haste-resolver/lib/utils/extractRequires.js

Haste Resolver

/**
 * Copyright (c) 2015-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */
'use strict';

var replacePatterns = require('./replacePatterns');

/**
 * Extract all required modules from a `code` string.
 */
var blockCommentRe = /\/\*(.|\n)*?\*\//g;
var lineCommentRe = /\/\/.+(\n|$)/g;
function extractRequires(code) {
  var cache = Object.create(null);
  var deps = {
    sync: []
  };

  var addDependency = function addDependency(dep) {
    if (!cache[dep]) {
      cache[dep] = true;
      deps.sync.push(dep);
    }
  };

  code = code.replace(blockCommentRe, '').replace(lineCommentRe, '')
  // Parse the sync dependencies this module has. When the module is
  // required, all it's sync dependencies will be loaded into memory.
  // Sync dependencies can be defined either using `require` or the ES6
  // `import` or `export` syntaxes:
  //   var dep1 = require('dep1');
  .replace(replacePatterns.IMPORT_RE, function (match, pre, quot, dep, post) {
    addDependency(dep);
    return match;
  }).replace(replacePatterns.EXPORT_RE, function (match, pre, quot, dep, post) {
    addDependency(dep);
    return match;
  }).replace(replacePatterns.REQUIRE_RE, function (match, pre, quot, dep, post) {
    addDependency(dep);
    return match;
  });

  return { code: code, deps: deps };
}

module.exports = extractRequires;