adding on jam summarize for extension

commands/summarize.go

@@ -10,6 +10,7 @@ import (
 
 type summarizeFlags struct {
 	buildpackTarballPath string
+	extensionTarballPath string
 	format               string
 }
 
@@ -19,16 +20,21 @@ func summarize() *cobra.Command {
 		Use:   "summarize",
 		Short: "summarize buildpackage",
 		RunE: func(cmd *cobra.Command, args []string) error {
-			return summarizeRun(*flags)
+			isBuildpack, _ := cmd.Flags().GetString("buildpack")
+			if isBuildpack != "" {
+				return summarizeRun(*flags)
+			} else {
+				return summarizeExtensionRun(*flags)
+			}
 		},
 	}
 	cmd.Flags().StringVar(&flags.buildpackTarballPath, "buildpack", "", "path to a buildpackage tarball (required)")
-	cmd.Flags().StringVar(&flags.format, "format", "markdown", "format of output options are (markdown, json)")
+	cmd.Flags().StringVar(&flags.extensionTarballPath, "extension", "", "path to a buildpackage tarball (required)")
+	cmd.PersistentFlags().StringVar(&flags.format, "format", "markdown", "format of output options are (markdown, json)")
+
+	cmd.MarkFlagsOneRequired("buildpack", "extension")
+	cmd.MarkFlagsMutuallyExclusive("buildpack", "extension")
 
-	err := cmd.MarkFlagRequired("buildpack")
-	if err != nil {
-		fmt.Fprintf(os.Stderr, "Unable to mark buildpack flag as required")
-	}
 	return cmd
 }
 
@@ -55,3 +61,24 @@ func summarizeRun(flags summarizeFlags) error {
 
 	return nil
 }
+
+func summarizeExtensionRun(flags summarizeFlags) error {
+
+	extensionInspector := internal.NewExtensionInspector()
+	formatter := internal.NewExtensionFormatter(os.Stdout)
+	configs, err := extensionInspector.Dependencies(flags.extensionTarballPath)
+	if err != nil {
+		return fmt.Errorf("failed to inspect extension dependencies: %w", err)
+	}
+
+	switch flags.format {
+	case "markdown":
+		formatter.Markdown(configs)
+	case "json":
+		formatter.JSON(configs)
+	default:
+		return fmt.Errorf("unknown format %q, please choose from the following formats: markdown, json)", flags.format)
+	}
+
+	return nil
+}