gulp-mjml/src/index.js

Add Gulp to your MJML workflow

const through = require("through2");
const mjmlDefaultEngine = require("mjml");
const replaceExt = require("replace-ext");
const PluginError = require("plugin-error");

const NAME = "MJML";

function error(file) {
  return function(message) {
    return new PluginError(NAME, "Error in file " + file + ": " + message);
  };
}

module.exports = function mjml(mjmlEngine, options) {
  if (!mjmlEngine) {
    mjmlEngine = mjmlDefaultEngine;
  }
  if (options === undefined) {
    options = {};
  }

  return through.obj(function(file, enc, callback) {
    // Not a big fan of this deep copy methods
    // But it will work regardless of Node version
    const localOptions = JSON.parse(JSON.stringify(options));
    if (localOptions.filePath === undefined) {
      localOptions.filePath = file.path.toString();
    }

    const raise = error(localOptions.filePath);

    if (file.isStream()) {
      this.emit("error", raise("Streams are not supported!"));
      return callback();
    }

    if (file.isBuffer()) {
      const output = file.clone();
      let render;

      try {
        render = mjmlEngine(file.contents.toString(), localOptions);
      } catch (e) {
        this.emit("error", raise(e.message));
        return callback();
      }

      // [DEP0005] DeprecationWarning: Buffer() is deprecated due to security and usability issues
      output.contents = Buffer.from(render.html);
      output.path = replaceExt(file.path.toString(), ".html");
      this.push(output);
    }
    return callback();
  });
};