Watch file changed to build automatically?

[cwtuan]

Currently, we have to build the source manually and start http-server.
Is it possible to watch file changed to build automatically?

[cwtuan]

After @executing npm run watch in the root of this project, I saw it start to compilation when file (ex. src/ghedit/navbar.ts) changed. But after refreshing page, nothing changed.

[14:36:30] Starting compilation...
[14:36:30] Finished compilation with 0 errors after 177 ms

@scottlu @deep108 @darrinm Please help me to resolve this issue, thank you.