How can I enable Flutter/Dart language experiments?
Solution 1:
In my case, I have followed these two steps and It worked for me.
run "flutter upgrade"
-
changing the sdk in the environment in pubspec.yaml
environment: sdk: ">=2.6.0 <3.0.0"
Solution 2:
You need to create an analysis_options.yaml file in the root of your flutter app and write something like
analyzer:
enable-experiment:
- spread-collections
Also make sure to switch to the correct channel where the new feature is included eg (dev, beta or master)
flutter channel dev
And also make sure you have a recent enough version of flutter
flutter upgrade
Ensure you are on the right version of flutter and dart that allows that feature by running
flutter --version
you may also have to manually change your pubspec.yaml file to specify the correct dart sdk (if so rerun flutter upgrade)
environment:
sdk: ">=2.10.0-0 <3.0.0"
Solution 3:
With the new version of flutter it became an error - but it can easily be fixed by updating the sdk version:
environment:
sdk: ">=2.7.0 <3.0.0"
Just don't forget to restart VisualStudio Code or whatever IDE you're using.