feat(Update): add the ability to specify a pipeline to an update command (#2017)

* feat(Update): add the ability to specify a pipeline to an update command

NODE-1920

Author: Sam Pal

lib/collection.js

@@ -686,7 +686,15 @@ Collection.prototype.updateOne = function(filter, update, options, callback) {
   if (typeof options === 'function') (callback = options), (options = {});
   options = options || {};
 
-  const err = checkForAtomicOperators(update);
+  let err;
+  if (Array.isArray(update)) {
+    for (let i = 0; !err && i < update.length; i++) {
+      err = checkForAtomicOperators(update[i]);
+    }
+  } else {
+    err = checkForAtomicOperators(update);
+  }
+
   if (err) {
     if (typeof callback === 'function') return callback(err);
     return this.s.promiseLibrary.reject(err);

test/functional/collection_tests.js

@@ -1918,4 +1918,36 @@ describe('Collection', function() {
       client.close();
     });
   });
+
+  it('should correctly update with pipeline', {
+    metadata: {
+      requires: { mongodb: '>=4.2.0' }
+    },
+
+    // The actual test we wish to run
+    test: function(done) {
+      const configuration = this.configuration;
+      const client = configuration.newClient(configuration.writeConcernMax(), {
+        poolSize: 1
+      });
+
+      client.connect((err, client) => {
+        const db = client.db(configuration.db);
+
+        db.createCollection('test_should_correctly_do_update_with_pipeline', (err, collection) => {
+          collection.updateOne(
+            {},
+            [{ $set: { a: 1 } }, { $set: { b: 1 } }, { $set: { d: 1 } }],
+            configuration.writeConcernMax(),
+            (err, r) => {
+              expect(err).to.not.exist;
+              expect(r.result.n).to.equal(0);
+
+              client.close(done);
+            }
+          );
+        });
+      });
+    }
+  });
 });