How to disable the web security in firefox
Don't. It gives unrealistic results for testing.
how to solve CORS issue in Firefox during development
Ideally: Create a development environment that is just like the live environment.
The server side code will, at some point, need development work performed on it. Your team will need the ability to create a development server with test data in it for that. Use the same development server for working on the client side code.
That way you can do you development work:
- without making test calls to the live server (so you never need fake test users doing fake actions on the live server with the risk that test data will escape somewhere end users will see it).
- without cross origin issues (because your development server for your client side code will be the same as the development server for the URL you are requesting)
- able to use relative URLs
- with a browser that acts like the browsers used by end users
As a quick and dirty hack which doesn't have most of the benefits of using a proper test environment: Use a proxy server that maps requests to the same origin as your development environment to the live environment.
I used Charles proxy for that before I moved to having proper development environments.