fix(url parser): preserve auth creds when composing conn string (#1640)

Fixes NODE-1286

Author: Jessica Lord

lib/url_parser.js

@@ -48,8 +48,9 @@ module.exports = function(url, options, callback) {
       }
     }
 
+    let base = result.auth ? `mongodb://${result.auth}@` : `mongodb://`;
     let connectionStrings = addresses.map(function(address, i) {
-      if (i === 0) return `mongodb://${address.name}:${address.port}`;
+      if (i === 0) return `${base}${address.name}:${address.port}`;
       else return `${address.name}:${address.port}`;
     });
 

test/functional/dns_txt_records_tests.js test/functional/mongodb_srv_tests.jstest/functional/dns_txt_records_tests.js renamed to test/functional/mongodb_srv_tests.js

@@ -42,4 +42,23 @@ describe('DNS and TXT record tests', function() {
       }
     });
   });
+
+  it('preserves auth credentials in the connection string', {
+    metadata: {
+      requires: { topology: ['single'] }
+    },
+    test: function(done) {
+      let user = 'auser';
+      let password = 'apass';
+      let uri = `mongodb+srv://${user}:${password}@test18.test.build.10gen.cc/?replicaSet=repl0`;
+      parse(uri, function(err, object) {
+        expect(err).to.not.exist;
+        expect(object.auth.user).to.not.be.undefined;
+        expect(object.auth.user).to.equal(user);
+        expect(object.auth.password).to.not.be.undefined;
+        expect(object.auth.password).to.equal(password);
+        done();
+      });
+    }
+  });
 });