refactor(change-stream): rename data event to change

Author: mbroadst

lib/change_stream.js

@@ -18,7 +18,7 @@ var cursorOptionNames = ['maxAwaitTimeMS', 'collation', 'readPreference'];
  * @param {object} [options.collation=null] Specify collation settings for operation. See {@link https://docs.mongodb.com/manual/reference/command/aggregate|aggregation documentation}.
  * @param {ReadPreference} [options.readPreference=null] The read preference. Defaults to the read preference of the database or collection. See {@link https://docs.mongodb.com/manual/reference/read-preference|read preference documentation}.
  * @fires ChangeStream#close
- * @fires ChangeStream#data
+ * @fires ChangeStream#change
  * @fires ChangeStream#end
  * @fires ChangeStream#error
  * @return {ChangeStream} a ChangeStream instance.
@@ -45,23 +45,23 @@ var ChangeStream = function(collection, pipeline, options) {
   self.serverConfig = collection.s.db.serverConfig;
 
   // Determine correct read preference
-  self.options.readPreference = self.options.readPreference || collection.s.readPreference;
+  // self.options.readPreference = self.options.readPreference || collection.s.readPreference;
 
   // Create contained Change Stream cursor
   self.cursor = createChangeStreamCursor(self);
 
-  // Listen for any data listeners being added to ChangeStream
+  // Listen for any `change` listeners being added to ChangeStream
   self.on('newListener', function(eventName) {
-    if (eventName === 'data' && self.cursor && self.cursor.listenerCount('data') === 0) {
+    if (eventName === 'change' && self.cursor && self.cursor.listenerCount('change') === 0) {
       self.cursor.on('data', function (change) {
         processNewChange(self, null, change);
       });
     }
   });
 
-  // Listen for all data listeners being removed from ChangeStream
+  // Listen for all `change` listeners being removed from ChangeStream
   self.on('removeListener', function(eventName){
-    if (eventName === 'data' && self.listenerCount('data') === 0 && self.cursor) {
+    if (eventName === 'change' && self.listenerCount('change') === 0 && self.cursor) {
       self.cursor.removeAllListeners('data');
     }
   });
@@ -78,12 +78,12 @@ var createChangeStreamCursor = function (self) {
     buildChangeStreamAggregationCommand(self.serverConfig, self.namespace, self.pipeline, self.resumeToken, self.options);
 
   /**
-   * Fired for each new matching change in the specified namespace. Attaching a 'data' event listener to a Change Stream will switch the stream into flowing mode. Data will then be passed as soon as it is available.
+   * Fired for each new matching change in the specified namespace. Attaching a `change` event listener to a Change Stream will switch the stream into flowing mode. Data will then be passed as soon as it is available.
    *
-   * @event ChangeStream#data
+   * @event ChangeStream#change
    * @type {object}
    */
-  if (self.listenerCount('data') > 0) {
+  if (self.listenerCount('change') > 0) {
     changeStreamCursor.on('data', function (change) {
       processNewChange(self, null, change);
     });
@@ -123,13 +123,13 @@ var createChangeStreamCursor = function (self) {
 };
 
 var buildChangeStreamAggregationCommand = function (serverConfig, namespace, pipeline, resumeToken, options) {
-  var changeNotificationStageOptions = {};
+  var changeStreamStageOptions = {};
   if (options.fullDocument) {
-    changeNotificationStageOptions.fullDocument = options.fullDocument;
+    changeStreamStageOptions.fullDocument = options.fullDocument;
   }
 
   if (resumeToken || options.resumeAfter) {
-    changeNotificationStageOptions.resumeAfter = resumeToken || options.resumeAfter;
+    changeStreamStageOptions.resumeAfter = resumeToken || options.resumeAfter;
   }
 
   // Map cursor options
@@ -141,7 +141,7 @@ var buildChangeStreamAggregationCommand = function (serverConfig, namespace, pip
   });
 
   var changeStreamPipeline = [
-    { $changeNotification: changeNotificationStageOptions }
+    { $changeStream: changeStreamStageOptions }
   ];
 
   changeStreamPipeline = changeStreamPipeline.concat(pipeline);
@@ -280,6 +280,7 @@ var processNewChange = function (self, err, change, callback) {
   if (err) {
     // Handle resumable MongoNetworkErrors
     if (err instanceof MongoNetworkError && !self.attemptingResume) {
+
       self.attemptingResume = true;
       return self.cursor.close(function(closeErr) {
         if (closeErr) {
@@ -321,7 +322,7 @@ var processNewChange = function (self, err, change, callback) {
 
   // Return the change
   if (typeof callback === 'function') return callback(err, change);
-  if (self.listenerCount('data')) return self.emit('data', change);
+  if (self.listenerCount('change')) return self.emit('change', change);
   return self.promiseLibrary.resolve(change);
 };