Code Style

In general, the best guides for code style are the Effective Dart guidelines and the linter rules set up in very_good_analysis. However, there are certain practices we’ve learned outside of these two places that will make code more maintainable.

Record Types

Among other things, the release of Dart 3.0 introduced record types, a way to store two different but related pieces of data without creating a separate data class. When using record types, be sure to choose expressive names for positional values.

Bad ❗️

Future<(String, String)> getUserNameAndEmail() async => return _someApiFetchMethod();

final userData = await getUserNameAndEmail();

// a bunch of other code...

if (userData.$1.isValid) {
  // do stuff
}

The above example will compile, but it is not immediately obvious what value userData.$1 refers to here. The name of the function gives the reader the impression that the second value in the record is the email, but it is not clear. Particularly in a large codebase, where there could be more processing in between the call to getUserNameAndEmail() and the check on userData.$1, reviewers will not be able to tell immediately what is going on here.

Good ✅

Future<(String, String)> getUserNameAndEmail() async => return _someApiFetchMethod();

final (username, email) = await getUserNameAndEmail();

// a bunch of other code...

if (email.isValid) {
  // do stuff
}

Now, we are expressly naming the values that we are getting from our record type. Any reviewer or future maintainer of this code will know what value is being validated.