.eleventy.js

const chalk = require("chalk");

module.exports = function(eleventyConfig) {
  let markdownIt = require("markdown-it");
  let markdownItDeflist = require("markdown-it-deflist");
  let markdownItAnchor = require("markdown-it-anchor");
  let { markdownItImageSize } = require("markdown-it-image-size");
  let pluginTOC = require('eleventy-plugin-toc')
  let slugify = function (s) {
    let newStr = String(s).trim().toLowerCase()
      .replace(/\s+/g, '-')
      .replace(/[():.,&'`]/g, '');
    return encodeURIComponent(newStr);
  }
  let markdownItAnchorOpts = {
    slugify,
  };
  let options = {
    html: true,
  };

  eleventyConfig.addShortcode("ref", function(page, title) {
    return `<a href="/${page}/#${slugify(title)}">${title}</a>`;
  });

  eleventyConfig.setLibrary("md", markdownIt(options)
    .use(markdownItAnchor, markdownItAnchorOpts)
    .use(markdownItDeflist)
    .use(markdownItImageSize)
  );

  eleventyConfig.addPassthroughCopy("_assets");

  eleventyConfig.addPlugin(pluginTOC);

  eleventyConfig.addTransform("ellipsis", async function(content, outputPath) {
    return content.replace(/\.\.\./g, "…");
  });

  eleventyConfig.addLinter("naked-url", async function(content, inputPath, outputPath) {
    if (!(inputPath.endsWith(".md"))) {
      return;
    }
    const nakedUrlRegexp = /(?:[^<>";]|^)(https?:(?:[^<\s]+))/g
    const matches = content.matchAll(nakedUrlRegexp);
    const found = [];
    for (const match of matches) {
      found.push(match[1]);
    }
    if (found.length) {
      console.warn(chalk.yellow(`Naked URL Linter (${inputPath}):`));
      console.warn("    " + found.join("\n" + "    "));
    }
  });

  return {
    passthroughFileCopy: true,
    dir: {
      input: "manuscript",
      output: "_site",
      includes: "../_includes"
    }
  };
};