Run help from default command's parent only if help option is first

Author: aweebit

lib/command.js

@@ -1272,10 +1272,7 @@ Expecting one of '${allowedValues.join("', '")}'`);
     }
     if (this._defaultCommandName) {
       // Run the help for default command from parent rather than passing to default command
-      const helpOptionProvided = this._hasHelpOption && unknown.find(
-        arg => arg === this._helpOption.long || arg === this._helpOption.short
-      );
-      if (helpOptionProvided) {
+      if (this._hasHelpOption && this._helpOption.is(unknown[0])) {
         this.emit('option:' + this._helpOption.name());
       }
       return this._dispatchSubcommand(this._defaultCommandName, operands, unknown);

lib/option.js

@@ -220,13 +220,13 @@ class Option {
   /**
    * Check if `arg` matches the short or long flag.
    *
-   * @param {string} arg
+   * @param {string | undefined} arg
    * @return {boolean}
    * @api private
    */
 
   is(arg) {
-    return this.short === arg || this.long === arg;
+    return arg && (this.short === arg || this.long === arg);
   }
 
   /**