pouchdb.live-find.js

(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})({1:[function(require,module,exports){
'use strict';
var collate = require('pouchdb-collate').collate;
var selectorCore = require('pouchdb-selector-core');
var filterInMemoryFields = selectorCore.filterInMemoryFields;
var utils = require('./utils');
var compare = selectorCore.compare;
var getUserFields = utils.getUserFields;
var getKey = selectorCore.getKey;
var getValue = selectorCore.getValue;
var parseField = selectorCore.parseField;

exports.memoryFilter = function(docs, requestDef) {
  var userFieldsRes = getUserFields(requestDef.selector, requestDef.sort);
  var userFields = userFieldsRes.fields;
  var rows = docs.map(function(doc) { return {doc: doc}; });
  return filterInMemoryFields(rows, requestDef, userFields)
    .map(function(row) {
      return row.doc;
    });
};

// create a comparator based on the sort object
exports.createFieldSorter = function(sort) {

  function getFieldValuesAsArray(doc) {
    return sort.map(function (sorting) {
      var fieldName = getKey(sorting);
      var parsedField = parseField(fieldName);
      var docFieldValue = getFieldFromDoc(doc, parsedField);
      return docFieldValue;
    });
  }

  var directions = sort.map(function(sorting) {
    if (typeof sorting !== 'string' &&
      getValue(sorting) === 'desc') {
      return -1;
    }
    return 1;
  });

  return function (aRow, bRow) {
    var aFieldValues = getFieldValuesAsArray(aRow);
    var bFieldValues = getFieldValuesAsArray(bRow);
    for(var i=0, len=directions.length; i<len; i++) {
      var collation = collate(aFieldValues[i], bFieldValues[i]);
      if (collation !== 0) {
        return collation * directions[i];
      }
    }
    // this is what mango seems to do
    return compare(aRow._id, bRow._id) * directions[0];
  };
};

function getFieldFromDoc(doc, parsedField) {
  var value = doc;
  for (var i = 0, len = parsedField.length; i < len; i++) {
    var key = parsedField[i];
    value = value[key];
    if (!value) {
      break;
    }
  }
  return value;
}
},{"./utils":3,"pouchdb-collate":9,"pouchdb-selector-core":13}],2:[function(require,module,exports){
'use strict';
var EventEmitter = require('events');
var helpers = require('./helpers');
var collate = require('pouchdb-collate').collate;
var selectorCore = require('pouchdb-selector-core');
var utils = require('./utils');
var getValue = selectorCore.getValue;
var massageSelector = selectorCore.massageSelector;
var massageSort = utils.massageSort;

function liveFind(requestDef) {

  if(typeof this.find !== 'function') {
    throw new Error('ERROR: PouchDB Find is a requirement for LiveFind and must be loaded first.');
  }

  var db = this;
  var cancelled = false;
  var lookup = {};
  var emitter = new EventEmitter();
  var docList = [];
  var aggregate = requestDef.aggregate || false;

  // Normalize the request options
  var fields = requestDef.fields;
  var stripId = false, stripRev = false;
  if(fields) {
    // _id is a necessary field to process the docs
    if(fields.indexOf('_id') === -1) {
      fields.unshift('_id');
      stripId = true;
    }
    // We need the _rev to sort out changes but can strip it later
    if(fields.indexOf('_rev') === -1) {
      fields.push('_rev');
      stripRev = true;
    }
  }
  var selector;
  if(requestDef.selector) {
    selector = massageSelector(requestDef.selector);
  }
  var sort, sortFn;
  if(requestDef.sort) {
    sort = massageSort(requestDef.sort);
    sortFn = helpers.createFieldSorter(sort);
  }
  var skip = parseInt(requestDef.skip, 10) || 0;
  var limit = parseInt(requestDef.limit, 10) || 0;
  var findRequest = {
    selector: selector,
    // sort: sort,
    fields: fields
  };

  var ready = db.find(findRequest)
    .then(function(results) {
      results.docs.forEach(function(doc) {
        addResult(doc);
      });
      emitter.emit('ready');
    })
    .catch(function(err) {
      emitter.emit('error', err);
      cancel();
      throw err;
    });

  // We will use just one change listener for all live queries.
  // We need to keep track of how many queries are running.
  // When the last live query finishes we will cancel the listener.
  if(!db._changeListener) {
    listen();
  }
  if(!db._activeQueries) {
    db._activeQueries = 1;
  } else {
    db._activeQueries++;
  }

  db._changeListener
    .on('change', changeHandler)
    .on('error', errorHandler);

  emitter.cancel = cancel;
  // Bind the `find` query promise to our emitter object
  // so we know when the initial query is done and can catch errors
  emitter.then = ready.then.bind(ready);
  emitter.catch = ready.catch.bind(ready);

  emitter.sort = function(list) {
    if(!sort) {
      return list;
    }
    return sortList(list);
  };

  emitter.paginate = paginate;

  function changeHandler(change) {
    ready.then(function() {
      if(change.doc) {
        processChange(change.doc);
      }
    });
  }

  function errorHandler(err) {
    emitter.emit('error', err);
  }

  function cancel() {
    if(!cancelled) {
      db._activeQueries --;
      if(!db._activeQueries) {
        db._changeListener.cancel();
        delete db._changeListener;
      } else {
        db._changeListener.removeListener('change', changeHandler);
        db._changeListener.removeListener('error', errorHandler);
      }
      emitter.emit('cancelled');
      emitter.removeAllListeners();
      cancelled = true;
    }
  }

  function listen() {
    db._changeListener = db.changes({live: true, retry: true, include_docs: true, since: 'now'});
  }

  function filterDoc(doc) {
    var result = helpers.memoryFilter([doc], {selector: selector});
    if(result.length) {
      return result[0];
    }
    return null;
  }

  function pickFields(doc) {
    if (fields) {
      var output = utils.pick(doc, fields);
      if(stripId) {
        delete output._id;
      }
      if(stripRev) {
        delete output._rev;
      }
      return output;
    }
    return doc;
  }

  // This processes the initial results of the query
  function addResult(doc) {
    lookup[doc._id] = doc._rev;
    var id = doc._id;
    var rev = doc._rev;
    if(stripId) {
      delete doc._id;
    }
    if(stripRev) {
      delete doc._rev;
    }
    return addAction(doc, id, rev);
  }

  function processChange(doc) {
    // Don't fire an update if this rev has already been processed
    if(lookup[doc._id] === doc._rev) {
      // console.warn('A change was fired twice. This shouldn\'t happen.');
      return;
    }
    var id = doc._id;
    var rev = doc._rev;
    if(doc._deleted && lookup[id]) {
      lookup[id] = null;
      return removeAction({_id: id, _rev: rev, deleted: true}, id, rev);
    }
    var outputDoc = filterDoc(doc);
    if(!outputDoc && lookup[id]) {
      lookup[id] = null;
      return removeAction({_id: id, _rev: rev}, id, rev);
    }
    if(outputDoc && !lookup[id]) {
      lookup[id] = rev;
      return addAction(pickFields(outputDoc), id, rev);
    }
    if(outputDoc && lookup[id]) {
      lookup[id] = rev;
      return updateAction(pickFields(outputDoc), id, rev);
    }
  }

  function removeAction(doc, id, rev) {
    var list;
    if(aggregate) {
      docList = docList.filter(function(item) {
        return item._id !== doc._id;
      });
      list = formatList(docList);
    }
    emitter.emit('update', { action: 'REMOVE', id: id, rev: rev, doc: doc }, list);
  }

  function addAction(doc, id, rev) {
    var list;
    if(aggregate) {
      docList = docList.concat(doc);
      list = formatList(docList);
    }
    emitter.emit('update', { action: 'ADD', id: id, rev: rev, doc: doc }, list);
  }

  function updateAction(doc, id, rev) {
    var list;
    if(aggregate) {
      docList = docList.map(function(item) {
        return item._id === doc._id ? doc : item;
      });
      list = formatList(docList);
    }
    emitter.emit('update', { action: 'UPDATE', id: id, rev: rev, doc: doc }, list);
  }

  /* function sortList(list) {
    list = list.sort(sortFn);
    if (typeof sort[0] !== 'string' &&
      getValue(sort[0]) === 'desc') {
      list = list.reverse();
    }
    return list;
  } */

  function sortList(list) {
    return list.sort(sortFn);
  }

  // Applies sort, skip, and limit to a list
  function formatList(list) {
    if(sort) {
      list = sortList(list);
    }
    if(skip || limit) {
      if(limit) {
        list = list.slice(skip, skip + limit);
      } else {
        list = list.slice(skip);
      }
    }
    return list;
  }

  function paginate(options) {
    if(!aggregate || !options || typeof options !== 'object') {
      return;
    }
    if(options.skip != null) {
      skip = parseInt(options.skip, 10) || 0;
    }
    if(options.limit != null) {
      limit = parseInt(options.limit, 10) || 0;
    }
    if(options.sort && options.sort instanceof Array) {
      sort = massageSort(options.sort);
      sortFn = helpers.createFieldSorter(sort);
    }
    return formatList(docList);
  }

  return emitter;

}

exports.liveFind = liveFind;

if (typeof window !== 'undefined' && window.PouchDB) {
  window.PouchDB.plugin(exports);
}
},{"./helpers":1,"./utils":3,"events":5,"pouchdb-collate":9,"pouchdb-selector-core":13}],3:[function(require,module,exports){
'use strict';

var selectorCore = require('pouchdb-selector-core');
var getKey = selectorCore.getKey;
var getFieldFromDoc = selectorCore.getFieldFromDoc;
var setFieldInDoc = selectorCore.setFieldInDoc;
var parseField = selectorCore.parseField;

// determine the maximum number of fields
// we're going to need to query, e.g. if the user
// has selection ['a'] and sorting ['a', 'b'], then we
// need to use the longer of the two: ['a', 'b']
exports.getUserFields = function(selector, sort) {
  var selectorFields = Object.keys(selector);
  var sortFields = sort? sort.map(getKey) : [];
  var userFields;
  if (selectorFields.length >= sortFields.length) {
    userFields = selectorFields;
  } else {
    userFields = sortFields;
  }

  if (sortFields.length === 0) {
    return {
      fields: userFields
    };
  }

  // sort according to the user's preferred sorting
  userFields = userFields.sort(function (left, right) {
    var leftIdx = sortFields.indexOf(left);
    if (leftIdx === -1) {
      leftIdx = Number.MAX_VALUE;
    }
    var rightIdx = sortFields.indexOf(right);
    if (rightIdx === -1) {
      rightIdx = Number.MAX_VALUE;
    }
    return leftIdx < rightIdx ? -1 : leftIdx > rightIdx ? 1 : 0;
  });

  return {
    fields: userFields,
    sortOrder: sort.map(getKey)
  };
};

// normalize the "sort" value
exports.massageSort = function(sort) {
  if (!Array.isArray(sort)) {
    throw new Error('invalid sort json - should be an array');
  }
  return sort.map(function (sorting) {
    if (typeof sorting === 'string') {
      var obj = {};
      obj[sorting] = 'asc';
      return obj;
    } else {
      return sorting;
    }
  });
};

