co-mocha/co-mocha.js

Enable support for generators in Mocha tests

(function(f){if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=f()}else if(typeof define==="function"&&define.amd){define([],f)}else{var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.coMocha = f()}})(function(){var define,module,exports;return (function(){function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s}return e})()({1:[function(require,module,exports){
var co = require('co')
var isGenFn = require('is-generator').fn

/**
 * Export `co-mocha`.
 */
module.exports = coMocha

/**
 * Monkey patch the mocha instance with generator support.
 *
 * @param {Function} mocha
 */
function coMocha (mocha) {
  // Avoid loading `co-mocha` twice.
  if (!mocha || mocha._coMochaIsLoaded) {
    return
  }

  var Runnable = mocha.Runnable
  var run = Runnable.prototype.run

  /**
   * Override the Mocha function runner and enable generator support with co.
   *
   * @param {Function} fn
   */
  Runnable.prototype.run = function (fn) {
    var oldFn = this.fn

    if (isGenFn(oldFn)) {
      this.fn = co.wrap(oldFn)

      // Replace `toString` to output the original function contents.
      this.fn.toString = function () {
        // https://github.com/mochajs/mocha/blob/7493bca76662318183e55294e906a4107433e20e/lib/utils.js#L251
        return Function.prototype.toString.call(oldFn)
          .replace(/^function *\* *\(.*\)\s*{/, 'function () {')
      }
    }

    return run.call(this, fn)
  }

  mocha._coMochaIsLoaded = true
}

/**
 * Find active node mocha instances.
 *
 * @return {Array}
 */
function findNodeJSMocha () {
  var children = require.cache || {}

  return Object.keys(children)
    .filter(function (child) {
      var val = children[child].exports
      return typeof val === 'function' && val.name === 'Mocha'
    })
    .map(function (child) {
      return children[child].exports
    })
}

// Attempt to automatically monkey patch available mocha instances.
var modules = typeof window === 'undefined' ? findNodeJSMocha() : [window.Mocha]

modules.forEach(coMocha)

},{"co":2,"is-generator":3}],2:[function(require,module,exports){

/**
 * slice() reference.
 */

var slice = Array.prototype.slice;

/**
 * Expose `co`.
 */

module.exports = co['default'] = co.co = co;

/**
 * Wrap the given generator `fn` into a
 * function that returns a promise.
 * This is a separate function so that
 * every `co()` call doesn't create a new,
 * unnecessary closure.
 *
 * @param {GeneratorFunction} fn
 * @return {Function}
 * @api public
 */

co.wrap = function (fn) {
  createPromise.__generatorFunction__ = fn;
  return createPromise;
  function createPromise() {
    return co.call(this, fn.apply(this, arguments));
  }
};

/**
 * Execute the generator function or a generator
 * and return a promise.
 *
 * @param {Function} fn
 * @return {Promise}
 * @api public
 */

function co(gen) {
  var ctx = this;
  var args = slice.call(arguments, 1)

  // we wrap everything in a promise to avoid promise chaining,
  // which leads to memory leak errors.
  // see https://github.com/tj/co/issues/180
  return new Promise(function(resolve, reject) {
    if (typeof gen === 'function') gen = gen.apply(ctx, args);
    if (!gen || typeof gen.next !== 'function') return resolve(gen);

    onFulfilled();

    /**
     * @param {Mixed} res
     * @return {Promise}
     * @api private
     */

    function onFulfilled(res) {
      var ret;
      try {
        ret = gen.next(res);
      } catch (e) {
        return reject(e);
      }
      next(ret);
    }

    /**
     * @param {Error} err
     * @return {Promise}
     * @api private
     */

    function onRejected(err) {
      var ret;
      try {
        ret = gen.throw(err);
      } catch (e) {
        return reject(e);
      }
      next(ret);
    }

