Test: serviceability/dcmd/framework/InvalidCommandTest.java
---------------- stdout ----------------
985047:

---------------- stderr ----------------
java.lang.IllegalArgumentException: Unknown diagnostic command

----------------------------------------

test InvalidCommandTest.file(): success
Running DCMD 'asdf' through 'JMXExecutor'
---------------- stdout ----------------

---------------- stderr ----------------
java.lang.IllegalArgumentException: Unknown diagnostic command: asdf
at jdk.test.lib.dcmd.JMXExecutor.executeImpl(JMXExecutor.java:105)
at jdk.test.lib.dcmd.CommandExecutor.execute(CommandExecutor.java:61)
at jdk.test.lib.dcmd.CommandExecutor.execute(CommandExecutor.java:43)
at InvalidCommandTest.run(InvalidCommandTest.java:46)
at InvalidCommandTest.jmx(InvalidCommandTest.java:73)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
at java.base/java.lang.reflect.Method.invoke(Method.java:578)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:132)
at org.testng.internal.TestInvoker.invokeMethod(TestInvoker.java:599)
at org.testng.internal.TestInvoker.invokeTestMethod(TestInvoker.java:174)
at org.testng.internal.MethodRunner.runInSequence(MethodRunner.java:46)
at org.testng.internal.TestInvoker$MethodInvocationAgent.invoke(TestInvoker.java:822)
at org.testng.internal.TestInvoker.invokeTestMethods(TestInvoker.java:147)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:146)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:128)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
at org.testng.TestRunner.privateRun(TestRunner.java:764)
at org.testng.TestRunner.run(TestRunner.java:585)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:384)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:378)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:337)
at org.testng.SuiteRunner.run(SuiteRunner.java:286)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:53)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:96)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1218)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1140)
at org.testng.TestNG.runSuites(TestNG.java:1069)
at org.testng.TestNG.run(TestNG.java:1037)
at com.sun.javatest.regtest.agent.TestNGRunner.main(TestNGRunner.java:93)
at com.sun.javatest.regtest.agent.TestNGRunner.main(TestNGRunner.java:53)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
at java.base/java.lang.reflect.Method.invoke(Method.java:578)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:125)
at java.base/java.lang.Thread.run(Thread.java:1591)
Caused by: javax.management.ReflectionException
at jdk.management/com.sun.management.internal.DiagnosticCommandImpl.invoke(DiagnosticCommandImpl.java:274)
at java.management/com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:803)
at java.management/com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:802)
at jdk.test.lib.dcmd.JMXExecutor.executeImpl(JMXExecutor.java:96)
... 33 more
Caused by: java.lang.NoSuchMethodException: Method asdf with signature [[Ljava.lang.String;] not found
... 37 more

Also:
serviceability/dcmd/framework/HelpTest.java
serviceability/dcmd/framework/VMVersionTest.java