docs(connection+mongoose): add useUnifiedTopology option to `connec…

…t()` and `openUri()` docs

Fix #8146

README.md

@@ -66,7 +66,10 @@ Both `connect` and `createConnection` take a `mongodb://` URI, or the parameters
 ```js
 const mongoose = require('mongoose');
 
-mongoose.connect('mongodb://localhost/my_database', {useNewUrlParser: true});
+mongoose.connect('mongodb://localhost/my_database', {
+  useNewUrlParser: true,
+  useUnifiedTopology: true
+});
 ```
 
 Once connected, the `open` event is fired on the `Connection` instance. If you're using `mongoose.connect`, the `Connection` is `mongoose.connection`. Otherwise, `mongoose.createConnection` return value is a `Connection`.

lib/connection.js

@@ -483,7 +483,8 @@ Connection.prototype.onOpen = function() {
  * @param {String} [options.user] username for authentication, equivalent to `options.auth.user`. Maintained for backwards compatibility.
  * @param {String} [options.pass] password for authentication, equivalent to `options.auth.password`. Maintained for backwards compatibility.
  * @param {Boolean} [options.autoIndex=true] Mongoose-specific option. Set to false to disable automatic index creation for all models associated with this connection.
- * @param {Boolean} [options.useNewUrlParser=false] False by default. Set to `true` to make all connections set the `useNewUrlParser` option by default.
+ * @param {Boolean} [options.useNewUrlParser=false] False by default. Set to `true` to opt in to the MongoDB driver's new URL parser logic.
+ * @param {Boolean} [options.useUnifiedTopology=false] False by default. Set to `true` to opt in to the MongoDB driver's replica set and sharded cluster monitoring engine.
  * @param {Boolean} [options.useCreateIndex=true] Mongoose-specific option. If `true`, this connection will use [`createIndex()` instead of `ensureIndex()`](/docs/deprecations.html#-ensureindex-) for automatic index builds via [`Model.init()`](/docs/api.html#model_Model.init).
  * @param {Boolean} [options.useFindAndModify=true] True by default. Set to `false` to make `findOneAndUpdate()` and `findOneAndRemove()` use native `findOneAndUpdate()` rather than `findAndModify()`.
  * @param {Number} [options.reconnectTries=30] If you're connected to a single server or mongos proxy (as opposed to a replica set), the MongoDB driver will try to reconnect every `reconnectInterval` milliseconds for `reconnectTries` times, and give up afterward. When the driver gives up, the mongoose connection emits a `reconnectFailed` event. This option does nothing for replica set connections.

lib/index.js

@@ -300,7 +300,8 @@ Mongoose.prototype.createConnection = function(uri, options, callback) {
  * @param {String} [options.user] username for authentication, equivalent to `options.auth.user`. Maintained for backwards compatibility.
  * @param {String} [options.pass] password for authentication, equivalent to `options.auth.password`. Maintained for backwards compatibility.
  * @param {Boolean} [options.autoIndex=true] Mongoose-specific option. Set to false to disable automatic index creation for all models associated with this connection.
- * @param {Boolean} [options.useNewUrlParser=false] False by default. Set to `true` to make all connections set the `useNewUrlParser` option by default.
+ * @param {Boolean} [options.useNewUrlParser=false] False by default. Set to `true` to opt in to the MongoDB driver's new URL parser logic.
+ * @param {Boolean} [options.useUnifiedTopology=false] False by default. Set to `true` to opt in to the MongoDB driver's replica set and sharded cluster monitoring engine.
  * @param {Boolean} [options.useCreateIndex=true] Mongoose-specific option. If `true`, this connection will use [`createIndex()` instead of `ensureIndex()`](/docs/deprecations.html#-ensureindex-) for automatic index builds via [`Model.init()`](/docs/api.html#model_Model.init).
  * @param {Boolean} [options.useFindAndModify=true] True by default. Set to `false` to make `findOneAndUpdate()` and `findOneAndRemove()` use native `findOneAndUpdate()` rather than `findAndModify()`.
  * @param {Number} [options.reconnectTries=30] If you're connected to a single server or mongos proxy (as opposed to a replica set), the MongoDB driver will try to reconnect every `reconnectInterval` milliseconds for `reconnectTries` times, and give up afterward. When the driver gives up, the mongoose connection emits a `reconnectFailed` event. This option does nothing for replica set connections.