Custom configuration for consumer and producer (#70)

* Unit test for publishing message bigger than default 1MB

* Add custom producer and consumer properties

* Update readme file with information about custom config properties

* Clean code fixes

Author: kalondar

README.md

@@ -77,6 +77,30 @@ class MySpec extends WordSpec with EmbeddedKafka {
 
 }
 ```
+
+The same implicit `EmbeddedKafkaConfig` is used to define custom consumer or producer properties
+
+```scala
+class MySpec extends WordSpec with EmbeddedKafka {
+
+"runs with custom producer and consumer properties" should {
+    val customBrokerConfig = Map("replica.fetch.max.bytes" -> "2000000",
+        "message.max.bytes" -> "2000000")
+        
+    val customProducerConfig = Map("max.request.size" -> "2000000")
+    val customConsumerConfig = Map("max.partition.fetch.bytes" -> "2000000")
+
+    implicit val customKafkaConfig = EmbeddedKafkaConfig(
+        customBrokerProperties = customBrokerConfig,
+        customProducerProperties = customProducerConfig,
+        customConsumerProperties = customConsumerConfig)
+
+    withRunningKafka {
+        // now a kafka broker is listening on port 12345
+    }
+
+}
+```
 
 This works for both `withRunningKafka` and `EmbeddedKafka.start()`
 

embedded-kafka/src/main/scala/net/manub/embeddedkafka/EmbeddedKafka.scala

@@ -219,7 +219,7 @@ sealed trait EmbeddedKafkaSupport {
     ProducerConfig.BOOTSTRAP_SERVERS_CONFIG -> s"localhost:${config.kafkaPort}",
     ProducerConfig.MAX_BLOCK_MS_CONFIG -> 10000.toString,
     ProducerConfig.RETRY_BACKOFF_MS_CONFIG -> 1000.toString
-  )
+  ) ++ config.customProducerProperties
 
   private def baseConsumerConfig(
       implicit config: EmbeddedKafkaConfig): Properties = {
@@ -228,6 +228,7 @@ sealed trait EmbeddedKafkaSupport {
     props.put("bootstrap.servers", s"localhost:${config.kafkaPort}")
     props.put("auto.offset.reset", "earliest")
     props.put("enable.auto.commit", "false")
+    props.putAll(config.customConsumerProperties)
     props
   }
 

embedded-kafka/src/main/scala/net/manub/embeddedkafka/EmbeddedKafkaConfig.scala

@@ -2,8 +2,9 @@ package net.manub.embeddedkafka
 
 case class EmbeddedKafkaConfig(kafkaPort: Int = 6001,
                                zooKeeperPort: Int = 6000,
-                               customBrokerProperties: Map[String, String] =
-                                 Map.empty)
+                               customBrokerProperties: Map[String, String] = Map.empty,
+                               customProducerProperties: Map[String, String] = Map.empty,
+                               customConsumerProperties: Map[String, String] = Map.empty)
 
 object EmbeddedKafkaConfig {
   implicit val defaultConfig = EmbeddedKafkaConfig()

embedded-kafka/src/test/scala/net/manub/embeddedkafka/EmbeddedKafkaCustomConfigSpec.scala

@@ -0,0 +1,34 @@
+package net.manub.embeddedkafka
+
+import scala.language.postfixOps
+
+class EmbeddedKafkaCustomConfigSpec extends EmbeddedKafkaSpecSupport with EmbeddedKafka {
+  val TwoMegabytes = 2097152
+  val ThreeMegabytes = 3145728
+
+  "the custom config" should {
+    "allow pass additional producer parameters" in {
+      val customBrokerConfig = Map(
+        "replica.fetch.max.bytes" -> s"$ThreeMegabytes",
+        "message.max.bytes" -> s"$ThreeMegabytes")
+
+      val customProducerConfig = Map("max.request.size" -> s"$ThreeMegabytes")
+      val customConsumerConfig = Map("max.partition.fetch.bytes" -> s"$ThreeMegabytes")
+
+      implicit val customKafkaConfig = EmbeddedKafkaConfig(
+        customBrokerProperties = customBrokerConfig,
+        customProducerProperties = customProducerConfig,
+        customConsumerProperties = customConsumerConfig)
+
+      val bigMessage = generateMessageOfLength(TwoMegabytes)
+      val topic = "big-message-topic"
+
+      withRunningKafka {
+        publishStringMessageToKafka(topic, bigMessage)
+        consumeFirstStringMessageFrom(topic) shouldBe bigMessage
+      }
+    }
+  }
+
+  def generateMessageOfLength(length: Int): String = Stream.continually(util.Random.nextPrintableChar) take length mkString
+}