code clean

Signed-off-by: Billy Zha <[email protected]>

cmd/oras/internal/option/format.go

@@ -42,8 +42,10 @@ type FormatType struct {
 type Format struct {
 	Type     string
 	Template string
-	Input    string
-	types    []FormatType
+	// FormatFlag can be private once deprecated `--output` is removed from
+	// `oras discover`
+	FormatFlag string
+	types      []FormatType
 }
 
 // ApplyFlag implements FlagProvider.ApplyFlag.
@@ -68,7 +70,7 @@ func (opts *Format) ApplyFlags(fs *pflag.FlagSet) {
 	}
 
 	// apply flags
-	fs.StringVar(&opts.Input, "format", opts.Input, usage)
+	fs.StringVar(&opts.FormatFlag, "format", opts.FormatFlag, usage)
 	fs.StringVar(&opts.Template, "template", "", "Template string used to format output")
 }
 
@@ -98,21 +100,21 @@ func (opts *Format) Parse(_ *cobra.Command) error {
 }
 
 func (opts *Format) parseFlag() error {
-	opts.Type = opts.Input
+	opts.Type = opts.FormatFlag
 	if opts.Template != "" {
 		// template explicitly set
-		opts.Type = opts.Input
+		opts.Type = opts.FormatFlag
 		if opts.Type != FormatTypeGoTemplate {
 			return fmt.Errorf("--template must be used with --format %s", FormatTypeGoTemplate)
 		}
 		return nil
 	}
 
 	goTemplatePrefix := FormatTypeGoTemplate + "="
-	if strings.HasPrefix(opts.Input, goTemplatePrefix) {
+	if strings.HasPrefix(opts.FormatFlag, goTemplatePrefix) {
 		// add parameter to template
 		opts.Type = FormatTypeGoTemplate
-		opts.Template = opts.Input[len(goTemplatePrefix):]
+		opts.Template = opts.FormatFlag[len(goTemplatePrefix):]
 	}
 	return nil
 }
@@ -125,11 +127,16 @@ func (opts *Format) SetTypes(types []FormatType) {
 // SetTypesAndDefault resets the format options and default value.
 // Caller should make sure that this function is used before applying flags.
 func (opts *Format) SetTypesAndDefault(defaultType string, types []FormatType) {
-	opts.Input = defaultType
+	opts.FormatFlag = defaultType
 	opts.types = types
 }
 
-// FormatError generate the error message for an invalid type.
+// FormatError generates the error message for an invalid type.
 func (opts *Format) TypeError() error {
 	return fmt.Errorf("unsupported format type: %s", opts.Type)
 }
+
+// RawFormatFlag returns raw input of --format flag.
+func (opts *Format) RawFormatFlag() string {
+	return opts.FormatFlag
+}

cmd/oras/root/discover.go

@@ -98,7 +98,7 @@ Example - Discover referrers of the manifest tagged 'v1' in an OCI image layout
 	}
 
 	cmd.Flags().StringVarP(&opts.artifactType, "artifact-type", "", "", "artifact type")
-	cmd.Flags().StringVarP(&opts.Format.Input, "output", "o", "tree", "[Deprecated] format in which to display referrers (table, json, or tree). tree format will also show indirect referrers")
+	cmd.Flags().StringVarP(&opts.Format.FormatFlag, "output", "o", "tree", "[Deprecated] format in which to display referrers (table, json, or tree). tree format will also show indirect referrers")
 	opts.SetTypesAndDefault(option.FormatTypeTree, []option.FormatType{
 		{Name: option.FormatTypeTree, Usage: "Get referrers recursively and print in tree format"},
 		{Name: option.FormatTypeTable, Usage: "Get direct referrers and output in table format"},

cmd/oras/root/manifest/fetch.go

@@ -73,7 +73,7 @@ Example - Fetch raw manifest from an OCI layout archive file 'layout.tar':
 		Args: oerrors.CheckArgs(argument.Exactly(1), "the manifest to fetch"),
 		PreRunE: func(cmd *cobra.Command, args []string) error {
 			switch {
-			case opts.outputPath == "-" && opts.Input != "":
+			case opts.outputPath == "-" && opts.RawFormatFlag() != "":
 				return fmt.Errorf("`--output -` cannot be used with `--format %s` at the same time", opts.Template)
 			case opts.outputPath == "-" && opts.OutputDescriptor:
 				return fmt.Errorf("`--descriptor` cannot be used with `--output -` at the same time")