Simple Javascript SSG

build-site.js

#!/usr/bin/env node

const fs = require('fs');
const path = require('path');

const compile = require('./compiler');

const inputDir = 'content';
const outputDir = 'stage';

let overrides = {};

if (process.argv[2] === 'dev') {
  overrides.baseurl = path.join(__dirname, outputDir) + '/';
}

function processFile(file) {
  console.log('Processing:', file);
  let extension = file.substring(file.lastIndexOf('.') + 1);
  switch (extension) {
    case 'md':
      return {
        path: file.replace(inputDir, outputDir).replace(/md$/, 'html'),
        content: compile(file, overrides)
      };
    case'html':
      return {
        path: file.replace(inputDir, outputDir),
        content: compile(file, overrides)
      };
    case 'css':
      return {
        path: file.replace(inputDir, outputDir),
        content: fs.readFileSync(file, { encoding: 'utf-8' })
      };
    case 'jpg':
    case 'png':
    case 'pdf':
      return {
        path: file.replace(inputDir, outputDir),
        content: fs.readFileSync(file)
      }
    default:
      return undefined;
  }
}

function processDir(dir) {
  let contents = fs.readdirSync(dir);
  let files = contents
    .filter((name) => !fs.lstatSync(path.join(dir, name)).isDirectory());
  let folders = contents
    .filter((name) => fs.lstatSync(path.join(dir, name)).isDirectory());

  files.forEach((file) => {
    let output = processFile(path.join(dir, file));
    if (output) {
      console.log('Writing:', output.path);
      fs.writeFileSync(output.path, output.content);
    } else {
      console.log('Unhandled file:', path.join(dir, file));
    }
  });

  folders.forEach((folder) => {
    let loc = path.join(dir, folder);
    console.log('Making directory:', loc.replace(inputDir, outputDir));
    fs.mkdirSync(loc.replace(inputDir, outputDir));
    processDir(loc);
  })
}

processDir('./content');

compiler.js

const path = require('path');
const hljs = require('highlight.js');
const yaml = require('js-yaml');
const mustache = require('mustache');
const fs = require('fs');
const md = require('markdown-it')({
  html: true,
  xhtmlOut: true,
  breaks: false,
  langPrefix: '',
  linkify: true,
  typographer: true,
  quotes: '“”‘’',
  highlight: function (str, lang) {
    if (lang && hljs.getLanguage(lang)) {
      try {
        return hljs.highlight(lang, str).value;
      } catch (e) {
        console.err(e);
        return '';
      }
    }
  }
}).use(require('markdown-it-sub'))
  .use(require('markdown-it-sup'))
  .use(require('markdown-it-abbr'))
  .use(require('markdown-it-footnote'))
  .use(require('markdown-it-container'), 'warning');
  // Consider: markdown-it-texmath

hljs.configure({
  tabReplace: '    ',
  //useBR: true;
  classPrefix: ''
});

// Loads the files in the given directory into an object with this structure
// { file: 'file content' }
// where file is the filename without its extension
function loadDir(dir) {
  return files = fs.readdirSync(dir)
    .filter((filename) => !fs.lstatSync(path.join(dir, filename)).isDirectory())
    .map((filename) => {
      let name = filename.substring(0, filename.indexOf('.'));
      let content = fs.readFileSync(path.join(dir, filename), { encoding: 'utf-8' });

      let obj = {};
      obj[name] = content;
      return obj;
    })
    .reduce((name, partial) => Object.assign(name, partial), {});
}

// Load sitewide variables
const site = require('./site.json');
let templates = loadDir(site.templatesDir);
let partials = loadDir(site.partialsDir);

function compileMarkdown(filePath, siteOverrides) {
  if (!fs.existsSync(filePath)) {
    throw new Error("File not found: " + filePath);
  }

  const fileText = fs.readFileSync(filePath, { encoding: 'utf-8' });

  let yamlEnd = fileText.indexOf('---', 4);
  let fileYaml = yaml.load(fileText.substring(0, yamlEnd));
  let fileMarkdown = fileText.substring(yamlEnd + 4);

  let config = fileYaml;
  config.site = site;

  if (siteOverrides) {
    Object.assign(config.site, siteOverrides);
  }

  let content = md.render(fileMarkdown);

  let template = templates[config.template.toLowerCase()];

  let vars = config;
  vars.content = content;

  return mustache.render(template, vars, partials);
}

function compileHtml(filePath, siteOverrides) {
  if (!fs.existsSync(filePath)) {
    throw new Error("File not found: " + filePath);
  }

  const fileText = fs.readFileSync(filePath, { encoding: 'utf-8' });

  let config = { site: site };

  if (siteOverrides) {
    Object.assign(config.site, siteOverrides);
  }

  return mustache.render(fileText, config, partials);
}

module.exports = function compile(filePath, siteOverrides) {
  switch (filePath.substring(filePath.lastIndexOf('.'))) {
    case '.md':
      return compileMarkdown(filePath, siteOverrides);
    case '.html':
      return compileHtml(filePath, siteOverrides);
    default:
      console.log("Don't know how to compile file:", filePath);
      return '';
  }
}