The issue lists specific test files to add: app.model, app.use, app.router, app.start. Since the repository is eva.js, a Vue.js solution, check the source code to understand the methods and their expected behavior. Look for existing test files or a testing framework configuration (e.g., jest, mocha) in the repository. The maintainer has not provided further details, so you may need to infer the testing approach from the project structure.