// Selects a list of fields defined in dot notation from one doc
// and copies them to a new doc. Like underscore _.pick but supports nesting.
exports.pick = function(obj, arr) {
  var res = {};
  for (var i = 0, len = arr.length; i < len; i++) {
    var parsedField = parseField(arr[i]);
    var value = getFieldFromDoc(obj, parsedField);
    if (typeof value !== 'undefined') {
      setFieldInDoc(res, parsedField, value);
    }
  }
  return res;
};

},{"pouchdb-selector-core":13}],4:[function(require,module,exports){
'use strict';

module.exports = argsArray;

function argsArray(fun) {
  return function () {
    var len = arguments.length;
    if (len) {
      var args = [];
      var i = -1;
      while (++i < len) {
        args[i] = arguments[i];
      }
      return fun.call(this, args);
    } else {
      return fun.call(this, []);
    }
  };
}
},{}],5:[function(require,module,exports){
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

function EventEmitter() {
  this._events = this._events || {};
  this._maxListeners = this._maxListeners || undefined;
}
module.exports = EventEmitter;

// Backwards-compat with node 0.10.x
EventEmitter.EventEmitter = EventEmitter;

EventEmitter.prototype._events = undefined;
EventEmitter.prototype._maxListeners = undefined;

// By default EventEmitters will print a warning if more than 10 listeners are
// added to it. This is a useful default which helps finding memory leaks.
EventEmitter.defaultMaxListeners = 10;

// Obviously not all Emitters should be limited to 10. This function allows
// that to be increased. Set to zero for unlimited.
EventEmitter.prototype.setMaxListeners = function(n) {
  if (!isNumber(n) || n < 0 || isNaN(n))
    throw TypeError('n must be a positive number');
  this._maxListeners = n;
  return this;
};

EventEmitter.prototype.emit = function(type) {
  var er, handler, len, args, i, listeners;

  if (!this._events)
    this._events = {};

  // If there is no 'error' event listener then throw.
  if (type === 'error') {
    if (!this._events.error ||
        (isObject(this._events.error) && !this._events.error.length)) {
      er = arguments[1];
      if (er instanceof Error) {
        throw er; // Unhandled 'error' event
      } else {
        // At least give some kind of context to the user
        var err = new Error('Uncaught, unspecified "error" event. (' + er + ')');
        err.context = er;
        throw err;
      }
    }
  }

  handler = this._events[type];

  if (isUndefined(handler))
    return false;

  if (isFunction(handler)) {
    switch (arguments.length) {
      // fast cases
      case 1:
        handler.call(this);
        break;
      case 2:
        handler.call(this, arguments[1]);
        break;
      case 3:
        handler.call(this, arguments[1], arguments[2]);
        break;
      // slower
      default:
        args = Array.prototype.slice.call(arguments, 1);
        handler.apply(this, args);
    }
  } else if (isObject(handler)) {
    args = Array.prototype.slice.call(arguments, 1);
    listeners = handler.slice();
    len = listeners.length;
    for (i = 0; i < len; i++)
      listeners[i].apply(this, args);
  }

  return true;
};

EventEmitter.prototype.addListener = function(type, listener) {
  var m;

  if (!isFunction(listener))
    throw TypeError('listener must be a function');

  if (!this._events)
    this._events = {};

  // To avoid recursion in the case that type === "newListener"! Before
  // adding it to the listeners, first emit "newListener".
  if (this._events.newListener)
    this.emit('newListener', type,
              isFunction(listener.listener) ?
              listener.listener : listener);

  if (!this._events[type])
    // Optimize the case of one listener. Don't need the extra array object.
    this._events[type] = listener;
  else if (isObject(this._events[type]))
    // If we've already got an array, just append.
    this._events[type].push(listener);
  else
    // Adding the second element, need to change to array.
    this._events[type] = [this._events[type], listener];

  // Check for listener leak
  if (isObject(this._events[type]) && !this._events[type].warned) {
    if (!isUndefined(this._maxListeners)) {
      m = this._maxListeners;
    } else {
      m = EventEmitter.defaultMaxListeners;
    }

    if (m && m > 0 && this._events[type].length > m) {
      this._events[type].warned = true;
      console.error('(node) warning: possible EventEmitter memory ' +
                    'leak detected. %d listeners added. ' +
                    'Use emitter.setMaxListeners() to increase limit.',
                    this._events[type].length);
      if (typeof console.trace === 'function') {
        // not supported in IE 10
        console.trace();
      }
    }
  }

  return this;
};

EventEmitter.prototype.on = EventEmitter.prototype.addListener;

EventEmitter.prototype.once = function(type, listener) {
  if (!isFunction(listener))
    throw TypeError('listener must be a function');

  var fired = false;

  function g() {
    this.removeListener(type, g);

    if (!fired) {
      fired = true;
      listener.apply(this, arguments);
    }
  }

  g.listener = listener;
  this.on(type, g);

  return this;
};

// emits a 'removeListener' event iff the listener was removed
EventEmitter.prototype.removeListener = function(type, listener) {
  var list, position, length, i;

  if (!isFunction(listener))
    throw TypeError('listener must be a function');

  if (!this._events || !this._events[type])
    return this;

  list = this._events[type];
  length = list.length;
  position = -1;

  if (list === listener ||
      (isFunction(list.listener) && list.listener === listener)) {
    delete this._events[type];
    if (this._events.removeListener)
      this.emit('removeListener', type, listener);

  } else if (isObject(list)) {
    for (i = length; i-- > 0;) {
      if (list[i] === listener ||
          (list[i].listener && list[i].listener === listener)) {
        position = i;
        break;
      }
    }

    if (position < 0)
      return this;

    if (list.length === 1) {
      list.length = 0;
      delete this._events[type];
    } else {
      list.splice(position, 1);
    }

    if (this._events.removeListener)
      this.emit('removeListener', type, listener);
  }

  return this;
};

EventEmitter.prototype.removeAllListeners = function(type) {
  var key, listeners;

  if (!this._events)
    return this;

  // not listening for removeListener, no need to emit
  if (!this._events.removeListener) {
    if (arguments.length === 0)
      this._events = {};
    else if (this._events[type])
      delete this._events[type];
    return this;
  }

  // emit removeListener for all listeners on all events
  if (arguments.length === 0) {
    for (key in this._events) {
      if (key === 'removeListener') continue;
      this.removeAllListeners(key);
    }
    this.removeAllListeners('removeListener');
    this._events = {};
    return this;
  }

  listeners = this._events[type];

  if (isFunction(listeners)) {
    this.removeListener(type, listeners);
  } else if (listeners) {
    // LIFO order
    while (listeners.length)
      this.removeListener(type, listeners[listeners.length - 1]);
  }
  delete this._events[type];

  return this;
};

EventEmitter.prototype.listeners = function(type) {
  var ret;
  if (!this._events || !this._events[type])
    ret = [];
  else if (isFunction(this._events[type]))
    ret = [this._events[type]];
  else
    ret = this._events[type].slice();
  return ret;
};

EventEmitter.prototype.listenerCount = function(type) {
  if (this._events) {
    var evlistener = this._events[type];

    if (isFunction(evlistener))
      return 1;
    else if (evlistener)
      return evlistener.length;
  }
  return 0;
};

EventEmitter.listenerCount = function(emitter, type) {
  return emitter.listenerCount(type);
};

function isFunction(arg) {
  return typeof arg === 'function';
}

function isNumber(arg) {
  return typeof arg === 'number';
}

function isObject(arg) {
  return typeof arg === 'object' && arg !== null;
}

function isUndefined(arg) {
  return arg === void 0;
}

},{}],6:[function(require,module,exports){
(function (global){
'use strict';
var Mutation = global.MutationObserver || global.WebKitMutationObserver;

var scheduleDrain;

{
  if (Mutation) {
    var called = 0;
    var observer = new Mutation(nextTick);
    var element = global.document.createTextNode('');
    observer.observe(element, {
      characterData: true
    });
    scheduleDrain = function () {
      element.data = (called = ++called % 2);
    };
  } else if (!global.setImmediate && typeof global.MessageChannel !== 'undefined') {
    var channel = new global.MessageChannel();
    channel.port1.onmessage = nextTick;
    scheduleDrain = function () {
      channel.port2.postMessage(0);
    };
  } else if ('document' in global && 'onreadystatechange' in global.document.createElement('script')) {
    scheduleDrain = function () {

      // Create a <script> element; its readystatechange event will be fired asynchronously once it is inserted
      // into the document. Do so, thus queuing up the task. Remember to clean up once it's been called.
      var scriptEl = global.document.createElement('script');
      scriptEl.onreadystatechange = function () {
        nextTick();

        scriptEl.onreadystatechange = null;
        scriptEl.parentNode.removeChild(scriptEl);
        scriptEl = null;
      };
      global.document.documentElement.appendChild(scriptEl);
    };
  } else {
    scheduleDrain = function () {
      setTimeout(nextTick, 0);
    };
  }
}

var draining;
var queue = [];
//named nextTick for less confusing stack traces
function nextTick() {
  draining = true;
  var i, oldQueue;
  var len = queue.length;
  while (len) {
    oldQueue = queue;
    queue = [];
    i = -1;
    while (++i < len) {
      oldQueue[i]();
    }
    len = queue.length;
  }
  draining = false;
}

module.exports = immediate;
function immediate(task) {
  if (queue.push(task) === 1 && !draining) {
    scheduleDrain();
  }
}

}).call(this,typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{}],7:[function(require,module,exports){
if (typeof Object.create === 'function') {
  // implementation from standard node.js 'util' module
  module.exports = function inherits(ctor, superCtor) {
    ctor.super_ = superCtor
    ctor.prototype = Object.create(superCtor.prototype, {
      constructor: {
        value: ctor,
        enumerable: false,
        writable: true,
        configurable: true
      }
    });
  };
} else {
  // old school shim for old browsers
  module.exports = function inherits(ctor, superCtor) {
    ctor.super_ = superCtor
    var TempCtor = function () {}
    TempCtor.prototype = superCtor.prototype
    ctor.prototype = new TempCtor()
    ctor.prototype.constructor = ctor
  }
}

},{}],8:[function(require,module,exports){
'use strict';
var immediate = require('immediate');

/* istanbul ignore next */
function INTERNAL() {}

var handlers = {};

var REJECTED = ['REJECTED'];
var FULFILLED = ['FULFILLED'];
var PENDING = ['PENDING'];

module.exports = Promise;

function Promise(resolver) {
  if (typeof resolver !== 'function') {
    throw new TypeError('resolver must be a function');
  }
  this.state = PENDING;
  this.queue = [];
  this.outcome = void 0;
  if (resolver !== INTERNAL) {
    safelyResolveThenable(this, resolver);
  }
}

