feat: improve error handling

cmd/add.go

@@ -21,7 +21,7 @@ func init() {
 }
 
 var addCmd = &cobra.Command{
-	Use:   "add [license]",
+	Use:   "add [license id]",
 	Short: "Add LICENSE based on SPDX ID",
 	Args:  cobra.ExactArgs(1),
 	Run: func(cmd *cobra.Command, args []string) {
@@ -39,13 +39,18 @@ var addCmd = &cobra.Command{
 		}
 
 		err = license.Gen()
-		if err != nil && err.Error() == "usupported license" {
+		if err != nil {
+			if err.Error() == "usupported license" {
 				fmt.Printf("Error: There is no '%s' license\n", licenseID)
 				os.Exit(2)
+			} else {
+        fmt.Println("Internal Error:", err)
+        os.Exit(127)
+      }
 		}
 
 		if err = license.Write(OutputFile); err != nil {
-			panic(err)
+      fmt.Println("Error: Can't write file:", err)
 		}
 	},
 }

cmd/list.go

@@ -2,6 +2,7 @@ package cmd
 
 import (
 	"fmt"
+	"os"
 	"strings"
 
 	t "go.wzykubek.xyz/licensmith/internal/template"
@@ -17,7 +18,12 @@ var listCmd = &cobra.Command{
 	Use:   "list",
 	Short: "List available licenses",
 	Run: func(cmd *cobra.Command, args []string) {
-		templates := t.List()
+		templates, err := t.List()
+    if err != nil {
+      fmt.Println("Internal Error:", err)
+      os.Exit(127)
+    }
+
 		fmt.Println(strings.Join(templates, ", "))
 	},
 }

internal/license/license.go

@@ -22,7 +22,10 @@ func (l *License) Gen() error {
 		return errors.New("usupported license")
 	}
 
-	body, _ := template.New(l.ID).Parse(tmpl.Body)
+	body, err := template.New(l.ID).Parse(tmpl.Body)
+  if err != nil {
+    return err
+  }
 
 	var output bytes.Buffer
 	body.Execute(&output, l.Context)

internal/template/template.go

@@ -36,10 +36,10 @@ func Parse(path string) (Template, error) {
 	return tmpl, nil
 }
 
-func List() []string {
+func List() ([]string, error) {
 	files, err := fs.ReadDir(FS, ".")
 	if err != nil {
-		panic(err)
+		return []string{}, err
 	}
 
 	var templates []string
@@ -47,5 +47,5 @@ func List() []string {
 		templates = append(templates, strings.Replace(v.Name(), ".tmpl", "", 1))
 	}
 
-	return templates
+	return templates, nil
 }