events: Use EventEmitter from old version of Node

This was copied from a _very_ early version of node.  The problem is that,
for reasons not yet investigated, Node v12's EventEmitter (at least when
extended by easejs) is causing data to be shared across instances.

This kicks the can down the road a little bit.  The goal is to eventually
get rid of EventEmitter entirely.

Here's the script used to do the conversion in this commit:

git grep -l "require( 'events' )" -- src \
  | while read f; do
      path=$( sed 's|src/||;s|[^/]\+|..|g' <<< "$(dirname "$f")" )
      sed -i "s|require( 'events' )|require( '$path/events' )|" "$f"
    done

src/bucket/QuoteDataBucket.js

@@ -21,7 +21,7 @@
 
 var Class        = require( 'easejs' ).Class,
     Bucket       = require( './Bucket' ),
-    EventEmitter = require( 'events' ).EventEmitter;
+    EventEmitter = require( '../events' ).EventEmitter;
 
 /**
  * General key/value store for document

src/bucket/StagingBucket.js

@@ -24,7 +24,7 @@
 
 const { Class }    = require( 'easejs' );
 const Bucket       = require( './Bucket' );
-const EventEmitter = require( 'events' ).EventEmitter;
+const EventEmitter = require( '../events' ).EventEmitter;
 
 
 /**

src/client/Client.js

@@ -20,7 +20,7 @@
  */
 
 const Class                 = require( 'easejs' ).Class;
-const EventEmitter          = require( 'events' ).EventEmitter;
+const EventEmitter          = require( '../events' ).EventEmitter;
 const DomFieldNotFoundError = require( '../ui/field/DomFieldNotFoundError' );
 const UnknownEventError     = require( './event/UnknownEventError' );
 const system                = require( '../system/client' );

src/client/debug/BucketClientDebugTab.js

@@ -20,7 +20,7 @@
  */
 
 var Class          = require( 'easejs' ).Class,
-    EventEmitter   = require( 'events' ).EventEmitter,
+    EventEmitter   = require( '../../events' ).EventEmitter,
     ClientDebugTab = require( './ClientDebugTab' );
 
 

src/client/debug/ClassifyClientDebugTab.js

@@ -20,7 +20,7 @@
  */
 
 var Class          = require( 'easejs' ).Class,
-    EventEmitter   = require( 'events' ).EventEmitter,
+    EventEmitter   = require( '../../events' ).EventEmitter,
     ClientDebugTab = require( './ClientDebugTab' );
 
 

src/client/debug/ClientDebugDialog.js

@@ -20,7 +20,7 @@
  */
 
 var Class          = require( 'easejs' ).Class,
-    EventEmitter   = require( 'events' ).EventEmitter,
+    EventEmitter   = require( '../../events' ).EventEmitter,
     Client         = require( '../Client' ),
     ClientDebugTab = require( './ClientDebugTab' );
 

src/client/nav/Nav.js

@@ -20,7 +20,7 @@
  */
 
 var Class        = require( 'easejs' ).Class,
-    EventEmitter = require( 'events' ).EventEmitter;
+    EventEmitter = require( '../../events' ).EventEmitter;
 
 
 /**

src/client/proxy/HttpDataProxy.js

@@ -22,7 +22,7 @@
  */
 
 var AbstractClass = require( 'easejs' ).AbstractClass,
-    EventEmitter  = require( 'events' ).EventEmitter;
+    EventEmitter  = require( '../../events' ).EventEmitter;
 
 
 /**

src/client/quote/ClientQuote.js

@@ -21,7 +21,7 @@
 
 var Class        = require( 'easejs' ).Class,
     Quote        = require( '../../quote/Quote' ),
-    EventEmitter = require( 'events' ).EventEmitter;
+    EventEmitter = require( '../../events' ).EventEmitter;
 