Promise.prototype["catch"] = function (onRejected) {
  return this.then(null, onRejected);
};
Promise.prototype.then = function (onFulfilled, onRejected) {
  if (typeof onFulfilled !== 'function' && this.state === FULFILLED ||
    typeof onRejected !== 'function' && this.state === REJECTED) {
    return this;
  }
  var promise = new this.constructor(INTERNAL);
  if (this.state !== PENDING) {
    var resolver = this.state === FULFILLED ? onFulfilled : onRejected;
    unwrap(promise, resolver, this.outcome);
  } else {
    this.queue.push(new QueueItem(promise, onFulfilled, onRejected));
  }

  return promise;
};
function QueueItem(promise, onFulfilled, onRejected) {
  this.promise = promise;
  if (typeof onFulfilled === 'function') {
    this.onFulfilled = onFulfilled;
    this.callFulfilled = this.otherCallFulfilled;
  }
  if (typeof onRejected === 'function') {
    this.onRejected = onRejected;
    this.callRejected = this.otherCallRejected;
  }
}
QueueItem.prototype.callFulfilled = function (value) {
  handlers.resolve(this.promise, value);
};
QueueItem.prototype.otherCallFulfilled = function (value) {
  unwrap(this.promise, this.onFulfilled, value);
};
QueueItem.prototype.callRejected = function (value) {
  handlers.reject(this.promise, value);
};
QueueItem.prototype.otherCallRejected = function (value) {
  unwrap(this.promise, this.onRejected, value);
};

function unwrap(promise, func, value) {
  immediate(function () {
    var returnValue;
    try {
      returnValue = func(value);
    } catch (e) {
      return handlers.reject(promise, e);
    }
    if (returnValue === promise) {
      handlers.reject(promise, new TypeError('Cannot resolve promise with itself'));
    } else {
      handlers.resolve(promise, returnValue);
    }
  });
}

handlers.resolve = function (self, value) {
  var result = tryCatch(getThen, value);
  if (result.status === 'error') {
    return handlers.reject(self, result.value);
  }
  var thenable = result.value;

  if (thenable) {
    safelyResolveThenable(self, thenable);
  } else {
    self.state = FULFILLED;
    self.outcome = value;
    var i = -1;
    var len = self.queue.length;
    while (++i < len) {
      self.queue[i].callFulfilled(value);
    }
  }
  return self;
};
handlers.reject = function (self, error) {
  self.state = REJECTED;
  self.outcome = error;
  var i = -1;
  var len = self.queue.length;
  while (++i < len) {
    self.queue[i].callRejected(error);
  }
  return self;
};

function getThen(obj) {
  // Make sure we only access the accessor once as required by the spec
  var then = obj && obj.then;
  if (obj && (typeof obj === 'object' || typeof obj === 'function') && typeof then === 'function') {
    return function appyThen() {
      then.apply(obj, arguments);
    };
  }
}

function safelyResolveThenable(self, thenable) {
  // Either fulfill, reject or reject with error
  var called = false;
  function onError(value) {
    if (called) {
      return;
    }
    called = true;
    handlers.reject(self, value);
  }

  function onSuccess(value) {
    if (called) {
      return;
    }
    called = true;
    handlers.resolve(self, value);
  }

  function tryToUnwrap() {
    thenable(onSuccess, onError);
  }

  var result = tryCatch(tryToUnwrap);
  if (result.status === 'error') {
    onError(result.value);
  }
}

function tryCatch(func, value) {
  var out = {};
  try {
    out.value = func(value);
    out.status = 'success';
  } catch (e) {
    out.status = 'error';
    out.value = e;
  }
  return out;
}

Promise.resolve = resolve;
function resolve(value) {
  if (value instanceof this) {
    return value;
  }
  return handlers.resolve(new this(INTERNAL), value);
}

Promise.reject = reject;
function reject(reason) {
  var promise = new this(INTERNAL);
  return handlers.reject(promise, reason);
}

Promise.all = all;
function all(iterable) {
  var self = this;
  if (Object.prototype.toString.call(iterable) !== '[object Array]') {
    return this.reject(new TypeError('must be an array'));
  }

  var len = iterable.length;
  var called = false;
  if (!len) {
    return this.resolve([]);
  }

  var values = new Array(len);
  var resolved = 0;
  var i = -1;
  var promise = new this(INTERNAL);

  while (++i < len) {
    allResolver(iterable[i], i);
  }
  return promise;
  function allResolver(value, i) {
    self.resolve(value).then(resolveFromAll, function (error) {
      if (!called) {
        called = true;
        handlers.reject(promise, error);
      }
    });
    function resolveFromAll(outValue) {
      values[i] = outValue;
      if (++resolved === len && !called) {
        called = true;
        handlers.resolve(promise, values);
      }
    }
  }
}

Promise.race = race;
function race(iterable) {
  var self = this;
  if (Object.prototype.toString.call(iterable) !== '[object Array]') {
    return this.reject(new TypeError('must be an array'));
  }

  var len = iterable.length;
  var called = false;
  if (!len) {
    return this.resolve([]);
  }

  var i = -1;
  var promise = new this(INTERNAL);

  while (++i < len) {
    resolver(iterable[i]);
  }
  return promise;
  function resolver(value) {
    self.resolve(value).then(function (response) {
      if (!called) {
        called = true;
        handlers.resolve(promise, response);
      }
    }, function (error) {
      if (!called) {
        called = true;
        handlers.reject(promise, error);
      }
    });
  }
}

},{"immediate":6}],9:[function(require,module,exports){
'use strict';

Object.defineProperty(exports, '__esModule', { value: true });

function pad(str, padWith, upToLength) {
  var padding = '';
  var targetLength = upToLength - str.length;
  /* istanbul ignore next */
  while (padding.length < targetLength) {
    padding += padWith;
  }
  return padding;
}

function padLeft(str, padWith, upToLength) {
  var padding = pad(str, padWith, upToLength);
  return padding + str;
}

var MIN_MAGNITUDE = -324; // verified by -Number.MIN_VALUE
var MAGNITUDE_DIGITS = 3; // ditto
var SEP = ''; // set to '_' for easier debugging 

function collate(a, b) {

  if (a === b) {
    return 0;
  }

  a = normalizeKey(a);
  b = normalizeKey(b);

  var ai = collationIndex(a);
  var bi = collationIndex(b);
  if ((ai - bi) !== 0) {
    return ai - bi;
  }
  switch (typeof a) {
    case 'number':
      return a - b;
    case 'boolean':
      return a < b ? -1 : 1;
    case 'string':
      return stringCollate(a, b);
  }
  return Array.isArray(a) ? arrayCollate(a, b) : objectCollate(a, b);
}

// couch considers null/NaN/Infinity/-Infinity === undefined,
// for the purposes of mapreduce indexes. also, dates get stringified.
function normalizeKey(key) {
  switch (typeof key) {
    case 'undefined':
      return null;
    case 'number':
      if (key === Infinity || key === -Infinity || isNaN(key)) {
        return null;
      }
      return key;
    case 'object':
      var origKey = key;
      if (Array.isArray(key)) {
        var len = key.length;
        key = new Array(len);
        for (var i = 0; i < len; i++) {
          key[i] = normalizeKey(origKey[i]);
        }
      /* istanbul ignore next */
      } else if (key instanceof Date) {
        return key.toJSON();
      } else if (key !== null) { // generic object
        key = {};
        for (var k in origKey) {
          if (origKey.hasOwnProperty(k)) {
            var val = origKey[k];
            if (typeof val !== 'undefined') {
              key[k] = normalizeKey(val);
            }
          }
        }
      }
  }
  return key;
}

function indexify(key) {
  if (key !== null) {
    switch (typeof key) {
      case 'boolean':
        return key ? 1 : 0;
      case 'number':
        return numToIndexableString(key);
      case 'string':
        // We've to be sure that key does not contain \u0000
        // Do order-preserving replacements:
        // 0 -> 1, 1
        // 1 -> 1, 2
        // 2 -> 2, 2
        return key
          .replace(/\u0002/g, '\u0002\u0002')
          .replace(/\u0001/g, '\u0001\u0002')
          .replace(/\u0000/g, '\u0001\u0001');
      case 'object':
        var isArray = Array.isArray(key);
        var arr = isArray ? key : Object.keys(key);
        var i = -1;
        var len = arr.length;
        var result = '';
        if (isArray) {
          while (++i < len) {
            result += toIndexableString(arr[i]);
          }
        } else {
          while (++i < len) {
            var objKey = arr[i];
            result += toIndexableString(objKey) +
                toIndexableString(key[objKey]);
          }
        }
        return result;
    }
  }
  return '';
}

// convert the given key to a string that would be appropriate
// for lexical sorting, e.g. within a database, where the
// sorting is the same given by the collate() function.
function toIndexableString(key) {
  var zero = '\u0000';
  key = normalizeKey(key);
  return collationIndex(key) + SEP + indexify(key) + zero;
}

function parseNumber(str, i) {
  var originalIdx = i;
  var num;
  var zero = str[i] === '1';
  if (zero) {
    num = 0;
    i++;
  } else {
    var neg = str[i] === '0';
    i++;
    var numAsString = '';
    var magAsString = str.substring(i, i + MAGNITUDE_DIGITS);
    var magnitude = parseInt(magAsString, 10) + MIN_MAGNITUDE;
    /* istanbul ignore next */
    if (neg) {
      magnitude = -magnitude;
    }
    i += MAGNITUDE_DIGITS;
    while (true) {
      var ch = str[i];
      if (ch === '\u0000') {
        break;
      } else {
        numAsString += ch;
      }
      i++;
    }
    numAsString = numAsString.split('.');
    if (numAsString.length === 1) {
      num = parseInt(numAsString, 10);
    } else {
      /* istanbul ignore next */
      num = parseFloat(numAsString[0] + '.' + numAsString[1]);
    }
    /* istanbul ignore next */
    if (neg) {
      num = num - 10;
    }
    /* istanbul ignore next */
    if (magnitude !== 0) {
      // parseFloat is more reliable than pow due to rounding errors
      // e.g. Number.MAX_VALUE would return Infinity if we did
      // num * Math.pow(10, magnitude);
      num = parseFloat(num + 'e' + magnitude);
    }
  }
  return {num: num, length : i - originalIdx};
}

// move up the stack while parsing
// this function moved outside of parseIndexableString for performance
function pop(stack, metaStack) {
  var obj = stack.pop();

  if (metaStack.length) {
    var lastMetaElement = metaStack[metaStack.length - 1];
    if (obj === lastMetaElement.element) {
      // popping a meta-element, e.g. an object whose value is another object
      metaStack.pop();
      lastMetaElement = metaStack[metaStack.length - 1];
    }
    var element = lastMetaElement.element;
    var lastElementIndex = lastMetaElement.index;
    if (Array.isArray(element)) {
      element.push(obj);
    } else if (lastElementIndex === stack.length - 2) { // obj with key+value
      var key = stack.pop();
      element[key] = obj;
    } else {
      stack.push(obj); // obj with key only
    }
  }
}

function parseIndexableString(str) {
  var stack = [];
  var metaStack = []; // stack for arrays and objects
  var i = 0;

