test: add test for listfiles util (#1607)

Co-authored-by: KunalNasa <kunalnasa.dev@gmail.com>
Co-authored-by: Lukasz Gornicki <lpgornicki@gmail.com>

Author: KunalNasa

packages/helpers/test/utils.test.js

@@ -1,6 +1,7 @@
 const path = require('path');
 const { Parser, fromFile } = require('@asyncapi/parser');
-const { getClientName, getInfo, getTitle, toSnakeCase } = require('@asyncapi/generator-helpers');
+const { getClientName, getInfo, getTitle, toSnakeCase, listFiles } = require('@asyncapi/generator-helpers');
+const fs = require('fs/promises');
 
 const parser = new Parser();
 const asyncapi_v3_path = path.resolve(__dirname, './__fixtures__/asyncapi-websocket-query.yml');
@@ -153,4 +154,35 @@ describe('toSnakeCase integration test with AsyncAPI', () => {
     const expectedOperationId = '';
     expect(actualOperationId).toBe(expectedOperationId);
   });
-});
+});
+
+jest.mock('fs/promises');
+describe('listFiles', () => {
+  afterEach(() => {
+    jest.clearAllMocks();
+  });
+
+  it('should return only file names from the directory', async () => {
+    const mockDirents = [
+      { name: 'file1.txt', isFile: () => true },
+      { name: 'file2.js', isFile: () => true },
+      { name: 'subdir', isFile: () => false },
+    ];
+
+    fs.readdir.mockResolvedValue(mockDirents);
+    const mockPath = '/mock/path';
+
+    const result = await listFiles(mockPath);
+    expect(fs.readdir).toHaveBeenCalledWith(mockPath, { withFileTypes: true });
+    expect(result).toEqual(['file1.txt', 'file2.js']);
+  });
+
+  it('should return an empty array if no files exist', async () => {
+    fs.readdir.mockResolvedValue([
+      { name: 'folder', isFile: () => false },
+    ]);
+    const mockPath = '/mock/path';
+    const result = await listFiles(mockPath);
+    expect(result).toEqual([]);
+  });
+});