Cache not properly invalidated when markdown.extendMarkdown changes

[SunriseFox]

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

Bug report

Version

^1.0.0-alpha.20

Steps to reproduce

• create a md file
• compile and run
• edit markdown.extendMarkdown in config.js, don't touch the md
• compile and run
• the new markdown.extendMarkdown won't get called at all, or won't properly reflect changes.

delete node_modules\@vuepress\core\node_modules\.cache then it works

What is expected?

• all md files are properly recompiled.

What is actually happening?

• the new markdown.extendMarkdown won't get called at all.
• no md file is recompiled.

Other relevant information

• Your OS: Ubuntu 18.04 WSL
• Node.js version: 11.1.0
• Browser version: N/A
• Is this a global or local install? local
• Which package manager did you use for the install? npm

[ulivz]

Fixed and published at 1.0.0-alpha.21.

[Mrminfive]

The changes did not take into account the setting of the plugin.