Add missing check for broken passThrough

lib/command.js

@@ -272,6 +272,8 @@ class Command extends EventEmitter {
 
     this.commands.push(cmd);
     cmd.parent = this;
+    cmd._checkForBrokenPassThrough();
+
     return this;
   }
 
@@ -735,12 +737,20 @@ Expecting one of '${allowedValues.join("', '")}'`);
    */
   passThroughOptions(passThrough = true) {
     this._passThroughOptions = !!passThrough;
-    if (!!this.parent && passThrough && !this.parent._enablePositionalOptions) {
-      throw new Error('passThroughOptions can not be used without turning on enablePositionalOptions for parent command(s)');
-    }
+    this._checkForBrokenPassThrough();
     return this;
   }
 
+  /**
+   * @api private
+   */
+
+  _checkForBrokenPassThrough() {
+    if (this.parent && this._passThroughOptions && !this.parent._enablePositionalOptions) {
+      throw new Error(`passThroughOptions cannot be used for '${this._name}' without turning on enablePositionalOptions for parent command(s)`);
+    }
+  }
+
   /**
     * Whether to store option values as properties on command object,
     * or store separately (specify false). In both cases the option values can be accessed using .opts().

tests/command.positionalOptions.test.js

@@ -362,13 +362,25 @@ describe('program with action handler and positionalOptions and subcommand', ()
 
 // ------------------------------------------------------------------------------
 
-test('when program not positional and turn on passthrough in subcommand then error', () => {
-  const program = new commander.Command();
-  const sub = program.command('sub');
+describe('broken passThrough', () => {
+  test('when program not positional and turn on passThroughOptions in subcommand then error', () => {
+    const program = new commander.Command();
+    const sub = program.command('sub');
+
+    expect(() => {
+      sub.passThroughOptions();
+    }).toThrow();
+  });
 
-  expect(() => {
-    sub.passThroughOptions();
-  }).toThrow();
+  test('when program not positional and add subcommand with passThroughOptions then error', () => {
+    const program = new commander.Command();
+    const sub = new commander.Command('sub')
+      .passThroughOptions();
+
+    expect(() => {
+      program.addCommand(sub);
+    }).toThrow();
+  });
 });
 
 // ------------------------------------------------------------------------------