 
 /**

src/dapi/DataApiManager.js

@@ -20,7 +20,7 @@
  */
 
 const { Class }        = require( 'easejs' );
-const { EventEmitter } = require( 'events' );
+const { EventEmitter } = require( '../events' );
 const MissingDataError = require( './MissingDataError' );
 
 

src/dapi/QuoteDataApi.js

@@ -25,7 +25,7 @@
 
 const { Class }    = require( 'easejs' );
 const DataApi      = require( './DataApi' );
-const EventEmitter = require( 'events' ).EventEmitter;
+const EventEmitter = require( '../events' ).EventEmitter;
 
 
 /**

src/dapi/RestrictedDataApi.js

@@ -22,7 +22,7 @@
 
 var Class        = require( 'easejs' ).Class,
     DataApi      = require( './DataApi' ),
-    EventEmitter = require( 'events' ).EventEmitter;
+    EventEmitter = require( '../events' ).EventEmitter;
 
 
 /**

src/dapi/StaticAdditionDataApi.js

@@ -22,7 +22,7 @@
 var Class   = require( 'easejs' ).Class,
     DataApi = require( './DataApi' ),
 
-    EventEmitter = require( 'events' ).EventEmitter;
+    EventEmitter = require( '../events' ).EventEmitter;
 
 
 /**

src/events.js

@@ -0,0 +1,132 @@
+/**
+ * Handles events
+ *
+ * This module was taken from a very old verison of node.js. It has been
+ * modified slightly to ensure it works properly outside of the V8 engine.
+ *
+ * Copyright 2009, 2010 Ryan Lienhart Dahl. All rights reserved.  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.
+ */
+
+
+var EventEmitter = exports.EventEmitter = function() {};
+
+EventEmitter.prototype.emit = function(type) {
+  // If there is no 'error' event listener then throw.
+  if (type === 'error') {
+    if (!this._events || !this._events.error ||
+        !this._events.error.length)
+    {
+      if (arguments[1] instanceof Error) {
+        throw arguments[1]; // Unhandled 'error' event
+      } else {
+        throw new Error("Uncaught, unspecified 'error' event.");
+      }
+      return false;
+    }
+  }
+
+  if (!this._events) return false;
+  var handler = this._events[type];
+  if (!handler) return false;
+
+  var args = Array.prototype.slice.call(arguments, 1);
+
+  var listeners = handler.slice();
+  for (var i = 0, l = listeners.length; i < l; i++) {
+    listeners[i].apply(this, args);
+  }
+  return true;
+};
+
+// EventEmitter is defined in src/node_events.cc
+// EventEmitter.prototype.emit() is also defined there.
+EventEmitter.prototype.addListener = function(type, listener) {
+  if ('function' !== typeof listener) {
+    throw new Error('addListener only takes instances of Function');
+  }
+
+  if (!this._events) this._events = {};
+
+  // To avoid recursion in the case that type == "newListeners"! Before
+  // adding it to the listeners, first emit "newListeners".
+  this.emit('newListener', type, listener);
+
+  if (!this._events[type]) {
+    this._events[type] = [];
+  }
+
+  this._events[type].push(listener);
+  return this;
+};
+
+EventEmitter.prototype.on = EventEmitter.prototype.addListener;
+
+EventEmitter.prototype.once = function(type, listener) {
+  var self = this;
+
+  // keep this separate; don't inline (doesn't work in IE)
+  function g() {
+    self.removeListener(type, g);
+    listener.apply(this, arguments);
+  }
+
+  self.on(type, g);
+
+  return this;
+};
+
+EventEmitter.prototype.removeListener = function(type, listener) {
+  if ('function' !== typeof listener) {
+    throw new Error('removeListener only takes instances of Function');
+  }
+
+  // does not use listeners(), so no side effect of creating _events[type]
+  if (!this._events || !this._events[type]) return this;
+
+  var list = this._events[type];
+
+  var position = -1;
+  for (var i = 0, length = list.length; i < length; i++) {
+    if (list[i] === listener ||
+        (list[i].listener && list[i].listener === listener))
+    {
+      position = i;
+      break;
+    }
+  }
+  if (position < 0) return this;
+  list.splice(position, 1);
+  if (list.length == 0)
+    delete this._events[type];
+
+  return this;
+};
+
+EventEmitter.prototype.removeAllListeners = function(type) {
+  // does not use listeners(), so no side effect of creating _events[type]
+  if (type && this._events && this._events[type]) this._events[type] = null;
+  return this;
+};
+
+EventEmitter.prototype.listeners = function(type) {
+  if (!this._events) this._events = {};
+  if (!this._events[type]) this._events[type] = [];
+  return this._events[type];
+};

