.eleventy.js

const { DateTime } = require("luxon");
const pluginRss = require("@11ty/eleventy-plugin-rss");
const pluginSyntaxHighlight = require("@11ty/eleventy-plugin-syntaxhighlight");

module.exports = function (eleventyConfig) {
  eleventyConfig.addPlugin(pluginRss);
  eleventyConfig.addPlugin(pluginSyntaxHighlight);
  eleventyConfig.setDataDeepMerge(true);

  eleventyConfig.addLayoutAlias("post", "layouts/post.njk");

  eleventyConfig.addFilter("readableDate", dateObj => {
    return DateTime.fromJSDate(dateObj, { zone: 'utc' }).toFormat("dd LLL yyyy");
  });

  // https://html.spec.whatwg.org/multipage/common-microsyntaxes.html#valid-date-string
  eleventyConfig.addFilter('htmlDateString', (dateObj) => {
    return DateTime.fromJSDate(dateObj).toFormat('yyyy-LL-dd');
  });

  // Get the first `n` elements of a collection.
  eleventyConfig.addFilter("head", (array, n) => {
    if (n < 0) {
      return array.slice(n);
    }

    return array.slice(0, n);
  });

  // https://html.spec.whatwg.org/multipage/common-microsyntaxes.html#valid-date-string
  eleventyConfig.addFilter('htmlDateString', (dateObj) => {
    return DateTime.fromJSDate(dateObj).toFormat('yyyy-LL-dd');
  });

  // only content in the `posts/` directory
  eleventyConfig.addCollection("posts", function (collection) {
    return collection.getFilteredByGlob("./src/posts/*").sort(function (a, b) {
      return a.date - b.date;
    });
  });

  // Universal slug filter strips unsafe chars from URLs
  eleventyConfig.addFilter("slugify", function (str) {
    return slugify(str, {
      lower: true,
      replacement: "-",
      remove: /[*+~.·,()'"`´%!?¿:@]/g
    });
  });

  eleventyConfig.addCollection("tagList", require("./src/_11ty/getTagList"));

  /* Markdown Plugins */
  let markdownIt = require("markdown-it");
  let markdownItAnchor = require("markdown-it-anchor");
  let options = {
    html: true,
    breaks: true,
    linkify: true
  };
  let opts = {
    permalink: true,
    permalinkClass: "direct-link",
    permalinkSymbol: "#"
  };

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

  return {
    templateFormats: [
      "md",
      "njk",
      "html",
      "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",
    passthroughFileCopy: true,
    dir: {
      input: "./src",
      includes: "_includes",
      data: "_data",
      output: "dist"
    }
  };
};