  /*eslint no-constant-condition: ["error", { "checkLoops": false }]*/
  while (true) {
    var collationIndex = str[i++];
    if (collationIndex === '\u0000') {
      if (stack.length === 1) {
        return stack.pop();
      } else {
        pop(stack, metaStack);
        continue;
      }
    }
    switch (collationIndex) {
      case '1':
        stack.push(null);
        break;
      case '2':
        stack.push(str[i] === '1');
        i++;
        break;
      case '3':
        var parsedNum = parseNumber(str, i);
        stack.push(parsedNum.num);
        i += parsedNum.length;
        break;
      case '4':
        var parsedStr = '';
        /*eslint no-constant-condition: ["error", { "checkLoops": false }]*/
        while (true) {
          var ch = str[i];
          if (ch === '\u0000') {
            break;
          }
          parsedStr += ch;
          i++;
        }
        // perform the reverse of the order-preserving replacement
        // algorithm (see above)
        parsedStr = parsedStr.replace(/\u0001\u0001/g, '\u0000')
          .replace(/\u0001\u0002/g, '\u0001')
          .replace(/\u0002\u0002/g, '\u0002');
        stack.push(parsedStr);
        break;
      case '5':
        var arrayElement = { element: [], index: stack.length };
        stack.push(arrayElement.element);
        metaStack.push(arrayElement);
        break;
      case '6':
        var objElement = { element: {}, index: stack.length };
        stack.push(objElement.element);
        metaStack.push(objElement);
        break;
      /* istanbul ignore next */
      default:
        throw new Error(
          'bad collationIndex or unexpectedly reached end of input: ' +
            collationIndex);
    }
  }
}

function arrayCollate(a, b) {
  var len = Math.min(a.length, b.length);
  for (var i = 0; i < len; i++) {
    var sort = collate(a[i], b[i]);
    if (sort !== 0) {
      return sort;
    }
  }
  return (a.length === b.length) ? 0 :
    (a.length > b.length) ? 1 : -1;
}
function stringCollate(a, b) {
  // See: https://github.com/daleharvey/pouchdb/issues/40
  // This is incompatible with the CouchDB implementation, but its the
  // best we can do for now
  return (a === b) ? 0 : ((a > b) ? 1 : -1);
}
function objectCollate(a, b) {
  var ak = Object.keys(a), bk = Object.keys(b);
  var len = Math.min(ak.length, bk.length);
  for (var i = 0; i < len; i++) {
    // First sort the keys
    var sort = collate(ak[i], bk[i]);
    if (sort !== 0) {
      return sort;
    }
    // if the keys are equal sort the values
    sort = collate(a[ak[i]], b[bk[i]]);
    if (sort !== 0) {
      return sort;
    }

  }
  return (ak.length === bk.length) ? 0 :
    (ak.length > bk.length) ? 1 : -1;
}
// The collation is defined by erlangs ordered terms
// the atoms null, true, false come first, then numbers, strings,
// arrays, then objects
// null/undefined/NaN/Infinity/-Infinity are all considered null
function collationIndex(x) {
  var id = ['boolean', 'number', 'string', 'object'];
  var idx = id.indexOf(typeof x);
  //false if -1 otherwise true, but fast!!!!1
  if (~idx) {
    if (x === null) {
      return 1;
    }
    if (Array.isArray(x)) {
      return 5;
    }
    return idx < 3 ? (idx + 2) : (idx + 3);
  }
  /* istanbul ignore next */
  if (Array.isArray(x)) {
    return 5;
  }
}

// conversion:
// x yyy zz...zz
// x = 0 for negative, 1 for 0, 2 for positive
// y = exponent (for negative numbers negated) moved so that it's >= 0
// z = mantisse
function numToIndexableString(num) {

  if (num === 0) {
    return '1';
  }

  // convert number to exponential format for easier and
  // more succinct string sorting
  var expFormat = num.toExponential().split(/e\+?/);
  var magnitude = parseInt(expFormat[1], 10);

  var neg = num < 0;

  var result = neg ? '0' : '2';

  // first sort by magnitude
  // it's easier if all magnitudes are positive
  var magForComparison = ((neg ? -magnitude : magnitude) - MIN_MAGNITUDE);
  var magString = padLeft((magForComparison).toString(), '0', MAGNITUDE_DIGITS);

  result += SEP + magString;

  // then sort by the factor
  var factor = Math.abs(parseFloat(expFormat[0])); // [1..10)
  /* istanbul ignore next */
  if (neg) { // for negative reverse ordering
    factor = 10 - factor;
  }

  var factorStr = factor.toFixed(20);

  // strip zeros from the end
  factorStr = factorStr.replace(/\.?0+$/, '');

  result += SEP + factorStr;

  return result;
}

exports.collate = collate;
exports.normalizeKey = normalizeKey;
exports.toIndexableString = toIndexableString;
exports.parseIndexableString = parseIndexableString;

},{}],10:[function(require,module,exports){
'use strict';

Object.defineProperty(exports, '__esModule', { value: true });

function mangle(key) {
  return '$' + key;
}
function unmangle(key) {
  return key.substring(1);
}
function Map$1() {
  this._store = {};
}
Map$1.prototype.get = function (key) {
  var mangled = mangle(key);
  return this._store[mangled];
};
Map$1.prototype.set = function (key, value) {
  var mangled = mangle(key);
  this._store[mangled] = value;
  return true;
};
Map$1.prototype.has = function (key) {
  var mangled = mangle(key);
  return mangled in this._store;
};
Map$1.prototype.delete = function (key) {
  var mangled = mangle(key);
  var res = mangled in this._store;
  delete this._store[mangled];
  return res;
};
Map$1.prototype.forEach = function (cb) {
  var keys = Object.keys(this._store);
  for (var i = 0, len = keys.length; i < len; i++) {
    var key = keys[i];
    var value = this._store[key];
    key = unmangle(key);
    cb(value, key);
  }
};
Object.defineProperty(Map$1.prototype, 'size', {
  get: function () {
    return Object.keys(this._store).length;
  }
});

function Set$1(array) {
  this._store = new Map$1();

  // init with an array
  if (array && Array.isArray(array)) {
    for (var i = 0, len = array.length; i < len; i++) {
      this.add(array[i]);
    }
  }
}
Set$1.prototype.add = function (key) {
  return this._store.set(key, true);
};
Set$1.prototype.has = function (key) {
  return this._store.has(key);
};
Set$1.prototype.forEach = function (cb) {
  this._store.forEach(function (value, key) {
    cb(key);
  });
};
Object.defineProperty(Set$1.prototype, 'size', {
  get: function () {
    return this._store.size;
  }
});

/* global Map,Set,Symbol */
// Based on https://kangax.github.io/compat-table/es6/ we can sniff out
// incomplete Map/Set implementations which would otherwise cause our tests to fail.
// Notably they fail in IE11 and iOS 8.4, which this prevents.
function supportsMapAndSet() {
  if (typeof Symbol === 'undefined' || typeof Map === 'undefined' || typeof Set === 'undefined') {
    return false;
  }
  var prop = Object.getOwnPropertyDescriptor(Map, Symbol.species);
  return prop && 'get' in prop && Map[Symbol.species] === Map;
}

// based on https://github.com/montagejs/collections
/* global Map,Set */

{
  if (supportsMapAndSet()) { // prefer built-in Map/Set
    exports.Set = Set;
    exports.Map = Map;
  } else { // fall back to our polyfill
    exports.Set = Set$1;
    exports.Map = Map$1;
  }
}

},{}],11:[function(require,module,exports){
'use strict';

Object.defineProperty(exports, '__esModule', { value: true });

function _interopDefault (ex) { return (ex && (typeof ex === 'object') && 'default' in ex) ? ex['default'] : ex; }

var inherits = _interopDefault(require('inherits'));

inherits(PouchError, Error);

function PouchError(status, error, reason) {
  Error.call(this, reason);
  this.status = status;
  this.name = error;
  this.message = reason;
  this.error = true;
}

PouchError.prototype.toString = function () {
  return JSON.stringify({
    status: this.status,
    name: this.name,
    message: this.message,
    reason: this.reason
  });
};

var UNAUTHORIZED = new PouchError(401, 'unauthorized', "Name or password is incorrect.");
var MISSING_BULK_DOCS = new PouchError(400, 'bad_request', "Missing JSON list of 'docs'");
var MISSING_DOC = new PouchError(404, 'not_found', 'missing');
var REV_CONFLICT = new PouchError(409, 'conflict', 'Document update conflict');
var INVALID_ID = new PouchError(400, 'bad_request', '_id field must contain a string');
var MISSING_ID = new PouchError(412, 'missing_id', '_id is required for puts');
var RESERVED_ID = new PouchError(400, 'bad_request', 'Only reserved document ids may start with underscore.');
var NOT_OPEN = new PouchError(412, 'precondition_failed', 'Database not open');
var UNKNOWN_ERROR = new PouchError(500, 'unknown_error', 'Database encountered an unknown error');
var BAD_ARG = new PouchError(500, 'badarg', 'Some query argument is invalid');
var INVALID_REQUEST = new PouchError(400, 'invalid_request', 'Request was invalid');
var QUERY_PARSE_ERROR = new PouchError(400, 'query_parse_error', 'Some query parameter is invalid');
var DOC_VALIDATION = new PouchError(500, 'doc_validation', 'Bad special document member');
var BAD_REQUEST = new PouchError(400, 'bad_request', 'Something wrong with the request');
var NOT_AN_OBJECT = new PouchError(400, 'bad_request', 'Document must be a JSON object');
var DB_MISSING = new PouchError(404, 'not_found', 'Database not found');
var IDB_ERROR = new PouchError(500, 'indexed_db_went_bad', 'unknown');
var WSQ_ERROR = new PouchError(500, 'web_sql_went_bad', 'unknown');
var LDB_ERROR = new PouchError(500, 'levelDB_went_went_bad', 'unknown');
var FORBIDDEN = new PouchError(403, 'forbidden', 'Forbidden by design doc validate_doc_update function');
var INVALID_REV = new PouchError(400, 'bad_request', 'Invalid rev format');
var FILE_EXISTS = new PouchError(412, 'file_exists', 'The database could not be created, the file already exists.');
var MISSING_STUB = new PouchError(412, 'missing_stub', 'A pre-existing attachment stub wasn\'t found');
var INVALID_URL = new PouchError(413, 'invalid_url', 'Provided URL is invalid');

function createError(error, reason) {
  function CustomPouchError(reason) {
    // inherit error properties from our parent error manually
    // so as to allow proper JSON parsing.
    /* jshint ignore:start */
    for (var p in error) {
      if (typeof error[p] !== 'function') {
        this[p] = error[p];
      }
    }
    /* jshint ignore:end */
    if (reason !== undefined) {
      this.reason = reason;
    }
  }
  CustomPouchError.prototype = PouchError.prototype;
  return new CustomPouchError(reason);
}

function generateErrorFromResponse(err) {

  if (typeof err !== 'object') {
    var data = err;
    err = UNKNOWN_ERROR;
    err.data = data;
  }

  if ('error' in err && err.error === 'conflict') {
    err.name = 'conflict';
    err.status = 409;
  }

  if (!('name' in err)) {
    err.name = err.error || 'unknown';
  }

  if (!('status' in err)) {
    err.status = 500;
  }

  if (!('message' in err)) {
    err.message = err.message || err.reason;
  }

  return err;
}

exports.UNAUTHORIZED = UNAUTHORIZED;
exports.MISSING_BULK_DOCS = MISSING_BULK_DOCS;
exports.MISSING_DOC = MISSING_DOC;
exports.REV_CONFLICT = REV_CONFLICT;
exports.INVALID_ID = INVALID_ID;
exports.MISSING_ID = MISSING_ID;
exports.RESERVED_ID = RESERVED_ID;
exports.NOT_OPEN = NOT_OPEN;
exports.UNKNOWN_ERROR = UNKNOWN_ERROR;
exports.BAD_ARG = BAD_ARG;
exports.INVALID_REQUEST = INVALID_REQUEST;
exports.QUERY_PARSE_ERROR = QUERY_PARSE_ERROR;
exports.DOC_VALIDATION = DOC_VALIDATION;
exports.BAD_REQUEST = BAD_REQUEST;
exports.NOT_AN_OBJECT = NOT_AN_OBJECT;
exports.DB_MISSING = DB_MISSING;
exports.WSQ_ERROR = WSQ_ERROR;
exports.LDB_ERROR = LDB_ERROR;
exports.FORBIDDEN = FORBIDDEN;
exports.INVALID_REV = INVALID_REV;
exports.FILE_EXISTS = FILE_EXISTS;
exports.MISSING_STUB = MISSING_STUB;
exports.IDB_ERROR = IDB_ERROR;
exports.INVALID_URL = INVALID_URL;
exports.createError = createError;
exports.generateErrorFromResponse = generateErrorFromResponse;

