Add a Test Suite for the project

Right now there isn't any test environment for the project. Testing is a vital part for any project's functionality check.

Begin by inspecting the repository structure and existing JavaScript setup to determine whether a test runner or test configuration already exists. The issue does not name target files, behavior to cover, or a test framework, so clarify the intended scope before starting. Done would require an agreed test environment and tests covering the project's intended functionality.

Written by the indexing model from the issue text.