Merge pull request #2 from kaizen-solutions/feature/readme

Improvements

Author: calvinlfer

README.md

@@ -13,10 +13,45 @@ This functionality is backed by the following libraries:
 - [FS2 kafka](https://github.com/fd4s/fs2-kafka)
 - [Confluent Schema Registry](https://github.com/confluentinc/schema-registry)
 
-### Usage ###
+### Usage
 
 Add the following to your `build.sbt`
 ```sbt
 resolvers ++= Seq("confluent" at "https://packages.confluent.io/maven")
 libraryDependencies += "io.kaizen-solutions" %% "fs2-kafka-jsonschema" % "<latest-version>"
 ```
+
+### Example
+
+Define the datatype that you would like to send/receive over Kafka via the JSON + JSON Schema format. You do this by defining your datatype and providing a `Pickler` instance for it.
+The `Pickler` instance comes from the Tapir library.
+
+```scala
+import sttp.tapir.Schema.annotations.*
+import sttp.tapir.json.pickler.*
+
+final case class Book(
+  @description("name of the book") name: String,
+  @description("international standard book number") isbn: Int
+)
+object Book:
+  given Pickler[Book] = Pickler.derived
+```
+
+Next, you can create a fs2 Kafka `Serializer` and `Deserializer` for this datatype and use it when building your FS2 Kafka producer/consumer.
+
+```scala
+import io.kaizensolutions.jsonschema.*
+import cats.effect.*
+import fs2.kafka.*
+
+def bookSerializer[F[_]: Sync]: Resource[F, ValueSerializer[F, Book]] =
+  JsonSchemaSerializerSettings.default
+    .withSchemaRegistryUrl("http://localhost:8081")
+    .forValue[F, Book]
+
+def bookDeserializer[F[_]: Sync]: Resource[F, ValueDeserializer[F, Book]] =
+  JsonSchemaDeserializerSettings.default
+    .withSchemaRegistryUrl("http://localhost:8081")
+    .forValue[F, Book]
+```

build.sbt

@@ -14,7 +14,10 @@ inThisBuild {
           ScalacOptions.unchecked,
           ScalacOptions.deprecation,
           ScalacOptions.warnValueDiscard,
+          ScalacOptions.warnUnusedImports,
           ScalacOptions.warnDeadCode,
+          ScalacOptions.warnUnusedImplicits,
+          ScalacOptions.warnUnusedExplicits,
           ScalacOptions.release("17"),
           ScalacOptions.privateKindProjector
         )

src/main/scala/io/kaizensolutions/jsonschema/JsonSchemaSerializer.scala

@@ -9,12 +9,9 @@ import io.confluent.kafka.schemaregistry.client.SchemaRegistryClient
 import io.confluent.kafka.schemaregistry.json.{JsonSchema, JsonSchemaUtils}
 import io.confluent.kafka.serializers.json.KafkaJsonSchemaSerializer
 import sttp.apispec.circe.*
-import sttp.apispec.{ExampleSingleValue, SchemaType}
 import sttp.tapir.docs.apispec.schema.*
 import sttp.tapir.json.pickler.Pickler
 
-import scala.jdk.CollectionConverters.*
-
 private[jsonschema] object JsonSchemaSerializer:
   def create[F[_], A](
     isKey: Boolean,

src/main/scala/io/kaizensolutions/jsonschema/JsonSchemaSerializerSettings.scala

@@ -2,7 +2,6 @@ package io.kaizensolutions.jsonschema
 import cats.effect.{Resource, Sync}
 import com.fasterxml.jackson.databind.ObjectMapper
 import fs2.kafka.*
-import io.circe.generic.auto
 import io.confluent.kafka.schemaregistry.SchemaProvider
 import io.confluent.kafka.schemaregistry.client.{CachedSchemaRegistryClient, SchemaRegistryClient}
 import io.confluent.kafka.schemaregistry.json.{JsonSchemaProvider, SpecificationVersion}

src/test/scala/io/kaizensolutions/jsonschema/JsonSchemaSerDesSpec.scala

@@ -4,18 +4,15 @@ import cats.effect.*
 import cats.syntax.all.*
 import fs2.Stream
 import fs2.kafka.*
-import io.confluent.kafka.schemaregistry.client.rest.exceptions.RestClientException
 import io.confluent.kafka.schemaregistry.client.{CachedSchemaRegistryClient, SchemaRegistryClient}
 import io.confluent.kafka.schemaregistry.json.JsonSchemaProvider
 import io.confluent.kafka.schemaregistry.{CompatibilityLevel, SchemaProvider}
 import io.github.embeddedkafka.schemaregistry.*
 import org.apache.kafka.common.errors.{InvalidConfigurationException, SerializationException as UnderlyingSerializationException}
-import sttp.tapir.Schema.annotations.*
 import sttp.tapir.json.pickler.Pickler
 import weaver.*
 
-import java.io.File
-import scala.concurrent.duration.DurationInt
+import scala.concurrent.duration.*
 import scala.jdk.CollectionConverters.*
 
 object JsonSchemaSerdesSpec extends IOSuite: