index.js

const fs = require("fs");
const imagemin = require("imagemin");
const loggy = require("loggy");
const plur = require("plur");
const prettyBytes = require("pretty-bytes");

const imageminPattern = /\.(gif|jpg|jpeg|jpe|jif|jfif|jfi|png|svg|svgz)$/;
const imageminPlugins = {
  "imagemin-gifsicle": true,
  "imagemin-jpegtran": true,
  "imagemin-optipng": true,
  "imagemin-svgo": true
};

exports = module.exports = class {
  constructor(config) {
    this.config = config.plugins.imagemin || {};

    if (new Object(this.config.plugins) !== this.config.plugins)
      this.config.plugins = {};

    this.config.plugins = Object.assign(
      {},
      imageminPlugins,
      this.config.plugins
    );
    this.plugins = [];
    let pluginLoads = 0;
    for (let plugin in this.config.plugins) {
      let options = this.config.plugins[plugin];
      if (!options) continue;
      else pluginLoads++;
      try {
        if (new Object(options) === options)
          this.plugins.push(require(plugin)(options));
        else this.plugins.push(require(plugin)());
      } catch (err) {
        loggy.warn(`[imagemin] failed to load ${plugin}:`, err.message);
      }
    }
    if (!this.plugins.length && pluginLoads)
      throw new Error("No imagemin plugins loaded");

    if (!("pattern" in this.config)) this.config.pattern = imageminPattern;
    this.config.pattern = new RegExp(this.config.pattern);
  }

  onCompile(files, assets) {
    let startTime = Date.now();
    let promises = [];
    let oldBytes = 0;
    let newBytes = 0;

    for (let asset of assets) {
      if (!this.config.pattern.test(asset.destinationPath)) continue;

      promises.push(
        new Promise((res, rej) => {
          let data = Buffer.from(asset.compiled);
          oldBytes += data.length;

          imagemin.buffer(data, { plugins: this.plugins }).then(buffer => {
            newBytes += buffer.length;

            fs.writeFile(asset.destinationPath, buffer, err => {
              if (err) rej(err);
              else res();
            });
          });
        })
      );
    }

    Promise.all(promises)
      .then(() => {
        let elapsed = ((Date.now() - startTime) / 1000).toFixed(1);
        let saved = prettyBytes(oldBytes - newBytes);

        loggy.info(
          `[imagemin] minified ${promises.length} ${plur(
            "image",
            promises.length
          )} to save ${saved} in ${elapsed} sec`
        );
      })
      .catch(err => {
        loggy.error("[imagemin] minification failed:", err.message);
      });
  }

  optimize() {}
};

exports.prototype.brunchPlugin = true;