This issue depends on stryker-mutator/mutation-testing-elements#2434

Realtime Reporting

Add support for realtime reporting in the HTML reporter in StrykerJS

Implementation

1. When all mutants have been created, open the file in the browser with its initial state.
2. After opening the HTML file, open an endpoint with the text/event-stream header.
3. When a mutant is tested, send an event to the browser. This event should at least contain a mutant id and the new status.
   a. It might also be nice to put these mutants in a list, and output them when a client is connected. This could be used to prevent missing mutant data in the browser.
4. When mutation testing is done, send a different event so that the report knows it won't recieve any new updates.
5. Finally write the complete version to disk (as we currently do).

Question(s)

1. Is there currently a way to open the report automatically in the browser?
2. Should this functionality be behind a flag, like in Stryker.NET (-o, opens the browser automatically)?
3. Should we implement this with the built-in http module or should we use express for this?