serve-spm/lib/parse.js

SPM middleware for debug.

'use strict';

var extname = require('path').extname;
var readFile = require('fs').readFileSync;
var exists = require('fs').existsSync;
var urlparse = require('url').parse;
var File = require('vinyl');
var debug = require('debug')('serve-spm:parse');
var rules = require('./rules');
var stat = require('fs').statSync;

/*
  Match local file from request url

  url: request url
  opt
  - pkg: a father package
  - rules: custom rules
*/

module.exports = function parse(url, opt) {
  debug('find file of url %s in %s', url, opt.rootPkg.dest);

  var myRules = Array.isArray(opt.rules) ? opt.rules.concat(rules) : rules;
  url = urlparse(url);

  /*
    return a gulp File(vinyl) with some custom properties

    - wrap: whether code should be wrapped by define
    - url: request url Object parsed by `url`
    - pkg: a father package
  */
  var file = findFile(url, opt.pkg, opt.rootPkg, myRules);
  if (!file) return;

  // wrap define by default, except for
  // 1. has ?nowrap in url
  // 2. specified in rules
  if (hasNoWrap(url)) {
    file.wrap = false;
  } else if (typeof file.wrap !== 'boolean') {
    file.wrap = true;
  }

  file.url = url;
  file.pkg = opt.pkg;
  return file;
};

function hasNoWrap(url) {
  var search = url.search;
  return search && search.indexOf('nowrap') > -1;
}

function findFile(url, pkg, rootPkg, rules) {
  for (var i in rules) {
    debug('find file from rule[%s]', i);
    var rule = rules[i];
    var ret = rule(url, pkg, rootPkg) || {};
    debug('rule result path: %s, wrap: %s', ret.path, ret.wrap);

    // ignore when no result or result is invalid
    if (!ret.path) {
      continue;
    }

    // check filepath exists
    var filepath = testFile(ret.path);

    // check directory
    if (filepath && stat(filepath).isDirectory()) {
      return;
    }

    if (filepath) {
      debug('matched %s -> %s on rule[%s]', url.pathname, filepath, i);
      var file = new File({
        base: pkg.dest,
        path: filepath,
        contents: readFile(filepath)
      });
      file.wrap = ret.wrap;
      return file;
    }
  }
}

function testFile(filepath) {
  if (exists(filepath)) return filepath;

  var file;

  // a.css.js$ -> a.css
  // a.tpl.js$ -> a.tpl
  // ...
  if (/\.[a-z]+\.js$/.test(filepath)) {
    file = filepath.slice(0, -3);
    if (exists(file)) return file;
  }

  // a.js$ -> a.coffee
  if (extname(filepath) === '.js') {
    file = filepath.replace(/\.js$/, '.coffee');
    if (exists(file)) return file;
  }

  // a.css$ -> a.less
  // a.css$ -> a.scss, a.sass
  // a.css$ -> a.styl
  if (extname(filepath) === '.css') {
    file = filepath.replace(/\.css$/, '.less');
    if (exists(file)) return file;

    // file = filepath.replace(/\.css$/, '.scss');
    // if (exists(file)) return file;

    // file = filepath.replace(/\.css$/, '.sass');
    // if (exists(file)) return file;

    // file = filepath.replace(/\.css$/, '.styl');
    // if (exists(file)) return file;
  }
}