},{"inherits":7}],12:[function(require,module,exports){
'use strict';

function _interopDefault (ex) { return (ex && (typeof ex === 'object') && 'default' in ex) ? ex['default'] : ex; }

var lie = _interopDefault(require('lie'));

/* istanbul ignore next */
var PouchPromise = typeof Promise === 'function' ? Promise : lie;

module.exports = PouchPromise;

},{"lie":8}],13:[function(require,module,exports){
'use strict';

Object.defineProperty(exports, '__esModule', { value: true });

var pouchdbUtils = require('pouchdb-utils');
var pouchdbCollate = require('pouchdb-collate');

// this would just be "return doc[field]", but fields
// can be "deep" due to dot notation
function getFieldFromDoc(doc, parsedField) {
  var value = doc;
  for (var i = 0, len = parsedField.length; i < len; i++) {
    var key = parsedField[i];
    value = value[key];
    if (!value) {
      break;
    }
  }
  return value;
}

function setFieldInDoc(doc, parsedField, value) {
  for (var i = 0, len = parsedField.length; i < len-1; i++) {
    var elem = parsedField[i];
    doc = doc[elem] = {};
  }
  doc[parsedField[len-1]] = value;
}

function compare(left, right) {
  return left < right ? -1 : left > right ? 1 : 0;
}

// Converts a string in dot notation to an array of its components, with backslash escaping
function parseField(fieldName) {
  // fields may be deep (e.g. "foo.bar.baz"), so parse
  var fields = [];
  var current = '';
  for (var i = 0, len = fieldName.length; i < len; i++) {
    var ch = fieldName[i];
    if (ch === '.') {
      if (i > 0 && fieldName[i - 1] === '\\') { // escaped delimiter
        current = current.substring(0, current.length - 1) + '.';
      } else { // not escaped, so delimiter
        fields.push(current);
        current = '';
      }
    } else { // normal character
      current += ch;
    }
  }
  fields.push(current);
  return fields;
}

var combinationFields = ['$or', '$nor', '$not'];
function isCombinationalField(field) {
  return combinationFields.indexOf(field) > -1;
}

function getKey(obj) {
  return Object.keys(obj)[0];
}

function getValue(obj) {
  return obj[getKey(obj)];
}


// flatten an array of selectors joined by an $and operator
function mergeAndedSelectors(selectors) {

  // sort to ensure that e.g. if the user specified
  // $and: [{$gt: 'a'}, {$gt: 'b'}], then it's collapsed into
  // just {$gt: 'b'}
  var res = {};

  selectors.forEach(function (selector) {
    Object.keys(selector).forEach(function (field) {
      var matcher = selector[field];
      if (typeof matcher !== 'object') {
        matcher = {$eq: matcher};
      }

      if (isCombinationalField(field)) {
        if (matcher instanceof Array) {
          res[field] = matcher.map(function (m) {
            return mergeAndedSelectors([m]);
          });
        } else {
          res[field] = mergeAndedSelectors([matcher]);
        }
      } else {
        var fieldMatchers = res[field] = res[field] || {};
        Object.keys(matcher).forEach(function (operator) {
          var value = matcher[operator];

          if (operator === '$gt' || operator === '$gte') {
            return mergeGtGte(operator, value, fieldMatchers);
          } else if (operator === '$lt' || operator === '$lte') {
            return mergeLtLte(operator, value, fieldMatchers);
          } else if (operator === '$ne') {
            return mergeNe(value, fieldMatchers);
          } else if (operator === '$eq') {
            return mergeEq(value, fieldMatchers);
          }
          fieldMatchers[operator] = value;
        });
      }
    });
  });

  return res;
}



// collapse logically equivalent gt/gte values
function mergeGtGte(operator, value, fieldMatchers) {
  if (typeof fieldMatchers.$eq !== 'undefined') {
    return; // do nothing
  }
  if (typeof fieldMatchers.$gte !== 'undefined') {
    if (operator === '$gte') {
      if (value > fieldMatchers.$gte) { // more specificity
        fieldMatchers.$gte = value;
      }
    } else { // operator === '$gt'
      if (value >= fieldMatchers.$gte) { // more specificity
        delete fieldMatchers.$gte;
        fieldMatchers.$gt = value;
      }
    }
  } else if (typeof fieldMatchers.$gt !== 'undefined') {
    if (operator === '$gte') {
      if (value > fieldMatchers.$gt) { // more specificity
        delete fieldMatchers.$gt;
        fieldMatchers.$gte = value;
      }
    } else { // operator === '$gt'
      if (value > fieldMatchers.$gt) { // more specificity
        fieldMatchers.$gt = value;
      }
    }
  } else {
    fieldMatchers[operator] = value;
  }
}

// collapse logically equivalent lt/lte values
function mergeLtLte(operator, value, fieldMatchers) {
  if (typeof fieldMatchers.$eq !== 'undefined') {
    return; // do nothing
  }
  if (typeof fieldMatchers.$lte !== 'undefined') {
    if (operator === '$lte') {
      if (value < fieldMatchers.$lte) { // more specificity
        fieldMatchers.$lte = value;
      }
    } else { // operator === '$gt'
      if (value <= fieldMatchers.$lte) { // more specificity
        delete fieldMatchers.$lte;
        fieldMatchers.$lt = value;
      }
    }
  } else if (typeof fieldMatchers.$lt !== 'undefined') {
    if (operator === '$lte') {
      if (value < fieldMatchers.$lt) { // more specificity
        delete fieldMatchers.$lt;
        fieldMatchers.$lte = value;
      }
    } else { // operator === '$gt'
      if (value < fieldMatchers.$lt) { // more specificity
        fieldMatchers.$lt = value;
      }
    }
  } else {
    fieldMatchers[operator] = value;
  }
}

// combine $ne values into one array
function mergeNe(value, fieldMatchers) {
  if ('$ne' in fieldMatchers) {
    // there are many things this could "not" be
    fieldMatchers.$ne.push(value);
  } else { // doesn't exist yet
    fieldMatchers.$ne = [value];
  }
}

// add $eq into the mix
function mergeEq(value, fieldMatchers) {
  // these all have less specificity than the $eq
  // TODO: check for user errors here
  delete fieldMatchers.$gt;
  delete fieldMatchers.$gte;
  delete fieldMatchers.$lt;
  delete fieldMatchers.$lte;
  delete fieldMatchers.$ne;
  fieldMatchers.$eq = value;
}


//
// normalize the selector
//
function massageSelector(input) {
  var result = pouchdbUtils.clone(input);
  var wasAnded = false;
  if ('$and' in result) {
    result = mergeAndedSelectors(result['$and']);
    wasAnded = true;
  }

  ['$or', '$nor'].forEach(function (orOrNor) {
    if (orOrNor in result) {
      // message each individual selector
      // e.g. {foo: 'bar'} becomes {foo: {$eq: 'bar'}}
      result[orOrNor].forEach(function (subSelector) {
        var fields = Object.keys(subSelector);
        for (var i = 0; i < fields.length; i++) {
          var field = fields[i];
          var matcher = subSelector[field];
          if (typeof matcher !== 'object' || matcher === null) {
            subSelector[field] = {$eq: matcher};
          }
        }
      });
    }
  });

  if ('$not' in result) {
    //This feels a little like forcing, but it will work for now,
    //I would like to come back to this and make the merging of selectors a little more generic
    result['$not'] = mergeAndedSelectors([result['$not']]);
  }

  var fields = Object.keys(result);

  for (var i = 0; i < fields.length; i++) {
    var field = fields[i];
    var matcher = result[field];

    if (typeof matcher !== 'object' || matcher === null) {
      matcher = {$eq: matcher};
    } else if ('$ne' in matcher && !wasAnded) {
      // I put these in an array, since there may be more than one
      // but in the "mergeAnded" operation, I already take care of that
      matcher.$ne = [matcher.$ne];
    }
    result[field] = matcher;
  }

  return result;
}

// create a comparator based on the sort object
function createFieldSorter(sort) {

  function getFieldValuesAsArray(doc) {
    return sort.map(function (sorting) {
      var fieldName = getKey(sorting);
      var parsedField = parseField(fieldName);
      var docFieldValue = getFieldFromDoc(doc, parsedField);
      return docFieldValue;
    });
  }

  return function (aRow, bRow) {
    var aFieldValues = getFieldValuesAsArray(aRow.doc);
    var bFieldValues = getFieldValuesAsArray(bRow.doc);
    var collation = pouchdbCollate.collate(aFieldValues, bFieldValues);
    if (collation !== 0) {
      return collation;
    }
    // this is what mango seems to do
    return compare(aRow.doc._id, bRow.doc._id);
  };
}

function filterInMemoryFields(rows, requestDef, inMemoryFields) {
  rows = rows.filter(function (row) {
    return rowFilter(row.doc, requestDef.selector, inMemoryFields);
  });

  if (requestDef.sort) {
    // in-memory sort
    var fieldSorter = createFieldSorter(requestDef.sort);
    rows = rows.sort(fieldSorter);
    if (typeof requestDef.sort[0] !== 'string' &&
        getValue(requestDef.sort[0]) === 'desc') {
      rows = rows.reverse();
    }
  }

  if ('limit' in requestDef || 'skip' in requestDef) {
    // have to do the limit in-memory
    var skip = requestDef.skip || 0;
    var limit = ('limit' in requestDef ? requestDef.limit : rows.length) + skip;
    rows = rows.slice(skip, limit);
  }
  return rows;
}

function rowFilter(doc, selector, inMemoryFields) {
  return inMemoryFields.every(function (field) {
    if (isDesignDoc(doc)) {
      return false;
    }

    var matcher = selector[field];
    var parsedField = parseField(field);
    var docFieldValue = getFieldFromDoc(doc, parsedField);
    if (isCombinationalField(field)) {
      return matchCominationalSelector(field, matcher, doc);
    }

    return matchSelector(matcher, doc, parsedField, docFieldValue);
  });
}

function isDesignDoc(doc) {
  return /^_design\//.test(doc._id);
}

function matchSelector(matcher, doc, parsedField, docFieldValue) {
  if (!matcher) {
    // no filtering necessary; this field is just needed for sorting
    return true;
  }

  return Object.keys(matcher).every(function (userOperator) {
    var userValue = matcher[userOperator];
    return match(userOperator, doc, userValue, parsedField, docFieldValue);
  });
}

function matchCominationalSelector(field, matcher, doc) {

  if (field === '$or') {
    return matcher.some(function (orMatchers) {
      return rowFilter(doc, orMatchers, Object.keys(orMatchers));
    });
  }

  if (field === '$not') {
    return !rowFilter(doc, matcher, Object.keys(matcher));
  }

