feat!: Options object precedence over URI options (#2691)

Author: nbbeeken

src/connection_string.ts

@@ -344,12 +344,12 @@ export function parseOptions(
 
   for (const key of allKeys) {
     const values = [];
-    if (urlOptions.has(key)) {
-      values.push(...urlOptions.get(key));
-    }
     if (objectOptions.has(key)) {
       values.push(objectOptions.get(key));
     }
+    if (urlOptions.has(key)) {
+      values.push(...urlOptions.get(key));
+    }
     if (DEFAULT_OPTIONS.has(key)) {
       values.push(DEFAULT_OPTIONS.get(key));
     }

src/mongo_client.ts

@@ -242,6 +242,9 @@ const kOptions = Symbol('options');
  * The **MongoClient** class is a class that allows for making Connections to MongoDB.
  * @public
  *
+ * @remarks
+ * The programmatically provided options take precedent over the URI options.
+ *
  * @example
  * ```js
  * // Connect using a MongoClient instance
@@ -439,6 +442,9 @@ export class MongoClient extends EventEmitter {
   /**
    * Connect to MongoDB using a url
    *
+   * @remarks
+   * The programmatically provided options take precedent over the URI options.
+   *
    * @see https://docs.mongodb.org/manual/reference/connection-string/
    */
   static connect(url: string): Promise<MongoClient>;

test/unit/mongo_client_options.test.js

@@ -16,11 +16,11 @@ describe('MongoOptions', function () {
     expect(client.options).to.be.frozen;
   });
 
-  it('test simple', function () {
+  it('programmatic options should override URI options', function () {
     const options = parseOptions('mongodb://localhost:27017/test?directConnection=true', {
       directConnection: false
     });
-    expect(options.directConnection).to.be.true;
+    expect(options.directConnection).to.be.false;
     expect(options.hosts).has.length(1);
     expect(options.dbName).to.equal('test');
     expect(options.prototype).to.not.exist;