lib: emit localstorage-file warning only once

Author: danielmbrasil

lib/internal/webstorage.js

@@ -24,14 +24,23 @@ ObjectDefineProperties(module.exports, {
         const location = getOptionValue('--localstorage-file');
 
         if (location === '') {
+          let warningEmitted = false;
           const handler = {
             __proto__: null,
             get(target, prop) {
-              process.emitWarning('`--localstorage-file` was provided without a valid path');
+              if (!warningEmitted) {
+                process.emitWarning('`--localstorage-file` was provided without a valid path');
+                warningEmitted = true;
+              }
+
               return undefined;
             },
             set(target, prop, value) {
-              process.emitWarning('`--localstorage-file` was provided without a valid path');
+              if (!warningEmitted) {
+                process.emitWarning('`--localstorage-file` was provided without a valid path');
+                warningEmitted = true;
+              }
+
               return false;
             },
           };