A tool to migrate API usage to Dart 2.
Note: This tool needs to be run on a version of the Dart SDK that contains the deprecated annotations (a pre-
What does it do?
dart2_fix is a command line utility that can automatically migrate some Dart 1 API usages in your
source code to Dart 2 ones. Currently, it focuses on updating deprecated constant names; for example:
For more information about preparing your code for Dart 2, please see the Dart 2 migration guide.
How do I use it?
To install, run
pub global activate dart2_fix. Then, from your project directory, run:
pub global run dart2_fix
When run without any arguments, it will check your project, but will not make changes; it'll indicate what would be changed if asked to make modifications. For example:
test/test/runner/load_suite_test.dart line 56 • Duration.ZERO => Duration.zero line 60 • Duration.ZERO => Duration.zero line 86 • Duration.ZERO => Duration.zero test/tool/host.dart line 169 • JSON => json line 173 • JSON => json Found 5 fixes in 2.3s. To apply these fixes, run again using the --apply argument.
To actually modify your project source code, run with the
--apply argument (
pub global run dart2_fix --apply):
Updating test... test/test/runner/load_suite_test.dart 3 fixes applied for Duration.ZERO => Duration.zero test/tool/host.dart 2 fixes applied for JSON => json Applied 5 fixes in 1.9s.
What about Flutter code?
To run this tool on Flutter code, use:
flutter packages pub global activate dart2_fix
then - to check your code - run:
flutter packages pub global run dart2_fix
and to apply fixes, run:
flutter packages pub global run dart2_fix --apply
Will this make all of my code Dart 2 compliant?
No. Currently this only fixes the renaming of various deprecated constant
names. Some of the less uniform constant renamings are not handled by this
tool. For example
Endianness.BIG_ENDIAN has been renamed to
this will not be caught. After running this tool, remaining issues can be found
by running the dart analyzer (or flutter analyze) and fixing any deprecation
I'm getting new static (or runtime errors) after running dart2_fix, what went wrong?
This tool can't catch conflicts between the new constant names and any fields or
local variables that you might have in scope. If you get new analysis warnings
or runtime failures after running this tool, check to see whether one of the
changes made has caused a naming conflict with something else in scope. The
most common cause of this is having a local variable named
json in a scope
JSON.decode gets renamed to
json.decode. To help with fixing these
kinds of conflicts, the following top level members have been added to
base64UrlEncode. These top level members are equivalent to
json.decode, etc, and can be used to avoid naming conflicts where required.
Features and bugs
Please file feature requests and bugs at the issue tracker.