Function fetch

src/index.js:84–121

* @todo think about replacing sequential fetch function calls with requires calls * @param {string} _to * @param {string} from * @return {object}

(_to, from)

   * @return {object}
   */
  function fetch(_to, from) {
    // getting absolute path to the processing file
    const filename = /[^\\/?%*:|"<>.]/i.test(_to[0])
      ? require.resolve(_to)
      : resolve(dirname(from), _to);

    // checking cache
    let tokens = tokensByFile[filename];
    if (tokens) {
      debugFetch(`${filename} → cache`);
      debugFetch(tokens);
      return tokens;
    }

    const source = preprocessCss(readFileSync(filename, 'utf8'), filename);
    // https://github.com/postcss/postcss/blob/master/docs/api.md#processorprocesscss-opts
    const lazyResult = runner.process(source, assign({}, processorOpts, {from: filename}));

    // https://github.com/postcss/postcss/blob/master/docs/api.md#lazywarnings
    lazyResult.warnings().forEach(message => console.warn(message.text));

    tokens = lazyResult.root.exports || {};

    if (!debugMode)
      // updating cache
      tokensByFile[filename] = tokens;
    else
      // clearing cache in development mode
      delete require.cache[filename];

    if (processCss)
      processCss(lazyResult.css, filename);

    debugFetch(`${filename} → fs`);
    debugFetch(tokens);

    return tokens;
  }

  const isException = buildExceptionChecker(ignore);