During the development of the current iteration of my website core, I have encountered with the problem of debugging Metalsmith with its plugin system.

Metalsmith is a lightweight static site generator that has a very flexible plugin system. You can chain together the plugins you like, and Metalsmith will call them one by one passing the current data structure to them. This functional approach makes it hard to understand at first, since there are no visible variables you can look at during execution.

Debug plugin ¶

In order to peek into the data structure, you need to write a small plugin with the required metalsmith plugin interface like so:

let monitor = () => {
  return (files, metalsmith, done) => {
    // console.log(metalsmith._metadata.enhancedTags)
    done()
  }
}

...

metalsmith(__dirname)
  .source('contents')
  .use(monitor())
  .destination('publish')
  .build(function (err) {
    if (err) {
      throw err;
    }
  })

With this small plugin, you are be able to log out any data structure you want by inserting it to the plugin chain.