@radicle/gray-matter/lib/engines.js

Parse front-matter from a string or file. Fast, reliable and easy to use. Parses YAML front matter by default, but also has support for YAML, JSON, TOML or Coffee Front-Matter, with options to set custom delimiters. Used by metalsmith, assemble, verb and

'use strict';

const yaml = require('js-yaml');

/**
 * Default engines
 */

const engines = exports = module.exports;

/**
 * YAML
 */

engines.yaml = {
  parse: yaml.load.bind(yaml),
  stringify: yaml.dump.bind(yaml)
};

/**
 * JSON
 */

engines.json = {
  parse: JSON.parse.bind(JSON),
  stringify: function(obj, options) {
    const opts = Object.assign({replacer: null, space: 2}, options);
    return JSON.stringify(obj, opts.replacer, opts.space);
  }
};

/**
 * JavaScript
 */

engines.javascript = {
  parse: function parse(str, options, wrap) {
    /* eslint no-eval: 0 */
    try {
      if (wrap !== false) {
        str = '(function() {\nreturn ' + str.trim() + ';\n}());';
      }
      return eval(str) || {};
    } catch (err) {
      if (wrap !== false && /(unexpected|identifier)/i.test(err.message)) {
        return parse(str, options, false);
      }
      throw new SyntaxError(err);
    }
  },
  stringify: function() {
    throw new Error('stringifying JavaScript is not supported');
  }
};