Experiment flags
The Dart SDK often contains experimental features, which you can try by passing flags to Dart tools.
Using experiment flags with command-line tools
#To use an experiment with Dart SDK command line tools, pass the corresponding flag to the tool. For example, to enable the experiments super-mixins
and no-slow-checks
, add those flags to the dart
command:
$ dart run --enable-experiment=super-mixins,no-slow-checks bin/main.dart
Using experiment flags with the Dart analyzer (command-line and IDE)
#To enable experiments affecting analysis, use the enable-experiment
key in the analysis options file. Here's an example of enabling the experiments super-mixins
and no-slow-checks
in analysis_options.yaml
:
analyzer:
enable-experiment:
- super-mixins
- no-slow-checks
Using experiment flags with IDEs
#To enable experiments related to running or debugging apps in IDEs, edit the launch configuration.
Visual Studio Code
#In launch.json
under configurations
, add a new toolArgs
key containing the desired flags. Example:
"configurations": [
{
"name": "Dart",
"program": "bin/main.dart",
"request": "launch",
"type": "dart",
"toolArgs": [
"--enable-experiment=super-mixins,no-slow-checks",
],
}
]
For more information, consult the documentation for VS Code launch configurations.
Android Studio
#Under VMOptions
add the desired flags. Example:
<component name="ProjectRunConfigurationManager">
<configuration default="false" name="Run main" type="DartCommandLineRunConfigurationType" factoryName="Dart Command Line Application">
<option name="VMOptions" value="--enable-experiment=non-nullable" />
<option name="filePath" value="$PROJECT_DIR$/bin/main.dart" />
<method v="2" />
</configuration>
</component>
For more information, consult the instructions for Android Studio run/debug configurations.
More information
#- For a complete list of experiments, see the Dart SDK file
experimental_features.yaml
. - For information on procedures and expectations for experiment flags, see the documentation of the process for changes that are behind experimental flags.
Unless stated otherwise, the documentation on this site reflects Dart 3.5.3. Page last updated on 2024-04-11. View source or report an issue.