content: /*
   * 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 com.datastax.oss.driver.internal.core.channel;
  
  import static org.assertj.core.api.Assertions.assertThat;
  
  import com.datastax.oss.protocol.internal.Frame;
  import com.datastax.oss.protocol.internal.Message;
  import io.netty.channel.embedded.EmbeddedChannel;
  import java.util.Collections;
  import org.junit.Before;
  
  /**
   * Infrastructure for channel handler test.
   *
   * <p>It relies on an embedded channel where the tested handler is installed. Then the test can
   * simulate incoming/outgoing messages, and check that the handler propagates the adequate messages
   * upstream/downstream.
   */
  public class ChannelHandlerTestBase {
    protected EmbeddedChannel channel;
  
    @Before
    public void setup() {
      channel = new EmbeddedChannel();
    }
  
    /** Reads a request frame that we expect the tested handler to have sent inbound. */
    protected Frame readInboundFrame() {
      channel.runPendingTasks();
      Object o = channel.readInbound();
      assertThat(o).isInstanceOf(Frame.class);
      return ((Frame) o);
    }
  
    /** Reads a request frame that we expect the tested handler to have sent outbound. */
    protected Frame readOutboundFrame() {
      channel.runPendingTasks();
      Object o = channel.readOutbound();
      assertThat(o).isInstanceOf(Frame.class);
      return ((Frame) o);
    }
  
    protected void assertNoOutboundFrame() {
      channel.runPendingTasks();
      Object o = channel.readOutbound();
      assertThat(o).isNull();
    }
  
    /** Writes a response frame for the tested handler to read. */
    protected void writeInboundFrame(Frame responseFrame) {
      channel.writeInbound(responseFrame);
    }
  
    /** Writes a response frame that matches the given request, with the given response message. */
    protected void writeInboundFrame(Frame requestFrame, Message response) {
      channel.writeInbound(buildInboundFrame(requestFrame, response));
    }
  
    /** Builds a response frame matching a request frame. */
    protected Frame buildInboundFrame(Frame requestFrame, Message response) {
      return Frame.forResponse(
          requestFrame.protocolVersion,
          requestFrame.streamId,
          null,
          requestFrame.customPayload,
          Collections.emptyList(),
          response);
    }
  }
  