debugging - How to check flutter application is running in debug?

Question

I have a short question. I'm looking for a way to execute code in Flutter when the app is in Debug mode. Is that possible in Flutter? I can't seem to find it anywhere in the documentation.

Something like this

If(app.inDebugMode) {
   print("Print only in debug mode");
}

How to check if the flutter application is running in debug or release mode?

Answer 1

While asserts technically works, you should not use them.

Instead, use the constant kReleaseMode from package:flutter/foundation.dart

---

The difference is all about tree shaking

Tree shaking (aka the compiler removing unused code) depends on variables being constants.

The issue is, with asserts our isInReleaseMode boolean is not a constant. So when shipping our app, both the dev and release code are included.

On the other hand, kReleaseMode is a constant. Therefore the compiler is correctly able to remove unused code, and we can safely do:

if (kReleaseMode) {

} else {
  // Will be tree-shaked on release builds.
}