.eleventy.js

const { DateTime } = require('luxon')
const CleanCSS = require('clean-css')
const UglifyJS = require('uglify-js')
const htmlmin = require('html-minifier')
const eleventyNavigationPlugin = require('@11ty/eleventy-navigation')

module.exports = function (eleventyConfig) {
  // Eleventy Navigation https://www.11ty.dev/docs/plugins/navigation/
  eleventyConfig.addPlugin(eleventyNavigationPlugin)

  // Configuration API: use eleventyConfig.addLayoutAlias(from, to) to add
  // layout aliases! Say you have a bunch of existing content using
  // layout: post. If you don’t want to rewrite all of those values, just map
  // post to a new file like this:
  // eleventyConfig.addLayoutAlias("post", "layouts/my_new_post_layout.njk");

  // Merge data instead of overriding
  // https://www.11ty.dev/docs/data-deep-merge/
  eleventyConfig.setDataDeepMerge(true)

  // Add support for maintenance-free post authors
  // Adds an authors collection using the author key in our post frontmatter
  // Thanks to @pdehaan: https://github.com/pdehaan
  eleventyConfig.addCollection('authors', (collection) => {
    const blogs = collection.getFilteredByGlob('posts/*.md')
    return blogs.reduce((coll, post) => {
      const author = post.data.author
      if (!author) {
        return coll
      }
      if (!coll.hasOwnProperty(author)) {
        coll[author] = []
      }
      coll[author].push(post.data)
      return coll
    }, {})
  })

  // Date formatting (human readable)
  eleventyConfig.addFilter('readableDate', (dateObj) => {
    return DateTime.fromJSDate(dateObj).toFormat('dd LLL yyyy')
  })

  // Date formatting (machine readable)
  eleventyConfig.addFilter('machineDate', (dateObj) => {
    return DateTime.fromJSDate(dateObj).toFormat('yyyy-MM-dd')
  })

  // Minify CSS
  eleventyConfig.addFilter('cssmin', function (code) {
    return new CleanCSS({}).minify(code).styles
  })

  // Minify JS
  eleventyConfig.addFilter('jsmin', function (code) {
    let minified = UglifyJS.minify(code)
    if (minified.error) {
      console.log('UglifyJS error: ', minified.error)
      return code
    }
    return minified.code
  })

  // Minify HTML output
  eleventyConfig.addTransform('htmlmin', function (content, outputPath) {
    if (outputPath.indexOf('.html') > -1) {
      let minified = htmlmin.minify(content, {
        useShortDoctype: true,
        removeComments: true,
        collapseWhitespace: true
      })
      return minified
    }
    return content
  })

  // Don't process folders with static assets e.g. images
  eleventyConfig.addPassthroughCopy('favicon.ico')
  eleventyConfig.addPassthroughCopy('static/img')
  eleventyConfig.addPassthroughCopy('docs')
  eleventyConfig.addPassthroughCopy('demo')
  eleventyConfig.addPassthroughCopy('admin/')

  eleventyConfig.addPassthroughCopy({ tlas: '/' })

  // We additionally output a copy of our CSS for use in Netlify CMS previews
  eleventyConfig.addPassthroughCopy('_includes/assets/css/inline.css')

  /* Markdown Plugins */
  let markdownIt = require('markdown-it')
  let markdownItAnchor = require('markdown-it-anchor')
  let options = {
    breaks: true,
    linkify: true
  }
  let opts = {
    permalink: false
  }

  eleventyConfig.setLibrary('md', markdownIt(options).use(markdownItAnchor, opts))

  return {
    templateFormats: ['md', 'njk', 'liquid'],

    // If your site lives in a different subdirectory, change this.
    // Leading or trailing slashes are all normalized away, so don’t worry about it.
    // If you don’t have a subdirectory, use "" or "/" (they do the same thing)
    // This is only used for URLs (it does not affect your file structure)
    pathPrefix: '/',

    markdownTemplateEngine: 'liquid',
    htmlTemplateEngine: 'njk',
    dataTemplateEngine: 'njk',
    dir: {
      input: '.',
      includes: '_includes',
      data: '_data',
      output: '_site'
    }
  }
}