Refactor version command to cobra lib

Signed-off-by: Marco Franssen <marco.franssen@philips.com>

cmd/slsa-provenance/cli/version.go

@@ -1,18 +1,43 @@
 package cli
 
 import (
-	"context"
 	"encoding/json"
-	"flag"
 	"fmt"
-	"io"
 	"runtime"
 	"strings"
 	"text/tabwriter"
 
-	"github.com/peterbourgon/ff/v3/ffcli"
+	"github.com/spf13/cobra"
 )
 
+// Version creates an instance of *cobra.Command to print version info
+func Version() *cobra.Command {
+	var outputJSON bool
+
+	cmd := &cobra.Command{
+		Use:   "version",
+		Short: fmt.Sprintf("Prints the %s version", CLIName),
+		Long:  fmt.Sprintf("Prints the %s version", CLIName),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			v := VersionInfo()
+			res := v.String()
+			if outputJSON {
+				j, err := v.JSONString()
+				if err != nil {
+					return fmt.Errorf("unable to generate JSON from version info: %w", err)
+				}
+				res = j
+			}
+			fmt.Fprintln(cmd.OutOrStdout(), res)
+			return nil
+		},
+	}
+
+	cmd.Flags().BoolVar(&outputJSON, "json", false, "print version information as JSON")
+
+	return cmd
+}
+
 // Base version information.
 //
 // This is the fallback data used when version information from git is not
@@ -29,37 +54,6 @@ var (
 	buildDate = "unknown"
 )
 
-// Version creates an instance of *ffcli.Command to print version info
-func Version(w io.Writer) *ffcli.Command {
-	var (
-		flagset = flag.NewFlagSet("slsa-provenance version", flag.ExitOnError)
-		outJSON = flagset.Bool("json", false, "print JSON instead of text")
-	)
-
-	flagset.SetOutput(w)
-
-	return &ffcli.Command{
-		Name:       "version",
-		ShortUsage: "slsa-provenance version",
-		ShortHelp:  "Prints the slsa-provenance version",
-		FlagSet:    flagset,
-		Exec: func(ctx context.Context, args []string) error {
-			v := VersionInfo()
-			res := v.String()
-			if *outJSON {
-				j, err := v.JSONString()
-				if err != nil {
-					return fmt.Errorf("unable to generate JSON from version info: %w", err)
-				}
-				res = j
-			}
-
-			fmt.Fprintln(w, res)
-			return nil
-		},
-	}
-}
-
 // Info holds the version information of the binary
 type Info struct {
 	GitVersion   string `json:"git_version,omitempty"`

cmd/slsa-provenance/cli/version_test.go

@@ -1,10 +1,8 @@
 package cli_test
 
 import (
-	"context"
 	"fmt"
 	"runtime"
-	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -15,9 +13,6 @@ import (
 func TestVersionCliText(t *testing.T) {
 	assert := assert.New(t)
 
-	sb := strings.Builder{}
-	cli := cli.Version(&sb)
-
 	expected := fmt.Sprintf(`GitVersion:    devel
 GitCommit:     unknown
 GitTreeState:  unknown
@@ -28,17 +23,14 @@ Platform:      %s/%s
 
 `, runtime.Version(), runtime.Compiler, runtime.GOOS, runtime.GOARCH)
 
-	err := cli.ParseAndRun(context.Background(), nil)
+	output, err := executeCommand(cli.Version())
 	assert.NoError(err)
-	assert.Equal(expected, sb.String())
+	assert.Equal(expected, output)
 }
 
 func TestVersionCliJSON(t *testing.T) {
 	assert := assert.New(t)
 
-	sb := strings.Builder{}
-	cli := cli.Version(&sb)
-
 	expected := fmt.Sprintf(`{
   "git_version": "devel",
   "git_commit": "unknown",
@@ -50,7 +42,7 @@ func TestVersionCliJSON(t *testing.T) {
 }
 `, runtime.Version(), runtime.Compiler, runtime.GOOS, runtime.GOARCH)
 
-	err := cli.ParseAndRun(context.Background(), []string{"-json"})
+	output, err := executeCommand(cli.Version(), "--json")
 	assert.NoError(err)
-	assert.Equal(expected, sb.String())
+	assert.Equal(expected, output)
 }

go.mod

@@ -13,8 +13,11 @@ require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/google/go-querystring v1.1.0 // indirect
+	github.com/inconshreveable/mousetrap v1.0.0 // indirect
 	github.com/kr/pretty v0.3.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/spf13/cobra v1.2.1 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
 	golang.org/x/crypto v0.0.0-20211108221036-ceb1ce70b4fa // indirect
 	golang.org/x/net v0.0.0-20211108170745-6635138e15ea // indirect
 	google.golang.org/appengine v1.6.7 // indirect