[Bug] onEnterRules fails with 'Javascript'

Reproducible in vscode.dev or in VS Code Desktop?

• Not reproducible in vscode.dev or VS Code Desktop

Reproducible in the monaco editor playground?

• Not reproducible in the monaco editor playground

Monaco Editor Playground Link

The snippet posted in https://github.com/microsoft/monaco-editor/issues/159#issuecomment-248728427 works fine as it is. However, it no longer works if the language is changed to 'javascript'.

Playground

Monaco Editor Playground Code

const value = `function hello() {
	alert('Hello world!');
}

// comment line 1
// comment line 2`;


monaco.languages.register({ id: 'mySpecialLanguage' });

monaco.editor.create(document.getElementById("container"), {
  value,
  language: 'mySpecialLanguage',
});

monaco.languages.setLanguageConfiguration('mySpecialLanguage', {
  onEnterRules: [
    {
      beforeText: /[0-9]$/,
      action: {
        indentAction: monaco.languages.IndentAction.None,
        appendText: 'hello world!'
      }
    }
  ]
});

Reproduction Steps

Change 'mySpecialLanguage' to 'javascript'

Actual (Problematic) Behavior

onEnterRules does not function with 'javascript'

Expected Behavior

onEnterRules to function with 'javascript'

Additional Context

No response

Start with the linked Monaco Editor Playground and reproduce the difference between the custom language and JavaScript using the provided onEnterRules snippet. Trace the language-configuration entry point for JavaScript and verify that onEnterRules executes there without changing the expected custom-language behavior.