src/program/Program.js

@@ -22,7 +22,7 @@
  */
 
 var AbstractClass = require( 'easejs' ).AbstractClass
-    EventEmitter  = require( 'events' ).EventEmitter,
+    EventEmitter  = require( '../events' ).EventEmitter,
 
     // XXX coupling
     Failure       = require( '../validate/Failure' ),

src/quote/BaseQuote.js

@@ -24,7 +24,7 @@
 var Class        = require( 'easejs' ).Class,
     Quote        = require( './Quote' ),
     Program      = require( '../program/Program' ).Program,
-    EventEmitter = require( 'events' ).EventEmitter;
+    EventEmitter = require( '../events' ).EventEmitter;
 
 /**
  * Creates a new quote

src/server/Server.js

@@ -23,7 +23,7 @@
  */
 
 const { Class }        = require( 'easejs' );
-const { EventEmitter } = require( 'events' );
+const { EventEmitter } = require( '../events' );
 
 const fs   = require( 'fs' );
 const util = require( 'util' );

src/server/cache/ResilientMemcache.js

@@ -20,7 +20,7 @@
  */
 
 var Class        = require( 'easejs' ).Class,
-    EventEmitter = require( 'events' ).EventEmitter;
+    EventEmitter = require( '../../events' ).EventEmitter;
 
 
 /**

src/server/db/MongoServerDao.js

@@ -20,7 +20,7 @@
  */
 
 var Class        = require( 'easejs' ).Class,
-    EventEmitter = require( 'events' ).EventEmitter,
+    EventEmitter = require( '../../events' ).EventEmitter,
     ServerDao    = require( './ServerDao' ).ServerDao;
 
 

src/server/encsvc/QuoteDataBucketCipher.js

@@ -20,7 +20,7 @@
  */
 
 var Class        = require( 'easejs' ).Class,
-    EventEmitter = require( 'events' ).EventEmitter;
+    EventEmitter = require( '../../events' ).EventEmitter;
 
 
 /**

src/server/rater/DslRater.js

@@ -20,7 +20,7 @@
  */
 
 var Class        = require( 'easejs' ).Class,
-    EventEmitter = require( 'events' ).EventEmitter,
+    EventEmitter = require( '../../events' ).EventEmitter,
 
     DslRaterContext = require( './DslRaterContext' );
 

src/server/rater/DslRaterContext.js

@@ -20,7 +20,7 @@
  */
 
 var Class        = require( 'easejs' ).Class,
-    EventEmitter = require( 'events' ).EventEmitter,
+    EventEmitter = require( '../../events' ).EventEmitter,
     Quote        = require( '../../quote/Quote' );
 
 

src/server/request/UserRequest.js

@@ -28,7 +28,7 @@ var Class = require( 'easejs' ).Class;
  * This class doesn't really add any new functionality. It just makes working
  * with requests and responses a bit easier.
  */
-module.exports = Class.extend( require( 'events' ).EventEmitter,
+module.exports = Class.extend( require( '../../events' ).EventEmitter,
 {
     /**
      * Request timeout in seconds

src/server/request/UserSession.js

@@ -29,7 +29,7 @@ var php   = require( 'php' ),
 /**
  * Stores/retrieves user PHP session data from memcached
  */
-module.exports = Class.extend( require( 'events' ).EventEmitter,
+module.exports = Class.extend( require( '../../events' ).EventEmitter,
 {
     /**
      * Session id

src/step/Step.js

@@ -26,7 +26,7 @@
  */
 
 var Class        = require( 'easejs' ).Class,
-    EventEmitter = require( 'events' ).EventEmitter,
+    EventEmitter = require( '../events' ).EventEmitter,
 