  //`$nor`
  return !matcher.find(function (orMatchers) {
    return rowFilter(doc, orMatchers, Object.keys(orMatchers));
  });

}

function match(userOperator, doc, userValue, parsedField, docFieldValue) {
  if (!matchers[userOperator]) {
    throw new Error('unknown operator "' + userOperator +
      '" - should be one of $eq, $lte, $lt, $gt, $gte, $exists, $ne, $in, ' +
      '$nin, $size, $mod, $regex, $elemMatch, $type or $all');
  }
  return matchers[userOperator](doc, userValue, parsedField, docFieldValue);
}

function fieldExists(docFieldValue) {
  return typeof docFieldValue !== 'undefined' && docFieldValue !== null;
}

function fieldIsNotUndefined(docFieldValue) {
  return typeof docFieldValue !== 'undefined';
}

function modField(docFieldValue, userValue) {
  var divisor = userValue[0];
  var mod = userValue[1];
  if (divisor === 0) {
    throw new Error('Bad divisor, cannot divide by zero');
  }

  if (parseInt(divisor, 10) !== divisor ) {
    throw new Error('Divisor is not an integer');
  }

  if (parseInt(mod, 10) !== mod ) {
    throw new Error('Modulus is not an integer');
  }

  if (parseInt(docFieldValue, 10) !== docFieldValue) {
    return false;
  }

  return docFieldValue % divisor === mod;
}

function arrayContainsValue(docFieldValue, userValue) {
  return userValue.some(function (val) {
    if (docFieldValue instanceof Array) {
      return docFieldValue.indexOf(val) > -1;
    }

    return docFieldValue === val;
  });
}

function arrayContainsAllValues(docFieldValue, userValue) {
  return userValue.every(function (val) {
    return docFieldValue.indexOf(val) > -1;
  });
}

function arraySize(docFieldValue, userValue) {
  return docFieldValue.length === userValue;
}

function regexMatch(docFieldValue, userValue) {
  var re = new RegExp(userValue);

  return re.test(docFieldValue);
}

function typeMatch(docFieldValue, userValue) {

  switch (userValue) {
    case 'null':
      return docFieldValue === null;
    case 'boolean':
      return typeof (docFieldValue) === 'boolean';
    case 'number':
      return typeof (docFieldValue) === 'number';
    case 'string':
      return typeof (docFieldValue) === 'string';
    case 'array':
      return docFieldValue instanceof Array;
    case 'object':
      return ({}).toString.call(docFieldValue) === '[object Object]';
  }

  throw new Error(userValue + ' not supported as a type.' +
                  'Please use one of object, string, array, number, boolean or null.');

}

var matchers = {

  '$elemMatch': function (doc, userValue, parsedField, docFieldValue) {
    if (!Array.isArray(docFieldValue)) {
      return false;
    }

    if (docFieldValue.length === 0) {
      return false;
    }

    if (typeof docFieldValue[0] === 'object') {
      return docFieldValue.some(function (val) {
        return rowFilter(val, userValue, Object.keys(userValue));
      });
    }

    return docFieldValue.some(function (val) {
      return matchSelector(userValue, doc, parsedField, val);
    });
  },

  '$eq': function (doc, userValue, parsedField, docFieldValue) {
    return fieldIsNotUndefined(docFieldValue) && pouchdbCollate.collate(docFieldValue, userValue) === 0;
  },

  '$gte': function (doc, userValue, parsedField, docFieldValue) {
    return fieldIsNotUndefined(docFieldValue) && pouchdbCollate.collate(docFieldValue, userValue) >= 0;
  },

  '$gt': function (doc, userValue, parsedField, docFieldValue) {
    return fieldIsNotUndefined(docFieldValue) && pouchdbCollate.collate(docFieldValue, userValue) > 0;
  },

  '$lte': function (doc, userValue, parsedField, docFieldValue) {
    return fieldIsNotUndefined(docFieldValue) && pouchdbCollate.collate(docFieldValue, userValue) <= 0;
  },

  '$lt': function (doc, userValue, parsedField, docFieldValue) {
    return fieldIsNotUndefined(docFieldValue) && pouchdbCollate.collate(docFieldValue, userValue) < 0;
  },

  '$exists': function (doc, userValue, parsedField, docFieldValue) {
    //a field that is null is still considered to exist
    if (userValue) {
      return fieldIsNotUndefined(docFieldValue);
    }

    return !fieldIsNotUndefined(docFieldValue);
  },

  '$mod': function (doc, userValue, parsedField, docFieldValue) {
    return fieldExists(docFieldValue) && modField(docFieldValue, userValue);
  },

  '$ne': function (doc, userValue, parsedField, docFieldValue) {
    return userValue.every(function (neValue) {
      return pouchdbCollate.collate(docFieldValue, neValue) !== 0;
    });
  },
  '$in': function (doc, userValue, parsedField, docFieldValue) {
    return fieldExists(docFieldValue) && arrayContainsValue(docFieldValue, userValue);
  },

  '$nin': function (doc, userValue, parsedField, docFieldValue) {
    return fieldExists(docFieldValue) && !arrayContainsValue(docFieldValue, userValue);
  },

  '$size': function (doc, userValue, parsedField, docFieldValue) {
    return fieldExists(docFieldValue) && arraySize(docFieldValue, userValue);
  },

  '$all': function (doc, userValue, parsedField, docFieldValue) {
    return Array.isArray(docFieldValue) && arrayContainsAllValues(docFieldValue, userValue);
  },

  '$regex': function (doc, userValue, parsedField, docFieldValue) {
    return fieldExists(docFieldValue) && regexMatch(docFieldValue, userValue);
  },

  '$type': function (doc, userValue, parsedField, docFieldValue) {
    return typeMatch(docFieldValue, userValue);
  }
};

// return true if the given doc matches the supplied selector
function matchesSelector(doc, selector) {
  /* istanbul ignore if */
  if (typeof selector !== 'object') {
    // match the CouchDB error message
    throw 'Selector error: expected a JSON object';
  }

  selector = massageSelector(selector);
  var row = {
    'doc': doc
  };

  var rowsMatched = filterInMemoryFields([row], { 'selector': selector }, Object.keys(selector));
  return rowsMatched && rowsMatched.length === 1;
}

exports.massageSelector = massageSelector;
exports.matchesSelector = matchesSelector;
exports.filterInMemoryFields = filterInMemoryFields;
exports.createFieldSorter = createFieldSorter;
exports.rowFilter = rowFilter;
exports.isCombinationalField = isCombinationalField;
exports.getKey = getKey;
exports.getValue = getValue;
exports.getFieldFromDoc = getFieldFromDoc;
exports.setFieldInDoc = setFieldInDoc;
exports.compare = compare;
exports.parseField = parseField;

},{"pouchdb-collate":9,"pouchdb-utils":14}],14:[function(require,module,exports){
'use strict';

Object.defineProperty(exports, '__esModule', { value: true });

function _interopDefault (ex) { return (ex && (typeof ex === 'object') && 'default' in ex) ? ex['default'] : ex; }

var Promise = _interopDefault(require('pouchdb-promise'));
var getArguments = _interopDefault(require('argsarray'));
var pouchdbCollections = require('pouchdb-collections');
var events = require('events');
var inherits = _interopDefault(require('inherits'));
var immediate = _interopDefault(require('immediate'));
var pouchdbErrors = require('pouchdb-errors');

function isBinaryObject(object) {
  return (typeof ArrayBuffer !== 'undefined' && object instanceof ArrayBuffer) ||
    (typeof Blob !== 'undefined' && object instanceof Blob);
}

function cloneArrayBuffer(buff) {
  if (typeof buff.slice === 'function') {
    return buff.slice(0);
  }
  // IE10-11 slice() polyfill
  var target = new ArrayBuffer(buff.byteLength);
  var targetArray = new Uint8Array(target);
  var sourceArray = new Uint8Array(buff);
  targetArray.set(sourceArray);
  return target;
}

function cloneBinaryObject(object) {
  if (object instanceof ArrayBuffer) {
    return cloneArrayBuffer(object);
  }
  var size = object.size;
  var type = object.type;
  // Blob
  if (typeof object.slice === 'function') {
    return object.slice(0, size, type);
  }
  // PhantomJS slice() replacement
  return object.webkitSlice(0, size, type);
}

// most of this is borrowed from lodash.isPlainObject:
// https://github.com/fis-components/lodash.isplainobject/
// blob/29c358140a74f252aeb08c9eb28bef86f2217d4a/index.js

var funcToString = Function.prototype.toString;
var objectCtorString = funcToString.call(Object);

function isPlainObject(value) {
  var proto = Object.getPrototypeOf(value);
  /* istanbul ignore if */
  if (proto === null) { // not sure when this happens, but I guess it can
    return true;
  }
  var Ctor = proto.constructor;
  return (typeof Ctor == 'function' &&
    Ctor instanceof Ctor && funcToString.call(Ctor) == objectCtorString);
}

function clone(object) {
  var newObject;
  var i;
  var len;

  if (!object || typeof object !== 'object') {
    return object;
  }

  if (Array.isArray(object)) {
    newObject = [];
    for (i = 0, len = object.length; i < len; i++) {
      newObject[i] = clone(object[i]);
    }
    return newObject;
  }

