eleventy.config.js

import { DateTime } from 'luxon';
import {feedPlugin} from '@11ty/eleventy-plugin-rss';
import pluginSyntaxHighlight from '@11ty/eleventy-plugin-syntaxhighlight';
import markdownIt from 'markdown-it';
import markdownItAnchor from 'markdown-it-anchor';

export default async function(eleventyConfig) {
  eleventyConfig.addPlugin(feedPlugin, {
    type: "atom",
    outputPath: "/feed.xml",
    collection: {
      name: "posts", // iterate over `collections.posts`
      limit: 0,
    },
    metadata: {
      language: "en",
      title: "Niels Krijger",
      subtitle: "Software stuff.",
      base: "https://nielskrijger.com",
      author: {
        name: "Niels Krijger"
      }
    }
  });
  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);
  });

  eleventyConfig.addCollection('tagList', function (collectionsApi) {
    const tagSet = new Set();
    collectionsApi.getAll().forEach(item => {
      if ('tags' in item.data) {
        const tags = item.data.tags.filter(item => {
          switch (item) {
              // this list should match the `filter` list in tags.njk
            case 'all':
            case 'nav':
            case 'post':
            case 'posts':
              return false;
          }

          return true;
        });

        for (const tag of tags) {
          tagSet.add(tag);
        }
      }
    });

    const result = Array.from(tagSet);
    result.sort(); // Sort alphabetically
    return result;
  });

  eleventyConfig.addPassthroughCopy('img');
  eleventyConfig.addPassthroughCopy('css');

  /* Markdown Plugins */
  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'],
    pathPrefix: '/',
    markdownTemplateEngine: 'liquid',
    htmlTemplateEngine: 'njk',
    dataTemplateEngine: 'njk',
    passthroughFileCopy: true,
  };
};