Testing with Custom or auto Port

[ad-manish]

We are developing multiple services using Bun+Hono on the local system and therefore we need the application to assign port automatically based on availability, or a way to provide a custom port number.

When i following the document to assign custom port number, the test case starts failing, please suggest the solution.

// export default app --> test cases works since they are using app.request

export default {  
  port: 4000, 
  fetch: app.fetch, 
} 

but if i am not exporting the app in favour of custom port number, test does not work.