Add simple unit tests for MqttBrokerConfigBuilder class.

src/test/java/cool/mqtt/hooks/utils/MqttBrokerConfigBuilderTest.java

@@ -0,0 +1,97 @@
+package cool.mqtt.hooks.utils;
+
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.CoreMatchers.notNullValue;
+import static org.hamcrest.CoreMatchers.nullValue;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+import cool.mqtt.hooks.MqttBrokerConfig;
+import cool.mqtt.hooks.MqttMessage;
+import cool.mqtt.hooks.QoS;
+import cool.mqtt.hooks.utils.MqttBrokerConfigBuilder;
+
+public class MqttBrokerConfigBuilderTest {
+
+  @Rule
+  public ExpectedException thrown = ExpectedException.none();
+
+  private MqttBrokerConfigBuilder builder;
+
+  @Before
+  public void setup() {
+    builder = new MqttBrokerConfigBuilder("tcp://localhost:1883");
+  }
+
+  @Test
+  public void shouldBuildConfigWithDefaultValues() {
+    MqttBrokerConfig config = builder.build();
+    assertThat(config.getAddress(), is("tcp://localhost:1883"));
+    assertThat(config.getClientIdPrefix(), nullValue());
+    assertThat(config.getConnectionTimeout(), nullValue());
+    assertThat(config.getKeepAlive(), nullValue());
+    assertThat(config.getPassword(), nullValue());
+    assertThat(config.getUsername(), nullValue());
+    assertThat(config.getPassword(), nullValue());
+    assertThat(config.getWillMessage(), nullValue());
+  }
+
+  @Test
+  public void shouldBuildConfigWithCustomValues() {
+    MqttBrokerConfig config = builder
+      .username("username")
+      .password("password")
+      .clientIdPrefix("client_id_prefix")
+      .connectionTimeout(5)
+      .keepAlive(10)
+      .willMessage("topic", new byte[] { 1, 2, 3 }, QoS.AT_MOST_ONCE,
+        true)
+      .build();
+
+    assertThat(config.getAddress(), is("tcp://localhost:1883"));
+    assertThat(config.getClientIdPrefix(), is("client_id_prefix"));
+    assertThat(config.getConnectionTimeout(), is(5));
+    assertThat(config.getKeepAlive(), is(10));
+    assertThat(config.getPassword(), is("password"));
+    assertThat(config.getUsername(), is("username"));
+
+    MqttMessage willMessage = config.getWillMessage();
+    assertThat(willMessage, notNullValue());
+    assertThat(willMessage.getTopicName(), is("topic"));
+    assertThat(willMessage.getQos(), is(QoS.AT_MOST_ONCE));
+    assertThat(willMessage.getApplicationMessage(),
+      is(new byte[] { 1, 2, 3 }));
+  }
+
+  @Test
+  public void shouldThrowIllegalArgumentExceptionForInvalidNullTopic() {
+    thrown.expect(IllegalArgumentException.class);
+    thrown.expectMessage(is("Invalid topic"));
+
+    builder.willMessage(null, new byte[] { 1, 2, 3 }, QoS.AT_MOST_ONCE,
+      true);
+  }
+
+  @Test
+  public void shouldThrowIllegalArgumentExceptionForInvalidEmptyTopic() {
+    thrown.expect(IllegalArgumentException.class);
+    thrown.expectMessage(is("Invalid topic"));
+
+    builder.willMessage("", new byte[] { 1, 2, 3 }, QoS.AT_MOST_ONCE,
+      true);
+  }
+
+  @Test
+  public void shouldThrowIllegalArgumentExceptionForInvalidQoS() {
+    // Set expected exception.
+    thrown.expect(IllegalArgumentException.class);
+    thrown.expectMessage(is("Invalid QoS"));
+
+    builder.willMessage("topic", new byte[] { 1, 2, 3 }, null, false);
+  }
+
+}