Dart is an open-source, scalable programming language, with robust libraries and runtimes, for building web, server, and mobile apps.
dart2js will soon start rejecting code that uses certain deprecated language features. Right now, the compiler is warning about these language features, but it will soon reject code that uses
The compiler, dart2js, will soon start rejecting the following deprecated language features:
* Interface declarations. Use abstract classes instead.
* Getters with explicit parameter lists "()". Just remove the parentheses.
* Old-style #library, #import, and #source syntax. Convert to new-style syntax:
#import('foolib.dart', prefix: 'foo');
import 'foolib.dart' as foo;
* triple-equal operators, === and !===. Use the function "identical" instead.
* The keyword "Dynamic". Use dynamic instead (all lowercase).
You can check that your code is up to spec with the dart2js options --analyze-all and --reject-deprecated-language-features.
PS: If you're working on the platform libraries, you can use --report-sdk-use-of-deprecated language-features to see what deprecated language features the platform libraries are using.