert.Equal(t, v.ChangelogURL(), "https://github.com/dunglas/mercure/releases/latest")
+}
+
+func TestVersionInfoWithBuildDate(t *testing.T) {
+	v := AppVersionInfo{
+		Version:   "1.0.0",
+		BuildDate: "2020-05-03T18:42:44Z",
+		Commit:    "",
+	}
+
+	assert.Equal(t, v.Shortline(), "1.0.0, built at 2020-05-03T18:42:44Z")
+	assert.Equal(t, v.ChangelogURL(), "https://github.com/dunglas/mercure/releases/tag/v1.0.0")
+}
+
+func TestVersionInfoWithCommit(t *testing.T) {
+	v := AppVersionInfo{
+		Version:   "1.0.0",
+		BuildDate: "",
+		Commit:    "96ee2b9",
+	}
+
+	assert.Equal(t, v.Shortline(), "1.0.0, commit 96ee2b9")
+	assert.Equal(t, v.ChangelogURL(), "https://github.com/dunglas/mercure/releases/tag/v1.0.0")
+}
+
+func TestVersionInfoWithBuildDateAndCommit(t *testing.T) {
+	v := AppVersionInfo{
+		Version:   "1.0.0",
+		BuildDate: "2020-05-03T18:42:44Z",
+		Commit:    "96ee2b9",
+	}
+
+	assert.Equal(t, v.Shortline(), "1.0.0, commit 96ee2b9, built at 2020-05-03T18:42:44Z")
+	assert.Equal(t, v.ChangelogURL(), "https://github.com/dunglas/mercure/releases/tag/v1.0.0")
+}