     // XXX: tightly coupled
     MultiSort = require( '../sort/MultiSort' );

src/ui/Ui.js

@@ -27,7 +27,7 @@
  */
 
 var Class        = require( 'easejs' ).Class,
-    EventEmitter = require( 'events' ).EventEmitter;
+    EventEmitter = require( '../events' ).EventEmitter;
 
 // XXX: decouple
 var DynamicContext = require( './context/DynamicContext' );

src/ui/UiStyler.js

@@ -20,7 +20,7 @@
  */
 
 var Class        = require( 'easejs' ).Class,
-    EventEmitter = require( 'events' ).EventEmitter;
+    EventEmitter = require( '../events' ).EventEmitter;
 
 
 /**

src/ui/context/DomContext.js

@@ -22,7 +22,7 @@
 var Class   = require( 'easejs' ).Class,
     Context = require( './Context' ),
 
-    EventEmitter = require( 'events' ).EventEmitter;
+    EventEmitter = require( '../../events' ).EventEmitter;
 
 
 /**

src/ui/field/DomField.js

@@ -22,7 +22,7 @@
 var Class                 = require( 'easejs' ).Class,
     Field                 = require( '../../field/Field' ),
     DomFieldNotFoundError = require( './DomFieldNotFoundError' ),
-    EventEmitter          = require( 'events' ).EventEmitter;
+    EventEmitter          = require( '../../events' ).EventEmitter;
 
 
 module.exports = Class( 'DomField' )

src/ui/group/GroupUi.js

@@ -27,7 +27,7 @@
  */
 
 var Class        = require( 'easejs' ).Class,
-    EventEmitter = require( 'events' ).EventEmitter;
+    EventEmitter = require( '../../events' ).EventEmitter;
 
 
 /**

src/ui/nav/UiNavBar.js

@@ -20,7 +20,7 @@
  */
 
 var Class        = require( 'easejs' ).Class,
-    EventEmitter = require( 'events' ).EventEmitter;
+    EventEmitter = require( '../../events' ).EventEmitter;
 
 
 /**

src/ui/sidebar/Sidebar.js

@@ -22,7 +22,7 @@
  */
 
 var Class        = require( 'easejs' ).Class,
-    EventEmitter = require( 'events' ).EventEmitter;
+    EventEmitter = require( '../../events' ).EventEmitter;
 
 
 module.exports = Class( 'Sidebar' )

src/ui/step/GeneralStepUi.js

@@ -33,7 +33,7 @@
  */
 
 var Class        = require( 'easejs' ).Class,
-    EventEmitter = require( 'events' ).EventEmitter,
+    EventEmitter = require( '../../events' ).EventEmitter,
     StepUi       = require( './StepUi' );
 
 

src/ui/step/StepUiBuilder.js

@@ -28,7 +28,7 @@
  */
 
 var Class        = require( 'easejs' ).Class,
-    EventEmitter = require( 'events' ).EventEmitter;
+    EventEmitter = require( '../../events' ).EventEmitter;
 
 
 module.exports = Class( 'StepUiBuilder' )

src/validate/ValidStateMonitor.js

@@ -22,7 +22,7 @@
 "use strict";
 
 const Class        = require( 'easejs' ).Class;
-const EventEmitter = require( 'events' ).EventEmitter;
+const EventEmitter = require( '../events' ).EventEmitter;
 const Failure      = require( './Failure' );
 const Store        = require( '../store/Store' );