chore: Some minor printout fixes (#442)

* chore: Some minor printout fixes

* test fixes

pkg/kn/commands/service/service.go

@@ -46,7 +46,6 @@ func NewServiceCommand(p *commands.KnParams) *cobra.Command {
 }
 
 func waitForService(client serving_kn_v1alpha1.KnServingClient, serviceName string, out io.Writer, timeout int) error {
-	fmt.Println("")
 	err, duration := client.WaitForService(serviceName, time.Duration(timeout)*time.Second, wait.SimpleMessageCallback(out))
 	if err != nil {
 		return err

pkg/kn/commands/service/update.go

@@ -59,7 +59,7 @@ func NewServiceUpdateCommand(p *commands.KnParams) *cobra.Command {
 		Example: update_example,
 		RunE: func(cmd *cobra.Command, args []string) (err error) {
 			if len(args) != 1 {
-				return errors.New("requires the service name.")
+				return errors.New("requires the service name")
 			}
 
 			namespace, err := p.GetNamespace(cmd)
@@ -114,7 +114,7 @@ func NewServiceUpdateCommand(p *commands.KnParams) *cobra.Command {
 
 				out := cmd.OutOrStdout()
 				if !waitFlags.Async {
-					fmt.Fprintf(cmd.OutOrStdout(), "Updating Service '%s' in namespace '%s':\n", args[0], namespace)
+					fmt.Fprintf(out, "Updating Service '%s' in namespace '%s':\n", args[0], namespace)
 					err := waitForService(client, name, out, waitFlags.TimeoutInSeconds)
 					if err != nil {
 						return err
@@ -122,7 +122,6 @@ func NewServiceUpdateCommand(p *commands.KnParams) *cobra.Command {
 					return showUrl(client, name, latestRevisionBeforeUpdate, "updated", out)
 				} else {
 					fmt.Fprintf(out, "Service '%s' updated in namespace '%s'.\n", args[0], namespace)
-
 				}
 
 				return nil

pkg/kn/commands/version.go

@@ -43,17 +43,18 @@ func NewVersionCommand(p *KnParams) *cobra.Command {
 		Use:   "version",
 		Short: "Prints the client version",
 		RunE: func(cmd *cobra.Command, args []string) error {
-			fmt.Printf("Version:      %s\n", Version)
-			fmt.Printf("Build Date:   %s\n", BuildDate)
-			fmt.Printf("Git Revision: %s\n", GitRevision)
-			fmt.Printf("Support:\n")
+			out := cmd.OutOrStdout()
+			fmt.Fprintf(out, "Version:      %s\n", Version)
+			fmt.Fprintf(out, "Build Date:   %s\n", BuildDate)
+			fmt.Fprintf(out, "Git Revision: %s\n", GitRevision)
+			fmt.Fprintf(out, "Support:\n")
 			if m, ok := supportMatrix[ServingVersion]; ok {
-				fmt.Printf("- Serving: %s\n", strings.Join(m.Versions, "  "))
-				fmt.Printf("- API(s):  %s\n", strings.Join(m.APIs, " "))
+				fmt.Fprintf(out, "- Serving: %s\n", strings.Join(m.Versions, "  "))
+				fmt.Fprintf(out, "- API(s):  %s\n", strings.Join(m.APIs, " "))
 			} else {
 				// ensure the go build works when we update,
 				// but version command tests fails to prevent shipping
-				fmt.Printf("- Serving: %s\n", ServingVersion)
+				fmt.Fprintf(out, "- Serving: %s\n", ServingVersion)
 			}
 			return nil
 		},

pkg/kn/commands/version_test.go

@@ -49,6 +49,7 @@ func TestVersion(t *testing.T) {
 		versionCmd            *cobra.Command
 		knParams              *KnParams
 		expectedVersionOutput string
+		output                *bytes.Buffer
 	)
 
 	setup := func() {
@@ -66,12 +67,12 @@ func TestVersion(t *testing.T) {
 
 		knParams = &KnParams{}
 		versionCmd = NewVersionCommand(knParams)
+		output = new(bytes.Buffer)
+		versionCmd.SetOutput(output)
 	}
 
 	t.Run("creates a VersionCommand", func(t *testing.T) {
 		setup()
-		CaptureStdout(t)
-		defer ReleaseStdout(t)
 
 		assert.Equal(t, versionCmd.Use, "version")
 		assert.Equal(t, versionCmd.Short, "Prints the client version")
@@ -80,12 +81,10 @@ func TestVersion(t *testing.T) {
 
 	t.Run("prints version, build date, git revision, supported serving version and APIs", func(t *testing.T) {
 		setup()
-		CaptureStdout(t)
-		defer ReleaseStdout(t)
 
-		err := versionCmd.RunE(nil, []string{})
+		err := versionCmd.RunE(versionCmd, []string{})
 		assert.NilError(t, err)
-		assert.Equal(t, ReadStdout(t), expectedVersionOutput)
+		assert.Equal(t, output.String(), expectedVersionOutput)
 	})
 
 }

pkg/kn/core/root.go

@@ -46,7 +46,7 @@ func NewDefaultKnCommand() *cobra.Command {
 	// and will not be parsed
 	pluginsDir, lookupPluginsInPath, err := extractKnPluginFlags(os.Args)
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "%s\n", err)
+		fmt.Fprintf(os.Stderr, "%v\n", err)
 		os.Exit(1)
 	}
 
@@ -79,8 +79,7 @@ func NewDefaultKnCommandWithArgs(rootCmd *cobra.Command,
 			err := plugin.HandlePluginCommand(pluginHandler, cmdPathPieces)
 			if err != nil {
 				rootCmd.Help()
-				fmt.Println()
-				fmt.Printf("unknown command or plugin \"%s\" for \"kn\"\n", args[1])
+				fmt.Fprintf(rootCmd.OutOrStderr(), "Unknown command or plugin '%s'.\n", args[1])
 				os.Exit(1)
 			}
 		}
@@ -171,8 +170,6 @@ func EmptyAndUnknownSubCommands(cmd *cobra.Command) {
 		if childCmd.HasSubCommands() && childCmd.RunE == nil {
 			childCmd.RunE = func(aCmd *cobra.Command, args []string) error {
 				aCmd.Help()
-				fmt.Println()
-
 				if len(args) == 0 {
 					return fmt.Errorf("please provide a valid sub-command for \"kn %s\"", aCmd.Name())
 				}
@@ -196,7 +193,7 @@ func initConfig() {
 		// Find home directory.
 		home, err := homedir.Dir()
 		if err != nil {
-			fmt.Fprintln(os.Stderr, err)
+			fmt.Fprintf(os.Stderr, "%v\n", err)
 			os.Exit(1)
 		}