fix error output

Makefile

@@ -1,7 +1,7 @@
 .PHONY: *
 
 MAIN := .
-TEST := . ./internal
+TEST := ./cmd ./internal
 
 run:
 	go run $(MAIN)

cmd/root.go

@@ -0,0 +1,77 @@
+package cmd
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"runtime/debug"
+
+	"github.com/choffmeister/git-describe-semver/internal"
+	"github.com/go-git/go-git/v5"
+)
+
+func run(dir string, opts internal.GenerateVersionOptions) (*string, error) {
+	repo, err := git.PlainOpen(dir)
+	if err != nil {
+		return nil, fmt.Errorf("unable to open git repository: %v", err)
+	}
+	tagName, counter, headHash, err := internal.GitDescribe(*repo)
+	if err != nil {
+		return nil, fmt.Errorf("unable to describe commit: %v", err)
+	}
+	result, err := internal.GenerateVersion(*tagName, *counter, *headHash, opts)
+	if err != nil {
+		return nil, fmt.Errorf("unable to generate version: %v", err)
+	}
+	return result, nil
+}
+
+func Execute(version FullVersion) error {
+	fallbackFlag := flag.String("fallback", "", "The first version to fallback to should there be no tag")
+	dropPrefixFlag := flag.Bool("drop-prefix", false, "Drop prefix from output")
+	prereleaseSuffixFlag := flag.String("prerelease-suffix", "", "Suffix to add to prereleases")
+	formatFlag := flag.String("format", "", "Format of output")
+	flag.Parse()
+
+	dir, err := os.Getwd()
+	if err != nil {
+		return err
+	}
+	opts := internal.GenerateVersionOptions{
+		FallbackTagName:   *fallbackFlag,
+		DropTagNamePrefix: *dropPrefixFlag,
+		PrereleaseSuffix:  *prereleaseSuffixFlag,
+		Format:            *formatFlag,
+	}
+	result, err := run(dir, opts)
+	if err != nil {
+		return err
+	}
+	fmt.Println(*result)
+
+	return nil
+}
+
+type FullVersion struct {
+	Version string
+	Commit  string
+	Date    string
+	BuiltBy string
+}
+
+func (v FullVersion) ToString() string {
+	result := v.Version
+	if v.Commit != "" {
+		result = fmt.Sprintf("%s\ncommit: %s", result, v.Commit)
+	}
+	if v.Date != "" {
+		result = fmt.Sprintf("%s\nbuilt at: %s", result, v.Date)
+	}
+	if v.BuiltBy != "" {
+		result = fmt.Sprintf("%s\nbuilt by: %s", result, v.BuiltBy)
+	}
+	if info, ok := debug.ReadBuildInfo(); ok && info.Main.Sum != "" {
+		result = fmt.Sprintf("%s\nmodule version: %s, checksum: %s", result, info.Main.Version, info.Main.Sum)
+	}
+	return result
+}

main_test.go → cmd/root_test.go

@@ -1,4 +1,4 @@
-package main
+package cmd
 
 import (
 	"io/ioutil"
@@ -14,24 +14,24 @@ func TestRun(t *testing.T) {
 	assert := assert.New(t)
 	dir, _ := ioutil.TempDir("", "example")
 	author := object.Signature{Name: "Test", Email: "[email protected]"}
-	_, err := Run(dir, internal.GenerateVersionOptions{})
+	_, err := run(dir, internal.GenerateVersionOptions{})
 	assert.Error(err)
 
 	repo, _ := git.PlainInit(dir, false)
 	worktree, _ := repo.Worktree()
-	_, err = Run(dir, internal.GenerateVersionOptions{})
+	_, err = run(dir, internal.GenerateVersionOptions{})
 	assert.Error(err)
 
 	commit1, _ := worktree.Commit("first", &git.CommitOptions{Author: &author})
 	repo.CreateTag("invalid", commit1, nil)
-	_, err = Run(dir, internal.GenerateVersionOptions{})
+	_, err = run(dir, internal.GenerateVersionOptions{})
 	assert.Error(err)
 
 	commit2, _ := worktree.Commit("first", &git.CommitOptions{Author: &author})
 	repo.CreateTag("v1.0.0", commit2, nil)
 
 	commit3, _ := worktree.Commit("second", &git.CommitOptions{Author: &author})
-	result, err := Run(dir, internal.GenerateVersionOptions{})
+	result, err := run(dir, internal.GenerateVersionOptions{})
 	assert.NoError(err)
 	assert.Equal("v1.0.1-dev.1.g"+commit3.String()[0:7], *result)
 }

main.go

@@ -1,52 +1,23 @@
 package main
 
 import (
-	"flag"
 	"fmt"
-	"log"
 	"os"
 
-	"github.com/choffmeister/git-describe-semver/internal"
-	"github.com/go-git/go-git/v5"
+	"github.com/choffmeister/git-describe-semver/cmd"
 )
 
-// Run ...
-func Run(dir string, opts internal.GenerateVersionOptions) (*string, error) {
-	repo, err := git.PlainOpen(dir)
-	if err != nil {
-		return nil, fmt.Errorf("unable to open git repository: %v", err)
-	}
-	tagName, counter, headHash, err := internal.GitDescribe(*repo)
-	if err != nil {
-		return nil, fmt.Errorf("unable to describe commit: %v", err)
-	}
-	result, err := internal.GenerateVersion(*tagName, *counter, *headHash, opts)
-	if err != nil {
-		return nil, fmt.Errorf("unable to generate version: %v", err)
-	}
-	return result, nil
-}
+// nolint: gochecknoglobals
+var (
+	version = "dev"
+	commit  = ""
+	date    = ""
+	builtBy = ""
+)
 
 func main() {
-	fallbackFlag := flag.String("fallback", "", "The first version to fallback to should there be no tag")
-	dropPrefixFlag := flag.Bool("drop-prefix", false, "Drop prefix from output")
-	prereleaseSuffixFlag := flag.String("prerelease-suffix", "", "Suffix to add to prereleases")
-	formatFlag := flag.String("format", "", "Format of output")
-	flag.Parse()
-
-	dir, err := os.Getwd()
-	if err != nil {
-		log.Fatalf("unable to determine current directory: %v\n", err)
-	}
-	opts := internal.GenerateVersionOptions{
-		FallbackTagName:   *fallbackFlag,
-		DropTagNamePrefix: *dropPrefixFlag,
-		PrereleaseSuffix:  *prereleaseSuffixFlag,
-		Format:            *formatFlag,
-	}
-	result, err := Run(dir, opts)
-	if err != nil {
-		log.Fatalf("unable to generate version: %v\n", err)
+	if err := cmd.Execute(cmd.FullVersion{Version: version, Commit: commit, Date: date, BuiltBy: builtBy}); err != nil {
+		fmt.Printf("%v\n", err)
+		os.Exit(1)
 	}
-	fmt.Println(*result)
 }