.eleventy.js

const markdownIt = require('markdown-it')({
  html: true,
  breaks: false,
  linkify: true,
  typographer: true
});

const formatDate = (date, format) => {
  const months = [
    'January',
    'February',
    'March',
    'April',
    'May',
    'June',
    'July',
    'August',
    'September',
    'October',
    'November',
    'December',
  ];

  const days = [
    'Sunday',
    'Monday',
    'Tuesday',
    'Wednesday',
    'Thursday',
    'Friday',
    'Saturday',
  ]

  const m0 = date.getMonth();
  const mm = `${m0 + 1}`.padStart(2, '0');
  const MM = months[m0];
  const M = MM.slice(0, 3);
  const d = date.getDate();
  const dd = `${d}`.padStart(2, '0');
  const D = days[date.getDay()];
  const yyyy = date.getFullYear();

  const formats = {
    'day': `${D}`,
    'date': `${d}`,
    'month': `${mm}`,
    'month-name': `${MM}`,
    'year': `${yyyy}`,
    'numeric': `${mm}/${dd}/${yyyy}`,
    'url': `${yyyy}/${mm}/${dd}`,
    'short': `${M} ${d}, ${yyyy}`,
    'long': `${MM} ${d}, ${yyyy}`,
  }

  return formats[format];
}

const getDate = (format = null, date = null) => {
  const now = date ? new Date(date) : new Date();
  return format ? formatDate(now, format) : now;
}

module.exports = (eleventyConfig) => {
  eleventyConfig.addPassthroughCopy('assets');
  eleventyConfig.addPassthroughCopy('CNAME');

  eleventyConfig.addFilter("typeOf", (val) => {
    return typeof val;
  });

  eleventyConfig.addFilter("formatDate", (date, format = 'short') => {
    return formatDate(date, format);
  });

  eleventyConfig.addFilter("getDate", (date = null, format = 'short') => {
    return getDate(format, date);
  });

  eleventyConfig.addFilter("md", (content, inline = false) => {
    return inline
      ? markdownIt.renderInline(content)
      : markdownIt.render(content);
  });

  eleventyConfig.addShortcode("getDate", (format = null) => {
    return getDate(format);
  });

  eleventyConfig.addPairedShortcode("markdown", (content, inline = null) => {
    return inline
      ? markdownIt.renderInline(content)
      : markdownIt.render(content);
  });

  /* Markdown */
  eleventyConfig.setLibrary('md', markdownIt);

  return {
    markdownTemplateEngine: "njk",
    dir: { output: "docs" },
  }
};