Cover assert() in the Dart 2.0 page

[kwalrath]

In Dart 1.x, assert() works only in checked mode. But checked mode is obsolete in Dart 2.0. The Dart 2.0 Updates page should say how assert() will work in 2.0.

[chalin]

To give a bit more context, in the Assert section of the Language Tour it is written:

Note: Assert statements work only in checked mode. They have no effect in production mode.

Dart 2.0 note: Checked mode won’t be in Dart 2.0. For more information, see Dart 2.0 Updates.

@munificent, @floitschG - has it been decided how assert() will be handled in Dart 2? I'll be reworking some of the example code and I was wondering if I should drop the use of asserts in favor of something else.

cc @kevmoo @filiph

[floitschG]

We will still have a second mode to enable asserts.

I think the easiest is to call it "debug" mode.

[kwalrath]

Tracking bug: dart-lang/sdk#32255

[kwalrath]

--enable-asserts will work for dart & dart2js. dartdevc always has asserts enabled. We won't call it a separate mode, iirc, just talk about how you use asserts.

[kwalrath]

@filiph how does assert() work in Flutter?

[filiph]

Currently, assert works in debug mode, and is an important part of the developer experience (asserts are everywhere in the framework, so that you get early feedback).

I haven't checked, but I assume in release mode asserts are off. Paging @Hixie to confirm that this is the case and that it won't change in the foreseeable future.

[Hixie]

yeah i don't expect that to change.