    /**
     * Get the next value in the generator,
     * return a promise.
     *
     * @param {Object} ret
     * @return {Promise}
     * @api private
     */

    function next(ret) {
      if (ret.done) return resolve(ret.value);
      var value = toPromise.call(ctx, ret.value);
      if (value && isPromise(value)) return value.then(onFulfilled, onRejected);
      return onRejected(new TypeError('You may only yield a function, promise, generator, array, or object, '
        + 'but the following object was passed: "' + String(ret.value) + '"'));
    }
  });
}

/**
 * Convert a `yield`ed value into a promise.
 *
 * @param {Mixed} obj
 * @return {Promise}
 * @api private
 */

function toPromise(obj) {
  if (!obj) return obj;
  if (isPromise(obj)) return obj;
  if (isGeneratorFunction(obj) || isGenerator(obj)) return co.call(this, obj);
  if ('function' == typeof obj) return thunkToPromise.call(this, obj);
  if (Array.isArray(obj)) return arrayToPromise.call(this, obj);
  if (isObject(obj)) return objectToPromise.call(this, obj);
  return obj;
}

/**
 * Convert a thunk to a promise.
 *
 * @param {Function}
 * @return {Promise}
 * @api private
 */

function thunkToPromise(fn) {
  var ctx = this;
  return new Promise(function (resolve, reject) {
    fn.call(ctx, function (err, res) {
      if (err) return reject(err);
      if (arguments.length > 2) res = slice.call(arguments, 1);
      resolve(res);
    });
  });
}

/**
 * Convert an array of "yieldables" to a promise.
 * Uses `Promise.all()` internally.
 *
 * @param {Array} obj
 * @return {Promise}
 * @api private
 */

function arrayToPromise(obj) {
  return Promise.all(obj.map(toPromise, this));
}

/**
 * Convert an object of "yieldables" to a promise.
 * Uses `Promise.all()` internally.
 *
 * @param {Object} obj
 * @return {Promise}
 * @api private
 */

function objectToPromise(obj){
  var results = new obj.constructor();
  var keys = Object.keys(obj);
  var promises = [];
  for (var i = 0; i < keys.length; i++) {
    var key = keys[i];
    var promise = toPromise.call(this, obj[key]);
    if (promise && isPromise(promise)) defer(promise, key);
    else results[key] = obj[key];
  }
  return Promise.all(promises).then(function () {
    return results;
  });

  function defer(promise, key) {
    // predefine the key in the result
    results[key] = undefined;
    promises.push(promise.then(function (res) {
      results[key] = res;
    }));
  }
}

/**
 * Check if `obj` is a promise.
 *
 * @param {Object} obj
 * @return {Boolean}
 * @api private
 */

function isPromise(obj) {
  return 'function' == typeof obj.then;
}

/**
 * Check if `obj` is a generator.
 *
 * @param {Mixed} obj
 * @return {Boolean}
 * @api private
 */

function isGenerator(obj) {
  return 'function' == typeof obj.next && 'function' == typeof obj.throw;
}

/**
 * Check if `obj` is a generator function.
 *
 * @param {Mixed} obj
 * @return {Boolean}
 * @api private
 */
function isGeneratorFunction(obj) {
  var constructor = obj.constructor;
  if (!constructor) return false;
  if ('GeneratorFunction' === constructor.name || 'GeneratorFunction' === constructor.displayName) return true;
  return isGenerator(constructor.prototype);
}

/**
 * Check for plain object.
 *
 * @param {Mixed} val
 * @return {Boolean}
 * @api private
 */

function isObject(val) {
  return Object == val.constructor;
}

},{}],3:[function(require,module,exports){
/**
 * Export generator function checks.
 */
module.exports = isGenerator
module.exports.fn = isGeneratorFunction

/**
 * Check whether an object is a generator.
 *
 * @param  {Object}  obj
 * @return {Boolean}
 */
function isGenerator (obj) {
  return obj &&
    typeof obj.next === 'function' &&
    typeof obj.throw === 'function'
}

/**
 * Check whether a function is generator.
 *
 * @param  {Function} fn
 * @return {Boolean}
 */
function isGeneratorFunction (fn) {
  return typeof fn === 'function' &&
    fn.constructor &&
    fn.constructor.name === 'GeneratorFunction'
}

},{}]},{},[1])(1)
});