empress-blog/lib/automatic-new-tag.js

Fully-functional, SEO friendly static site implementation of a blog system built on Ember.

/* eslint-disable prettier/prettier */
const BroccoliPlugin = require('broccoli-plugin');
const walkSync = require('walk-sync');
const { readFileSync, writeFileSync } = require('fs');
const { join } = require('path');
const yamlFront = require('yaml-front-matter');
const yaml = require('js-yaml');
const _ = require('lodash');

module.exports = class AutomaticNewTag extends BroccoliPlugin {
  constructor(folder, options) {
    super([folder], options);
  }

  build() {
    this.inputPaths.forEach((dir) => {

      const markdownFiles = walkSync(dir)
        .filter(path => path.endsWith('.md'));

      _.chain(markdownFiles)
        .map((file) => {
          const fileContents = readFileSync(join(dir, file));
          return {
            frontMatter: yamlFront.loadFront(fileContents),
            file,
          };
        })
        .sortBy(({frontMatter}) => {
          return new Date(frontMatter.date);
        })
        .reverse()
        .forEach(({file, frontMatter}, index) => {
          if (!frontMatter.tags) {
            frontMatter.tags = [];
          }

          if (frontMatter.tags.includes('new')) {
            // eslint-disable-next-line no-console
            console.warn(`The tag "new" is deprecated, "new" is automatically added as a tag to the 4 most recent posts now. File: ${file}`);
            delete frontMatter.new;
          }

          if (index < 4) {
            frontMatter.tags.push('new');
          }

          const content = frontMatter.__content;
          delete frontMatter.__content;

          const fileContent = `---
${yaml.safeDump(frontMatter)}---${content}`;

          writeFileSync(join(this.outputPath,file), fileContent);
        })
        .value();
    });
  }
}