Check if configuration file exists and is not a directory

internal/root/root.go

@@ -2,6 +2,7 @@ package root
 
 import (
 	"fmt"
+	"os"
 
 	"github.com/BurntSushi/toml"
 	"github.com/bensallen/hkmgr/internal/config"
@@ -76,6 +77,15 @@ func Run() error {
 		debug = true
 	}
 
+	cfgStat, err := os.Stat(configPath)
+
+	if os.IsNotExist(err) {
+		return fmt.Errorf("configuration file %s not found", configPath)
+	}
+	if cfgStat.IsDir() {
+		return fmt.Errorf("configuration file %s is a directory", configPath)
+	}
+
 	var config config.Config
 	if _, err := toml.DecodeFile(configPath, &config); err != nil {
 		return err