jmx metrics: Add test timeouts and mbean server status assertions (#218)

jmx-metrics/src/test/java/io/opentelemetry/contrib/jmxmetrics/InstrumenterHelperTest.java

@@ -8,6 +8,7 @@ package io.opentelemetry.contrib.jmxmetrics;
 import static io.opentelemetry.sdk.testing.assertj.MetricAssertions.assertThat;
 import static io.opentelemetry.sdk.testing.assertj.OpenTelemetryAssertions.attributeEntry;
 import static java.lang.management.ManagementFactory.getPlatformMBeanServer;
+import static java.util.concurrent.TimeUnit.SECONDS;
 
 import groovy.lang.Closure;
 import groovy.util.Eval;
@@ -38,10 +39,12 @@ import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.Timeout;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.CsvSource;
 import org.junit.jupiter.params.provider.ValueSource;
 
+@Timeout(value = 10, unit = SECONDS)
 class InstrumenterHelperTest {
 
   private static final MBeanServer mbeanServer = getPlatformMBeanServer();
@@ -78,6 +81,11 @@ class InstrumenterHelperTest {
     jmxServer.stop();
   }
 
+  @BeforeEach
+  void confirmServerIsActive() {
+    assertThat(jmxServer.isActive()).isTrue();
+  }
+
   @BeforeEach
   void setupOtel() {
     metricReader = InMemoryMetricReader.create();

jmx-metrics/src/test/java/io/opentelemetry/contrib/jmxmetrics/MBeanHelperTest.java

@@ -6,6 +6,7 @@
 package io.opentelemetry.contrib.jmxmetrics;
 
 import static java.lang.management.ManagementFactory.getPlatformMBeanServer;
+import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.assertj.core.api.Assertions.assertThat;
 
 import java.util.Arrays;
@@ -24,8 +25,11 @@ import javax.management.remote.JMXServiceURL;
 import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.Timeout;
 
+@Timeout(value = 10, unit = SECONDS)
 class MBeanHelperTest {
 
   private static final MBeanServer mbeanServer = getPlatformMBeanServer();
@@ -56,6 +60,11 @@ class MBeanHelperTest {
     jmxServer.stop();
   }
 
+  @BeforeEach
+  void confirmServerIsActive() {
+    assertThat(jmxServer.isActive()).isTrue();
+  }
+
   @AfterEach
   void unregisterBeans() throws Exception {
     for (ObjectInstance bean : registeredBeans) {

jmx-metrics/src/test/java/io/opentelemetry/contrib/jmxmetrics/OtelHelperJmxTest.java

@@ -6,6 +6,7 @@
 package io.opentelemetry.contrib.jmxmetrics;
 
 import static java.lang.management.ManagementFactory.getPlatformMBeanServer;
+import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatCode;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
@@ -28,7 +29,9 @@ import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.Timeout;
 
+@Timeout(value = 10, unit = SECONDS)
 class OtelHelperJmxTest {
 
   private static final String thingName =
@@ -48,10 +51,15 @@ class OtelHelperJmxTest {
 
   @AfterAll
   static void tearDown() throws Exception {
-    jmxServer.stop();
     mbeanServer.unregisterMBean(new ObjectName(thingName));
   }
 
+  @AfterEach
+  void stopServer() throws Exception {
+    // each test stands up its own server
+    jmxServer.stop();
+  }
+
   @AfterEach
   void unregisterBeans() throws Exception {
     for (ObjectInstance bean : registeredBeans) {