eleventy.config.cjs

const { DateTime } = require("luxon");
const markdownItAnchor = require("markdown-it-anchor");

const pluginRss = require("@11ty/eleventy-plugin-rss");
const pluginSyntaxHighlight = require("@11ty/eleventy-plugin-syntaxhighlight");
const pluginBundle = require("@11ty/eleventy-plugin-bundle");
const pluginNavigation = require("@11ty/eleventy-navigation");
const pluginTimeToRead = require("eleventy-plugin-time-to-read");

const pluginDrafts = require("./eleventy.config.drafts.cjs");
const pluginImages = require("./eleventy.config.images.cjs");

module.exports = async function (eleventyConfig) {
  const { EleventyHtmlBasePlugin } = await import("@11ty/eleventy");

  // Copy the contents of the `public` folder to the output folder
  // For example, `./public/css/` ends up in `_site/css/`
  eleventyConfig.addPassthroughCopy({
    "./public/": "/",
    "./node_modules/prismjs/themes/prism-okaidia.css": "/css/prism-okaidia.css",
  });
  eleventyConfig.addPassthroughCopy("CNAME");

  // Run Eleventy when these files change:
  // https://www.11ty.dev/docs/watch-serve/#add-your-own-watch-targets

  // Watch content images for the image pipeline.
  eleventyConfig.addWatchTarget("content/**/*.{svg,webp,png,jpeg}");

  // App plugins
  eleventyConfig.addPlugin(pluginDrafts);
  eleventyConfig.addPlugin(pluginImages);

  // Official plugins
  eleventyConfig.addPlugin(pluginRss);
  eleventyConfig.addPlugin(pluginSyntaxHighlight, {
    preAttributes: { tabindex: 0 },
  });
  eleventyConfig.addPlugin(pluginNavigation);
  eleventyConfig.addPlugin(EleventyHtmlBasePlugin);
  eleventyConfig.addPlugin(pluginBundle);

  eleventyConfig.addPlugin(pluginTimeToRead, {
    style: "short",
  });

  // Filters
  eleventyConfig.addFilter("readableDate", (date, format, zone) => {
    // Formatting tokens for Luxon: https://moment.github.io/luxon/#/formatting?id=table-of-tokens
    const obj = typeof date === "string"
      ? DateTime.fromFormat(date, "yyyy-mm-dd", { zone: zone || "utc" })
      : DateTime.fromJSDate(date, { zone: zone || "utc" });
    return obj.toFormat(format || "dd LLLL yyyy");
  });

  eleventyConfig.addFilter("htmlDateString", (date) => {
    // dateObj input: https://html.spec.whatwg.org/multipage/common-microsyntaxes.html#valid-date-string
    const obj = typeof date === "string"
      ? DateTime.fromFormat(date, "yyyy-mm-dd", { zone: "utc" })
      : DateTime.fromJSDate(date, { zone: "utc" });
    return obj.toFormat("yyyy-LL-dd");
  });

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

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

  // Return the smallest number argument
  eleventyConfig.addFilter("min", (...numbers) => {
    return Math.min.apply(null, numbers);
  });

  // Return all the tags used in a collection
  eleventyConfig.addFilter("getAllTags", collection => {
    let tagSet = new Set();
    for (let item of collection) {
      (item.data.tags || []).forEach(tag => tagSet.add(tag));
    }
    return Array.from(tagSet);
  });

  eleventyConfig.addFilter("getNextJournalEntry", function (collection) {
    const currIndex = collection.findIndex(item =>
      item.inputPath === this.page.inputPath
      && (item.outputPath === this.page.outputPath || item.url === this.page.url)
    );
    for (let i = currIndex; i < collection.length; i++) {
      if (item.data.campaign === this.page.data.campaign) {
        return item;
      }
    }
  });

  eleventyConfig.addFilter("getPrevJournalEntry", function (collection) {
    const currIndex = collection.findIndex(item =>
      item.inputPath === this.page.inputPath
      && (item.outputPath === this.page.outputPath || item.url === this.page.url)
    );
    for (let i = currIndex - 1; i <= 0; i--) {
      if (item.data.campaign === this.page.data.campaign) {
        return item;
      }
    }
  });

  eleventyConfig.addFilter("filterTagList", function filterTagList(tags) {
    return (tags || []).filter(tag => ["all", "nav", "post", "posts"].indexOf(tag) === -1);
  });

  // Customize Markdown library settings:
  eleventyConfig.amendLibrary("md", mdLib => {
    mdLib.use(markdownItAnchor, {
      permalink: markdownItAnchor.permalink.ariaHidden({
        placement: "after",
        class: "header-anchor",
        symbol: "#",
        ariaHidden: false,
      }),
      level: [1, 2, 3, 4],
      slugify: eleventyConfig.getFilter("slugify"),
    });
  });

  eleventyConfig.addShortcode("currentBuildDate", () => {
    return (new Date()).toISOString();
  });

  // Features to make your build faster (when you need them)

  // If your passthrough copy gets heavy and cumbersome, add this line
  // to emulate the file copy on the dev server. Learn more:
  // https://www.11ty.dev/docs/copy/#emulate-passthrough-copy-during-serve

  // eleventyConfig.setServerPassthroughCopyBehavior("passthrough");

  return {
    // Control which files Eleventy will process
    // e.g.: *.md, *.njk, *.html, *.liquid
    templateFormats: [
      "md",
      "njk",
      "html",
      "liquid",
    ],

    // Pre-process *.md files with: (default: `liquid`)
    markdownTemplateEngine: "njk",

    // Pre-process *.html files with: (default: `liquid`)
    htmlTemplateEngine: "njk",

    // These are all optional:
    dir: {
      input: "content", // default: "."
      includes: "../_includes", // default: "_includes"
      data: "../_data", // default: "_data"
      output: "_site",
    },

    // -----------------------------------------------------------------
    // Optional items:
    // -----------------------------------------------------------------

    // If your site deploys to a subdirectory, change `pathPrefix`.
    // Read more: https://www.11ty.dev/docs/config/#deploy-to-a-subdirectory-with-a-path-prefix

    // When paired with the HTML <base> plugin https://www.11ty.dev/docs/plugins/html-base/
    // it will transform any absolute URLs in your HTML to include this
    // folder name and does **not** affect where things go in the output folder.
    pathPrefix: "/",
  };
};