@exodus/feature-flags
Modules and atoms for monitoring/controlling the currently available features based on remoteConfig, device geolocation, etc.
Usage
We recommend you use this feature via @exodus/headless, as follows in the below example:
- Specify your feature flags when configuring the
@exodus/headlessinstance. - Consume/control feature flags:
- In your modules/atoms/plugins/features, use the
featureFlagAtomsdependency. - In the UI:
- Use the
selectors.featureFlags.create(featureFlagName)selector to read the current flag value. - Use
exodus.featureFlags.enable(featureFlagName)andexodus.featureFlags.disable(featureFlagName)if you need to toggle the flag value at runtime.
- Use the
See example code below.
background
import createExodus from '@exodus/headless';
const featureFlags = {
// ... other feature flags,
dogeMode: {
localDefaults: {
// `true` if feature is shipped (available at runtime), `false` otherwise
available: true,
// controls whether the feature is enabled by default
// NOTE: if `available` is false, `enabled` can NOT be true, or you can expect an error
enabled: true,
},
remoteConfig: {
// path to flag in remote config schema
path: 'features.dogeMode',
supportedOverrides: {
// can be enabled/disabled for all users via remote config
enabled: true,
// can be enabled/disabled for users in certain geolocations via remote config
geolocation: true,
// can be enabled/disabled for users on certain app versions via remote config
shutdownSemver: true,
},
},
},
};
const exodusContainer = createExodus({
port,
adapters,
config: {
// ...,
featureFlags,
},
});
const checkDogeModePlugin = {
id: 'checkDogeModePlugin',
factory: ({ featureFlagAtoms }) => {
const onStart = () => {
featureFlagAtoms.dogeMode?.get().then(({ isOn }) => {
console.log('>>> is dogeMode enabled?', isOn);
});
};
return {
onStart,
};
},
dependencies: ['featureFlagAtoms'],
};
exodusContainer.register({
definition: checkDogeModePlugin,
});
const exodus = exodusContainer.resolve();
// ... continue as usualUI-side
import selectors from '~/ui/flux/selectors';
const dogeModeFeatureName = 'dogeMode';
const HomePage = () => {
const dogeMode = useSelector(selectors.featureFlags.create(dogeModeFeatureName));
useEffect(() => {
if (Math.random() < 0.001) {
exodus.featureFlags.enable(dogeModeFeatureName);
}
}, [dogeMode]);
return dogeMode?.isOn ? <DogeMode /> : <NormalMode />;
};Usage examples without @exodus/headless
See the examples folder
Components
remoteConfigFeatureFlagAtoms
An atom collection { [featureName]: atom }, where each atom emits the current remote-config value for that feature flag:
{
isOn: Boolean,
unavailableStatus: ?String
}featureFlagAtoms
An atom collection { [featureName]: atom }, where each atom emits the current status of its feature flag:
{
isOn: Boolean,
unavailableStatus: ?String
}featureFlagsAtom
An atom that emits the current status of all feature flags as an object map:
{
[featureName]: {
isOn: Boolean,
unavailableStatus: ?String
}
}featureFlags
Module that overrides local values for feature flags based on remoteConfig and geolocation. It writes values to atoms in featureFlagAtoms, but it might be easier to observe the aggregate feature flags atom featureFlagsAtom.