  // special case: to avoid inconsistencies between IndexedDB
  // and other backends, we automatically stringify Dates
  if (object instanceof Date) {
    return object.toISOString();
  }

  if (isBinaryObject(object)) {
    return cloneBinaryObject(object);
  }

  if (!isPlainObject(object)) {
    return object; // don't clone objects like Workers
  }

  newObject = {};
  for (i in object) {
    /* istanbul ignore else */
    if (Object.prototype.hasOwnProperty.call(object, i)) {
      var value = clone(object[i]);
      if (typeof value !== 'undefined') {
        newObject[i] = value;
      }
    }
  }
  return newObject;
}

function once(fun) {
  var called = false;
  return getArguments(function (args) {
    /* istanbul ignore if */
    if (called) {
      // this is a smoke test and should never actually happen
      throw new Error('once called more than once');
    } else {
      called = true;
      fun.apply(this, args);
    }
  });
}

function toPromise(func) {
  //create the function we will be returning
  return getArguments(function (args) {
    // Clone arguments
    args = clone(args);
    var self = this;
    // if the last argument is a function, assume its a callback
    var usedCB = (typeof args[args.length - 1] === 'function') ? args.pop() : false;
    var promise = new Promise(function (fulfill, reject) {
      var resp;
      try {
        var callback = once(function (err, mesg) {
          if (err) {
            reject(err);
          } else {
            fulfill(mesg);
          }
        });
        // create a callback for this invocation
        // apply the function in the orig context
        args.push(callback);
        resp = func.apply(self, args);
        if (resp && typeof resp.then === 'function') {
          fulfill(resp);
        }
      } catch (e) {
        reject(e);
      }
    });
    // if there is a callback, call it back
    if (usedCB) {
      promise.then(function (result) {
        usedCB(null, result);
      }, usedCB);
    }
    return promise;
  });
}

function logApiCall(self, name, args) {
  /* istanbul ignore if */
  if (self.constructor.listeners('debug').length) {
    var logArgs = ['api', self.name, name];
    for (var i = 0; i < args.length - 1; i++) {
      logArgs.push(args[i]);
    }
    self.constructor.emit('debug', logArgs);

    // override the callback itself to log the response
    var origCallback = args[args.length - 1];
    args[args.length - 1] = function (err, res) {
      var responseArgs = ['api', self.name, name];
      responseArgs = responseArgs.concat(
        err ? ['error', err] : ['success', res]
      );
      self.constructor.emit('debug', responseArgs);
      origCallback(err, res);
    };
  }
}

function adapterFun(name, callback) {
  return toPromise(getArguments(function (args) {
    if (this._closed) {
      return Promise.reject(new Error('database is closed'));
    }
    if (this._destroyed) {
      return Promise.reject(new Error('database is destroyed'));
    }
    var self = this;
    logApiCall(self, name, args);
    if (!this.taskqueue.isReady) {
      return new Promise(function (fulfill, reject) {
        self.taskqueue.addTask(function (failed) {
          if (failed) {
            reject(failed);
          } else {
            fulfill(self[name].apply(self, args));
          }
        });
      });
    }
    return callback.apply(this, args);
  }));
}

// like underscore/lodash _.pick()
function pick(obj, arr) {
  var res = {};
  for (var i = 0, len = arr.length; i < len; i++) {
    var prop = arr[i];
    if (prop in obj) {
      res[prop] = obj[prop];
    }
  }
  return res;
}

// Most browsers throttle concurrent requests at 6, so it's silly
// to shim _bulk_get by trying to launch potentially hundreds of requests
// and then letting the majority time out. We can handle this ourselves.
var MAX_NUM_CONCURRENT_REQUESTS = 6;

function identityFunction(x) {
  return x;
}

function formatResultForOpenRevsGet(result) {
  return [{
    ok: result
  }];
}

// shim for P/CouchDB adapters that don't directly implement _bulk_get
function bulkGet(db, opts, callback) {
  var requests = opts.docs;

  // consolidate into one request per doc if possible
  var requestsById = new pouchdbCollections.Map();
  requests.forEach(function (request) {
    if (requestsById.has(request.id)) {
      requestsById.get(request.id).push(request);
    } else {
      requestsById.set(request.id, [request]);
    }
  });

  var numDocs = requestsById.size;
  var numDone = 0;
  var perDocResults = new Array(numDocs);

  function collapseResultsAndFinish() {
    var results = [];
    perDocResults.forEach(function (res) {
      res.docs.forEach(function (info) {
        results.push({
          id: res.id,
          docs: [info]
        });
      });
    });
    callback(null, {results: results});
  }

  function checkDone() {
    if (++numDone === numDocs) {
      collapseResultsAndFinish();
    }
  }

  function gotResult(docIndex, id, docs) {
    perDocResults[docIndex] = {id: id, docs: docs};
    checkDone();
  }

  var allRequests = [];
  requestsById.forEach(function (value, key) {
    allRequests.push(key);
  });

  var i = 0;

  function nextBatch() {

    if (i >= allRequests.length) {
      return;
    }

    var upTo = Math.min(i + MAX_NUM_CONCURRENT_REQUESTS, allRequests.length);
    var batch = allRequests.slice(i, upTo);
    processBatch(batch, i);
    i += batch.length;
  }

  function processBatch(batch, offset) {
    batch.forEach(function (docId, j) {
      var docIdx = offset + j;
      var docRequests = requestsById.get(docId);

      // just use the first request as the "template"
      // TODO: The _bulk_get API allows for more subtle use cases than this,
      // but for now it is unlikely that there will be a mix of different
      // "atts_since" or "attachments" in the same request, since it's just
      // replicate.js that is using this for the moment.
      // Also, atts_since is aspirational, since we don't support it yet.
      var docOpts = pick(docRequests[0], ['atts_since', 'attachments']);
      docOpts.open_revs = docRequests.map(function (request) {
        // rev is optional, open_revs disallowed
        return request.rev;
      });

      // remove falsey / undefined revisions
      docOpts.open_revs = docOpts.open_revs.filter(identityFunction);

      var formatResult = identityFunction;

      if (docOpts.open_revs.length === 0) {
        delete docOpts.open_revs;

        // when fetching only the "winning" leaf,
        // transform the result so it looks like an open_revs
        // request
        formatResult = formatResultForOpenRevsGet;
      }

      // globally-supplied options
      ['revs', 'attachments', 'binary', 'ajax', 'latest'].forEach(function (param) {
        if (param in opts) {
          docOpts[param] = opts[param];
        }
      });
      db.get(docId, docOpts, function (err, res) {
        var result;
        /* istanbul ignore if */
        if (err) {
          result = [{error: err}];
        } else {
          result = formatResult(res);
        }
        gotResult(docIdx, docId, result);
        nextBatch();
      });
    });
  }

  nextBatch();

}

function isChromeApp() {
  return (typeof chrome !== "undefined" &&
    typeof chrome.storage !== "undefined" &&
    typeof chrome.storage.local !== "undefined");
}

var hasLocal;

if (isChromeApp()) {
  hasLocal = false;
} else {
  try {
    localStorage.setItem('_pouch_check_localstorage', 1);
    hasLocal = !!localStorage.getItem('_pouch_check_localstorage');
  } catch (e) {
    hasLocal = false;
  }
}

function hasLocalStorage() {
  return hasLocal;
}

// Custom nextTick() shim for browsers. In node, this will just be process.nextTick(). We
// avoid using process.nextTick() directly because the polyfill is very large and we don't
// need all of it (see: https://github.com/defunctzombie/node-process).
// "immediate" 3.0.8 is used by lie, and it's a smaller version of the latest "immediate"
// package, so it's the one we use.
// When we use nextTick() in our codebase, we only care about not releasing Zalgo
// (see: http://blog.izs.me/post/59142742143/designing-apis-for-asynchrony).
// Microtask vs macrotask doesn't matter to us. So we're free to use the fastest
// (least latency) option, which is "immediate" due to use of microtasks.
// All of our nextTicks are isolated to this one function so we can easily swap out one
// implementation for another.

inherits(Changes, events.EventEmitter);

/* istanbul ignore next */
function attachBrowserEvents(self) {
  if (isChromeApp()) {
    chrome.storage.onChanged.addListener(function (e) {
      // make sure it's event addressed to us
      if (e.db_name != null) {
        //object only has oldValue, newValue members
        self.emit(e.dbName.newValue);
      }
    });
  } else if (hasLocalStorage()) {
    if (typeof addEventListener !== 'undefined') {
      addEventListener("storage", function (e) {
        self.emit(e.key);
      });
    } else { // old IE
      window.attachEvent("storage", function (e) {
        self.emit(e.key);
      });
    }
  }
}

function Changes() {
  events.EventEmitter.call(this);
  this._listeners = {};

  attachBrowserEvents(this);
}
Changes.prototype.addListener = function (dbName, id, db, opts) {
  /* istanbul ignore if */
  if (this._listeners[id]) {
    return;
  }
  var self = this;
  var inprogress = false;
  function eventFunction() {
    /* istanbul ignore if */
    if (!self._listeners[id]) {
      return;
    }
    if (inprogress) {
      inprogress = 'waiting';
      return;
    }
    inprogress = true;
    var changesOpts = pick(opts, [
      'style', 'include_docs', 'attachments', 'conflicts', 'filter',
      'doc_ids', 'view', 'since', 'query_params', 'binary'
    ]);

    /* istanbul ignore next */
    function onError() {
      inprogress = false;
    }

    db.changes(changesOpts).on('change', function (c) {
      if (c.seq > opts.since && !opts.cancelled) {
        opts.since = c.seq;
        opts.onChange(c);
      }
    }).on('complete', function () {
      if (inprogress === 'waiting') {
        immediate(eventFunction);
      }
      inprogress = false;
    }).on('error', onError);
  }
  this._listeners[id] = eventFunction;
  this.on(dbName, eventFunction);
};

Changes.prototype.removeListener = function (dbName, id) {
  /* istanbul ignore if */
  if (!(id in this._listeners)) {
    return;
  }
  events.EventEmitter.prototype.removeListener.call(this, dbName,
    this._listeners[id]);
  delete this._listeners[id];
};


/* istanbul ignore next */
Changes.prototype.notifyLocalWindows = function (dbName) {
  //do a useless change on a storage thing
  //in order to get other windows's listeners to activate
  if (isChromeApp()) {
    chrome.storage.local.set({dbName: dbName});
  } else if (hasLocalStorage()) {
    localStorage[dbName] = (localStorage[dbName] === "a") ? "b" : "a";
  }
};

Changes.prototype.notify = function (dbName) {
  this.emit(dbName);
  this.notifyLocalWindows(dbName);
};

function guardedConsole(method) {
  /* istanbul ignore else */
  if (console !== 'undefined' && method in console) {
    var args = Array.prototype.slice.call(arguments, 1);
    console[method].apply(console, args);
  }
}

function randomNumber(min, max) {
  var maxTimeout = 600000; // Hard-coded default of 10 minutes
  min = parseInt(min, 10) || 0;
  max = parseInt(max, 10);
  if (max !== max || max <= min) {
    max = (min || 1) << 1; //doubling
  } else {
    max = max + 1;
  }
  // In order to not exceed maxTimeout, pick a random value between half of maxTimeout and maxTimeout
  if (max > maxTimeout) {
    min = maxTimeout >> 1; // divide by two
    max = maxTimeout;
  }
  var ratio = Math.random();
  var range = max - min;

  return ~~(range * ratio + min); // ~~ coerces to an int, but fast.
}

function defaultBackOff(min) {
  var max = 0;
  if (!min) {
    max = 2000;
  }
  return randomNumber(min, max);
}

