Sidebar group item cannot contain empty children

[Armaldio]

• I confirm that this is a issue rather than a question.

Bug report

Version

vuepress: ^1.0.0-alpha.37

Steps to reproduce

yarn dev

What is expected?

The project should build and display the page.
Groups with empty childrens should only show the title as of vuepress@0.x

What is actually happening?

The build is successfull but the page is blank it an error is shown in the developer console

Other relevant information

• Your OS: Windows 10
• Node.js version: v10.15.0
• Browser version: Chrome 72
• Is this a global or local install? > Locale
• Which package manager did you use for the install? > yarn

sidebar: [
      {
        title: '1',
        children: [
          ['/intro/', 'Introduction'],
        ],
      },
      {
        title: '2',
        children: [],
      },
    }
}

[ulivz]

Thanks for the report, this is a regression bug of 11ce576

Since a sidebar group item can also have a path item from 1.0-alpha.36, so VuePress will intentionally convert the empty sidebar group item to a page item so that the headers of that page can be shown.