feature4s

feature4s is a small library which implement the Feature Toggles pattern for scala.

Get started

libraryDependencies ++= Seq(
  "com.nryanov.feature4s" %% "<feature4s-backend>" % "[version]" 
)

import feature4s.redis.lettuce._
import io.lettuce.core.RedisClient

object Application {
  def main(args: Array[String]): Unit = {
    val client = RedisClient.create(s"redis://localhost:6379")
    val namespace = "features"
    val featureRegistry = LettuceSyncFeatureRegistry.useConnection(client.connect(), namespace)
   
    val myFeature = featureRegistry.register("featureName", enable = false, Some("description"))
   
    if (myFeature.isEnable()) {
      // if feature is enable logic
    } else {
      // if feature is disable logic    
    } 
    
    client.close()
  }
}

OpenAPI documentation

API for feature4s is build using tapir. Choose a preferred backend and json-lib and then add the following dependencies:

libraryDependencies ++= Seq(
  "com.nryanov.feature4s" %% "<feature4s-tapir-backend>" % "[version]"
  "com.nryanov.feature4s" %% "<feature4s-tapir-json>" % "[version]" 
)

Supported http servers

• akka
• http4s (+ zio-http4s)

For more information about using these servers with tapir see: doc

Supported json integrations

• circe
• json4s
• spray-json
• tethys

Json codecs for internal feature4s structures can be added like this:

import features.tapir.json.[circe/json4s/sprayjson/tethys]._

For json4s you also need to choose serialization backend: native or jackson.

libraryDependencies ++= Seq(
  "org.json4s" %% "json4s-native" % "{latestVersion}"
// or
  "org.json4s" %% "json4s-jackson" % "{latestVersion}" 
)

After that just add a format:

implicit val formats: Formats = Serialization.formats(NoTypeHints)

Examples

Hello world examples with OpenAPI docs can be found in the examples folder.

Backends

Backend	Client
Aerospike	aerospike-client-java
Redis	jedis lettuce redisson
Zookeeper	curator

Implementations

Class	Effect
InMemoryIdFeatureRegistry	None (Identity)
InMemoryCatsFeatureRegistry	F[_]: cats.effect.Concurrent
InMemoryZioFeatureRegistry	zio.Task
CachedFeatureRegistry	F[_] (wrapper for any FeatureRegistry[F[_]])
AerospikeSyncFeatureRegistry	None (Identity)
AerospikeCatsFeatureRegistry	F[_]: cats.effect.Sync: cats.effect.ContextShift
AerospikeZioFeatureRegistry	zio.Task
JedisClusterSyncFeatureRegistry	None (Identity)
JedisClusterCatsFeatureRegistry	F[_]: cats.effect.Sync: cats.effect.ContextShift
JedisClusterZioFeatureRegistry	zio.Task
JedisSyncFeatureRegistry (JedisPool && JedisSentinel)	None (Identity)
JedisCatsFeatureRegistry (JedisPool && JedisSentinel)	F[_]: cats.effect.Sync: cats.effect.ContextShift
JedisZioFeatureRegistry (JedisPool && JedisSentinel)	zio.Task
LettuceSyncFeatureRegistry	None (Identity)
LettuceAsyncFeatureRegistry	scala.concurrent.Future
LettuceCatsFeatureRegistry	F[_]: cats.effect.Sync: cats.effect.ContextShift
LettuceCatsAsyncFeatureRegistry	F[_]: cats.effect.Concurrent
LettuceZioFeatureRegistry	zio.Task
LettuceZioAsyncFeatureRegistry	zio.Task
RedissonSyncFeatureRegistry	None (Identity)
RedissonAsyncFeatureRegistry	scala.concurrent.Future
RedissonCatsFeatureRegistry	F[_]: cats.effect.Sync: cats.effect.ContextShift
RedissonCatsAsyncFeatureRegistry	F[_]: cats.effect.Concurrent
RedissonZioFeatureRegistry	zio.Task
RedissonZioAsyncFeatureRegistry	zio.Task
ZookeeperSyncFeatureRegistry	None (Identity)
ZookeeperCatsFeatureRegistry	F[_]: cats.effect.Sync: cats.effect.ContextShift
ZookeeperZioFeatureRegistry	zio.Task