// designed to give info to browser users, who are disturbed
// when they see http errors in the console
function explainError(status, str) {
  guardedConsole('info', 'The above ' + status + ' is totally normal. ' + str);
}

var assign;
{
  if (typeof Object.assign === 'function') {
    assign = Object.assign;
  } else {
    // lite Object.assign polyfill based on
    // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/assign
    assign = function (target) {
      var to = Object(target);

      for (var index = 1; index < arguments.length; index++) {
        var nextSource = arguments[index];

        if (nextSource != null) { // Skip over if undefined or null
          for (var nextKey in nextSource) {
            // Avoid bugs when hasOwnProperty is shadowed
            if (Object.prototype.hasOwnProperty.call(nextSource, nextKey)) {
              to[nextKey] = nextSource[nextKey];
            }
          }
        }
      }
      return to;
    };
  }
}

var assign$1 = assign;

function tryFilter(filter, doc, req) {
  try {
    return !filter(doc, req);
  } catch (err) {
    var msg = 'Filter function threw: ' + err.toString();
    return pouchdbErrors.createError(pouchdbErrors.BAD_REQUEST, msg);
  }
}

function filterChange(opts) {
  var req = {};
  var hasFilter = opts.filter && typeof opts.filter === 'function';
  req.query = opts.query_params;

  return function filter(change) {
    if (!change.doc) {
      // CSG sends events on the changes feed that don't have documents,
      // this hack makes a whole lot of existing code robust.
      change.doc = {};
    }

    var filterReturn = hasFilter && tryFilter(opts.filter, change.doc, req);

    if (typeof filterReturn === 'object') {
      return filterReturn;
    }

    if (filterReturn) {
      return false;
    }

    if (!opts.include_docs) {
      delete change.doc;
    } else if (!opts.attachments) {
      for (var att in change.doc._attachments) {
        /* istanbul ignore else */
        if (change.doc._attachments.hasOwnProperty(att)) {
          change.doc._attachments[att].stub = true;
        }
      }
    }
    return true;
  };
}

function flatten(arrs) {
  var res = [];
  for (var i = 0, len = arrs.length; i < len; i++) {
    res = res.concat(arrs[i]);
  }
  return res;
}

// shim for Function.prototype.name,
// for browsers that don't support it like IE

/* istanbul ignore next */
function f() {}

var hasName = f.name;
var res;

// We dont run coverage in IE
/* istanbul ignore else */
if (hasName) {
  res = function (fun) {
    return fun.name;
  };
} else {
  res = function (fun) {
    return fun.toString().match(/^\s*function\s*(\S*)\s*\(/)[1];
  };
}

var res$1 = res;

// Determine id an ID is valid
//   - invalid IDs begin with an underescore that does not begin '_design' or
//     '_local'
//   - any other string value is a valid id
// Returns the specific error object for each case
function invalidIdError(id) {
  var err;
  if (!id) {
    err = pouchdbErrors.createError(pouchdbErrors.MISSING_ID);
  } else if (typeof id !== 'string') {
    err = pouchdbErrors.createError(pouchdbErrors.INVALID_ID);
  } else if (/^_/.test(id) && !(/^_(design|local)/).test(id)) {
    err = pouchdbErrors.createError(pouchdbErrors.RESERVED_ID);
  }
  if (err) {
    throw err;
  }
}

function isCordova() {
  return (typeof cordova !== "undefined" ||
  typeof PhoneGap !== "undefined" ||
  typeof phonegap !== "undefined");
}

// Checks if a PouchDB object is "remote" or not. This is
// designed to opt-in to certain optimizations, such as
// avoiding checks for "dependentDbs" and other things that
// we know only apply to local databases. In general, "remote"
// should be true for the http adapter, and for third-party
// adapters with similar expensive boundaries to cross for
// every API call, such as socket-pouch and worker-pouch.
// Previously, this was handled via db.type() === 'http'
// which is now deprecated.

function isRemote(db) {
  if (typeof db._remote === 'boolean') {
    return db._remote;
  }
  /* istanbul ignore next */
  if (typeof db.type === 'function') {
    guardedConsole('warn',
      'db.type() is deprecated and will be removed in ' +
      'a future version of PouchDB');
    return db.type() === 'http';
  }
  /* istanbul ignore next */
  return false;
}

function listenerCount(ee, type) {
  return 'listenerCount' in ee ? ee.listenerCount(type) :
                                 events.EventEmitter.listenerCount(ee, type);
}

function parseDesignDocFunctionName(s) {
  if (!s) {
    return null;
  }
  var parts = s.split('/');
  if (parts.length === 2) {
    return parts;
  }
  if (parts.length === 1) {
    return [s, s];
  }
  return null;
}

function normalizeDesignDocFunctionName(s) {
  var normalized = parseDesignDocFunctionName(s);
  return normalized ? normalized.join('/') : null;
}

// originally parseUri 1.2.2, now patched by us
// (c) Steven Levithan <stevenlevithan.com>
// MIT License
var keys = ["source", "protocol", "authority", "userInfo", "user", "password",
    "host", "port", "relative", "path", "directory", "file", "query", "anchor"];
var qName ="queryKey";
var qParser = /(?:^|&)([^&=]*)=?([^&]*)/g;

// use the "loose" parser
/* jshint maxlen: false */
var parser = /^(?:(?![^:@]+:[^:@\/]*@)([^:\/?#.]+):)?(?:\/\/)?((?:(([^:@]*)(?::([^:@]*))?)?@)?([^:\/?#]*)(?::(\d*))?)(((\/(?:[^?#](?![^?#\/]*\.[^?#\/.]+(?:[?#]|$)))*\/?)?([^?#\/]*))(?:\?([^#]*))?(?:#(.*))?)/;

function parseUri(str) {
  var m = parser.exec(str);
  var uri = {};
  var i = 14;

  while (i--) {
    var key = keys[i];
    var value = m[i] || "";
    var encoded = ['user', 'password'].indexOf(key) !== -1;
    uri[key] = encoded ? decodeURIComponent(value) : value;
  }

  uri[qName] = {};
  uri[keys[12]].replace(qParser, function ($0, $1, $2) {
    if ($1) {
      uri[qName][$1] = $2;
    }
  });

  return uri;
}

// Based on https://github.com/alexdavid/scope-eval v0.0.3
// (source: https://unpkg.com/scope-eval@0.0.3/scope_eval.js)
// This is basically just a wrapper around new Function()

function scopeEval(source, scope) {
  var keys = [];
  var values = [];
  for (var key in scope) {
    if (scope.hasOwnProperty(key)) {
      keys.push(key);
      values.push(scope[key]);
    }
  }
  keys.push(source);
  return Function.apply(null, keys).apply(null, values);
}

// this is essentially the "update sugar" function from daleharvey/pouchdb#1388
// the diffFun tells us what delta to apply to the doc.  it either returns
// the doc, or false if it doesn't need to do an update after all
function upsert(db, docId, diffFun) {
  return new Promise(function (fulfill, reject) {
    db.get(docId, function (err, doc) {
      if (err) {
        /* istanbul ignore next */
        if (err.status !== 404) {
          return reject(err);
        }
        doc = {};
      }

      // the user might change the _rev, so save it for posterity
      var docRev = doc._rev;
      var newDoc = diffFun(doc);

      if (!newDoc) {
        // if the diffFun returns falsy, we short-circuit as
        // an optimization
        return fulfill({updated: false, rev: docRev});
      }

      // users aren't allowed to modify these values,
      // so reset them here
      newDoc._id = docId;
      newDoc._rev = docRev;
      fulfill(tryAndPut(db, newDoc, diffFun));
    });
  });
}

function tryAndPut(db, doc, diffFun) {
  return db.put(doc).then(function (res) {
    return {
      updated: true,
      rev: res.rev
    };
  }, function (err) {
    /* istanbul ignore next */
    if (err.status !== 409) {
      throw err;
    }
    return upsert(db, doc._id, diffFun);
  });
}

// BEGIN Math.uuid.js

/*!
Math.uuid.js (v1.4)
http://www.broofa.com
mailto:robert@broofa.com

Copyright (c) 2010 Robert Kieffer
Dual licensed under the MIT and GPL licenses.
*/

/*
 * Generate a random uuid.
 *
 * USAGE: Math.uuid(length, radix)
 *   length - the desired number of characters
 *   radix  - the number of allowable values for each character.
 *
 * EXAMPLES:
 *   // No arguments  - returns RFC4122, version 4 ID
 *   >>> Math.uuid()
 *   "92329D39-6F5C-4520-ABFC-AAB64544E172"
 *
 *   // One argument - returns ID of the specified length
 *   >>> Math.uuid(15)     // 15 character ID (default base=62)
 *   "VcydxgltxrVZSTV"
 *
 *   // Two arguments - returns ID of the specified length, and radix. 
 *   // (Radix must be <= 62)
 *   >>> Math.uuid(8, 2)  // 8 character ID (base=2)
 *   "01001010"
 *   >>> Math.uuid(8, 10) // 8 character ID (base=10)
 *   "47473046"
 *   >>> Math.uuid(8, 16) // 8 character ID (base=16)
 *   "098F4D35"
 */
var chars = (
  '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ' +
  'abcdefghijklmnopqrstuvwxyz'
).split('');
function getValue(radix) {
  return 0 | Math.random() * radix;
}
function uuid(len, radix) {
  radix = radix || chars.length;
  var out = '';
  var i = -1;

  if (len) {
    // Compact form
    while (++i < len) {
      out += chars[getValue(radix)];
    }
    return out;
  }
    // rfc4122, version 4 form
    // Fill in random data.  At i==19 set the high bits of clock sequence as
    // per rfc4122, sec. 4.1.5
  while (++i < 36) {
    switch (i) {
      case 8:
      case 13:
      case 18:
      case 23:
        out += '-';
        break;
      case 19:
        out += chars[(getValue(16) & 0x3) | 0x8];
        break;
      default:
        out += chars[getValue(16)];
    }
  }

  return out;
}

exports.adapterFun = adapterFun;
exports.bulkGetShim = bulkGet;
exports.changesHandler = Changes;
exports.clone = clone;
exports.defaultBackOff = defaultBackOff;
exports.explainError = explainError;
exports.assign = assign$1;
exports.filterChange = filterChange;
exports.flatten = flatten;
exports.functionName = res$1;
exports.guardedConsole = guardedConsole;
exports.hasLocalStorage = hasLocalStorage;
exports.invalidIdError = invalidIdError;
exports.isChromeApp = isChromeApp;
exports.isCordova = isCordova;
exports.isRemote = isRemote;
exports.listenerCount = listenerCount;
exports.nextTick = immediate;
exports.normalizeDdocFunctionName = normalizeDesignDocFunctionName;
exports.once = once;
exports.parseDdocFunctionName = parseDesignDocFunctionName;
exports.parseUri = parseUri;
exports.pick = pick;
exports.scopeEval = scopeEval;
exports.toPromise = toPromise;
exports.upsert = upsert;
exports.uuid = uuid;

},{"argsarray":4,"events":5,"immediate":6,"inherits":7,"pouchdb-collections":10,"pouchdb-errors":11,"pouchdb-promise":12}]},{},[2]);