fix(NODE-5102): fix listDatabases nameOnly setting is sent as NaN

src/operations/command.ts

@@ -86,7 +86,7 @@ export abstract class CommandOperation<T> extends AbstractOperation<T> {
       this.ns = new MongoDBNamespace(dbNameOverride, '$cmd');
     } else {
       this.ns = parent
-        ? parent.s.namespace.withCollection('$cmd')
+        ? parent.s?.namespace.withCollection('$cmd')
         : new MongoDBNamespace('admin', '$cmd');
     }
 

src/operations/list_databases.ts

@@ -31,6 +31,7 @@ export class ListDatabasesOperation extends CommandOperation<ListDatabasesResult
   constructor(db: Db, options?: ListDatabasesOptions) {
     super(db, options);
     this.options = options ?? {};
+    this.options.nameOnly = !!this.options.nameOnly;
     this.ns = new MongoDBNamespace('admin', '$cmd');
   }
 
@@ -39,10 +40,7 @@ export class ListDatabasesOperation extends CommandOperation<ListDatabasesResult
     session: ClientSession | undefined,
     callback: Callback<ListDatabasesResult>
   ): void {
-    const cmd: Document = { listDatabases: 1 };
-    if (this.options.nameOnly) {
-      cmd.nameOnly = Number(cmd.nameOnly);
-    }
+    const cmd: Document = { listDatabases: 1, nameOnly: this.options.nameOnly };
 
     if (this.options.filter) {
       cmd.filter = this.options.filter;

test/unit/operations/list_databases.test.js

@@ -0,0 +1,36 @@
+'use strict';
+
+const { expect } = require('chai');
+
+const { ListDatabasesOperation } = require('../../mongodb');
+
+describe('ListDatabasesOperation', function () {
+  const db = 'test';
+
+  describe('#constructor', function () {
+    context('when nameOnly is provided', function () {
+      context('when nameOnly is true', function () {
+        const operation = new ListDatabasesOperation(db, { nameOnly: true });
+        it('sets nameOnly to true', function () {
+          expect(operation.options).to.have.property('nameOnly', true);
+        });
+      });
+
+      context('when nameOnly is false', function () {
+        const operation = new ListDatabasesOperation({}, { nameOnly: false });
+
+        it('sets nameOnly to false', function () {
+          expect(operation.options).to.have.property('nameOnly', false);
+        });
+      });
+    });
+
+    context('when no options are provided', function () {
+      const operation = new ListDatabasesOperation(db, {});
+
+      it('sets nameOnly to false', function () {
+        expect(operation.options).to.have.property('nameOnly', false);
+      });
+    });
+  });
+});