KAFKA-3621; Add tests for ApiVersionRequest/Response

Author: Ashish Singh <asingh@cloudera.com>

Reviewers: Ismael Juma <ismael@juma.me.uk>

Closes #1275 from SinghAsDev/KAFKA-3621

core/src/test/scala/unit/kafka/server/ApiVersionsRequestTest.scala

@@ -0,0 +1,50 @@
+/**
+  * Licensed to the Apache Software Foundation (ASF) under one or more
+  * contributor license agreements.  See the NOTICE file distributed with
+  * this work for additional information regarding copyright ownership.
+  * The ASF licenses this file to You under the Apache License, Version 2.0
+  * (the "License"); you may not use this file except in compliance with
+  * the License.  You may obtain a copy of the License at
+  *
+  *    http://www.apache.org/licenses/LICENSE-2.0
+  *
+  * Unless required by applicable law or agreed to in writing, software
+  * distributed under the License is distributed on an "AS IS" BASIS,
+  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  * See the License for the specific language governing permissions and
+  * limitations under the License.
+  */
+
+package kafka.server
+
+import org.apache.kafka.common.protocol.ApiKeys
+import org.apache.kafka.common.requests.ApiVersionsResponse.ApiVersion
+import org.apache.kafka.common.requests.{ApiVersionsRequest, ApiVersionsResponse}
+import org.junit.Assert._
+import org.junit.Test
+
+import scala.collection.JavaConversions._
+
+class ApiVersionsRequestTest extends BaseRequestTest {
+
+  override def numBrokers: Int = 1
+
+  @Test
+  def testApiVersionsRequest() {
+    val apiVersionsResponse = sendApiVersionsRequest(new ApiVersionsRequest, 0)
+
+    assertEquals("API keys in ApiVersionsResponse must match API keys supported by broker.", ApiKeys.values.length, apiVersionsResponse.apiVersions.size)
+    for (expectedApiVersion: ApiVersion <- KafkaApis.apiVersionsResponse.apiVersions) {
+      val actualApiVersion = apiVersionsResponse.apiVersion(expectedApiVersion.apiKey)
+      assertNotNull(s"API key ${actualApiVersion.apiKey} is supported by broker, but not received in ApiVersionsResponse.", actualApiVersion)
+      assertEquals("API key must be supported by the broker.", expectedApiVersion.apiKey, actualApiVersion.apiKey)
+      assertEquals(s"Received unexpected min version for API key ${actualApiVersion.apiKey}.", expectedApiVersion.minVersion, actualApiVersion.minVersion)
+      assertEquals(s"Received unexpected max version for API key ${actualApiVersion.apiKey}.", expectedApiVersion.maxVersion, actualApiVersion.maxVersion)
+    }
+  }
+
+  private def sendApiVersionsRequest(request: ApiVersionsRequest, version: Short): ApiVersionsResponse = {
+    val response = send(request, ApiKeys.API_VERSIONS, version)
+    ApiVersionsResponse.parse(response)
+  }
+}

core/src/test/scala/unit/kafka/server/BaseRequestTest.scala

@@ -30,11 +30,13 @@ import org.apache.kafka.common.requests.{AbstractRequest, RequestHeader, Respons
 import org.junit.Before
 
 abstract class BaseRequestTest extends KafkaServerTestHarness {
-  val numBrokers = 3
   private var correlationId = 0
 
-  // Override properties by mutating the passed Properties object
-  def propertyOverrides(properties: Properties): Unit
+  // If required, set number of brokers
+  protected def numBrokers: Int = 3
+
+  // If required, override properties by mutating the passed Properties object
+  protected def propertyOverrides(properties: Properties) {}
 
   def generateConfigs() = {
     val props = TestUtils.createBrokerConfigs(numBrokers, zkConnect, enableControlledShutdown = false)