state_beacon_lint 0.2.1

Linting for state_beacon users, designed to prevent common mistakes and provide a better experience.

Overview

This is the liniting package for state_beacon. It provides a set of lint rules to help you write better code and avoid some of its pitfalls.

Installation

dart pub add custom_lint state_beacon_lint --dev

# or add these lines to your pubspec.yaml
dev_dependencies:
  custom_lint:
  state_beacon_lint:

Enable the custom_lint plugin in your analysis_options.yaml file by adding the following.

analyzer:
    plugins:
        - custom_lint

NB: Create the file if it doesn't exist.

Pitfalls of state_beacon

When using Beacon.derivedFuture, only beacons accessed before the async gap(await) will be tracked as dependencies.

final counter = Beacon.writable(0);
final doubledCounter = Beacon.derived(() => counter.value * 2);

final derivedFutureCounter = Beacon.derivedFuture(() async {
  // This will be tracked as a dependency because it's accessed before the async gap
  final count = counter.value;

  await Future.delayed(Duration(seconds: count));

  // This will NOT be tracked as a dependency because it's accessed after `await`
  final doubled = doubledCounter.value;

  return '$count x 2 =  $doubled';
});

When a derivedFuture depends on multiple future/stream beacons

• DONT:

final derivedFutureCounter = Beacon.derivedFuture(() async {
  // in this instance lastNameStreamBeacon will not be tracked as a dependency
  // because it's accessed after the async gap
  final firstName = await firstNameFutureBeacon.toFuture();
  final lastName = await lastNameStreamBeacon.toFuture();

  return 'Fullname is $firstName $lastName';
});

• DO:

final derivedFutureCounter = Beacon.derivedFuture(() async {
  // acquire the futures before the async gap ie: don't use await
  final firstNameFuture = firstNameFutureBeacon.toFuture();
  final lastNameFuture = lastNameStreamBeacon.toFuture();

  // wait for the futures to complete
  final (String firstName, String lastName) = await (firstNameFuture, lastNameFuture).wait;

  return 'Fullname is $firstName $lastName';
});