feat(urlParser): default useNewUrlParser to true

* feat(UrlParser): default useNewUrlParser to true
* a patch that fixes the readPreference issue
* fix(urlParser): defaultDatabase should be test

lib/core/uri_parser.js

@@ -534,6 +534,10 @@ function parseConnectionString(uri, options, callback) {
     if (parsedOptions.auth.username) auth.username = parsedOptions.auth.username;
     if (parsedOptions.auth.user) auth.username = parsedOptions.auth.user;
     if (parsedOptions.auth.password) auth.password = parsedOptions.auth.password;
+  } else {
+    if (parsedOptions.username) auth.username = parsedOptions.username;
+    if (parsedOptions.user) auth.username = parsedOptions.user;
+    if (parsedOptions.password) auth.password = parsedOptions.password;
   }
 
   if (cap[4].split('?')[0].indexOf('@') !== -1) {
@@ -551,8 +555,8 @@ function parseConnectionString(uri, options, callback) {
       return callback(new MongoParseError('Unescaped colon in authority section'));
     }
 
-    auth.username = qs.unescape(authParts[0]);
-    auth.password = authParts[1] ? qs.unescape(authParts[1]) : null;
+    if (!auth.username) auth.username = qs.unescape(authParts[0]);
+    if (!auth.password) auth.password = authParts[1] ? qs.unescape(authParts[1]) : null;
   }
 
   let hostParsingError = null;
@@ -617,6 +621,8 @@ function parseConnectionString(uri, options, callback) {
 
   if (result.auth && result.auth.db) {
     result.defaultDatabase = result.auth.db;
+  } else {
+    result.defaultDatabase = 'test';
   }
 
   try {

lib/mongo_client.js

@@ -140,7 +140,7 @@ const CloseOperation = require('./operations/close');
  * @param {boolean} [options.auto_reconnect=true] Enable auto reconnecting for single server instances
  * @param {boolean} [options.monitorCommands=false] Enable command monitoring for this client
  * @param {number} [options.minSize] If present, the connection pool will be initialized with minSize connections, and will never dip below minSize connections
- * @param {boolean} [options.useNewUrlParser=false] Determines whether or not to use the new url parser. Enables the new, spec-compliant, url parser shipped in the core driver. This url parser fixes a number of problems with the original parser, and aims to outright replace that parser in the near future.
+ * @param {boolean} [options.useNewUrlParser=true] Determines whether or not to use the new url parser. Enables the new, spec-compliant, url parser shipped in the core driver. This url parser fixes a number of problems with the original parser, and aims to outright replace that parser in the near future. Defaults to true, and must be explicitly set to false to use the legacy url parser.
  * @param {boolean} [options.useUnifiedTopology] Enables the new unified topology layer
  * @param {AutoEncryptionOptions} [options.autoEncryption] Optionally enable client side auto encryption
  * @param {MongoClient~connectCallback} [callback] The command result callback

lib/operations/connect.js

@@ -260,8 +260,10 @@ function connect(mongoClient, url, options, callback) {
     return connectWithUrl(mongoClient, url, options, connectCallback);
   }
 
-  const parseFn = options.useNewUrlParser ? parse : legacyParse;
-  const transform = options.useNewUrlParser ? transformUrlOptions : legacyTransformUrlOptions;
+  const useNewUrlParser = options.useNewUrlParser !== false;
+
+  const parseFn = useNewUrlParser ? parse : legacyParse;
+  const transform = useNewUrlParser ? transformUrlOptions : legacyTransformUrlOptions;
 
   parseFn(url, options, (err, _object) => {
     // Do not attempt to connect if parsing error
@@ -278,6 +280,7 @@ function connect(mongoClient, url, options, callback) {
     if (_finalOptions.connectTimeoutMS == null) _finalOptions.connectTimeoutMS = 30000;
     if (_finalOptions.retryWrites == null) _finalOptions.retryWrites = true;
     if (_finalOptions.useRecoveryToken == null) _finalOptions.useRecoveryToken = true;
+    if (_finalOptions.readPreference == null) _finalOptions.readPreference = 'primary';
 
     if (_finalOptions.db_options && _finalOptions.db_options.auth) {
       delete _finalOptions.db_options.auth;
@@ -650,16 +653,16 @@ function transformUrlOptions(_object) {
     object.dbName = _object.defaultDatabase;
   }
 
-  if (object.maxpoolsize) {
-    object.poolSize = object.maxpoolsize;
+  if (object.maxPoolSize) {
+    object.poolSize = object.maxPoolSize;
   }
 
-  if (object.readconcernlevel) {
-    object.readConcern = new ReadConcern(object.readconcernlevel);
+  if (object.readConcernLevel) {
+    object.readConcern = new ReadConcern(object.readConcernLevel);
   }
 
-  if (object.wtimeoutms) {
-    object.wtimeout = object.wtimeoutms;
+  if (object.wTimeoutMS) {
+    object.wtimeout = object.wTimeoutMS;
   }
 
   if (_object.srvHost) {

test/functional/mongo_client_tests.js

@@ -435,7 +435,7 @@ describe('MongoClient', function() {
       const client = configuration.newClient('user:password@localhost:27017/test');
 
       client.connect(function(err) {
-        test.equal(err.message, 'Invalid schema, expected `mongodb` or `mongodb+srv`');
+        expect(err).to.exist.and.to.have.property('message', 'Invalid connection string');
         done();
       });
     }