fix(NODE-4831): check for null

Author: durran

src/cmap/connection.ts

@@ -384,8 +384,7 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
       } else {
         // Get the first orphaned operation description.
         const entry = this[kQueue].entries().next();
-        /* eslint no-restricted-syntax: 0 */
-        if (entry.value !== undefined) {
+        if (entry.value != null) {
           const [requestId, orphaned]: [number, OperationDescription] = entry.value;
           // If the orphaned operation description exists then set it.
           operationDescription = orphaned;

test/unit/cmap/connection.test.ts

@@ -311,7 +311,7 @@ describe('new Connection()', function () {
           const message = new BinMsg(msg, msgHeader, msgBody);
           expect(() => {
             connection.onMessage(message);
-          }).to.not.throw(/undefined is not iterable/);
+          }).to.not.throw();
         });
       });