[SOLVED] Uses of .devmode.js file in production mode

Uses of .devmode.js file in production mode

I have a simple GWT app. Whenever I run gwt compilation for production, I also see a file with the extension .devmode.js being generated.

Questions:

This looks like a devmode-related file; do I actually need it while running in production? Do I need to delete it?
What does it do?
If useless, is there any way to stop it from being generated while in production?

I'm using GWT 2.8.

Kind regards, Andrei

Solution

It is specific to legacy Dev Mode, and not used in Super Dev Mode. If you don't ever use legacy Dev Mode, you don't need it.

You don't need it in production... unless you ever need to debug your app in production. If you ever want to debug your app in production (with legacy dev mode), you should leave it.

You do not need to delete it - it will not be used unless you attempt to enter dev mode, and it is a static file, and cannot be used to maliciously debug your app, unless the attacker also has all of your original Java source code already.

The Linker system does not currently have a way to prevent it from being emitted. The "generation" of it is very simple, only the __MODULE_NAME__ tokens are replaced with the name of your app, so there is essentially no penalty paid in creating it.

Unless you need the extra 1k of disk space in your generated app, I wouldn't worry about it at all as there is no risk in having it. If you do need that extra 1k, either modify your current linker to avoid emitting it, or add a later build step to delete it.