Writing your first test
This page will guide you through the process of writing your first test.
Creating a test class
The first step is to create a test class. The convention is to put this class in the src/test/java or src/test/kotlin directory, depending on your language of choice.
Create a new class called HelloWorldTest.java in the src/test/java directory.
TIP
Its common practice to name test classes with the Test suffix, so HelloWorldTest is a good name if you are writing a test for the HelloWorld class. The name doesn't matter, but it's a good convention. The Test suffix helps identify test classes easily, and it's recognized by most build tools and testing frameworks for running tests automatically.
WARNING
You're class can't be final. This is because MockBukkit uses reflection to modify the behavior of the class under test. In Kotlin, classes are final by default, so you must declare them as open for MockBukkit to function properly.
Here's an example of a test class
java
public class MyPluginTests {
private ServerMock server;
private MyPlugin plugin;
@BeforeEach
public void setUp() {
// Start the mock server
server = MockBukkit.mock();
// Load your plugin
plugin = MockBukkit.load(MyPlugin.class);
}
@AfterEach
public void tearDown() {
// Stop the mock server
MockBukkit.unmock();
}
@Test
public void thisTestWillFail() {
// Perform your test
}
}kotlin
class MyPluginTests {
private lateinit var server: ServerMock
private lateinit var plugin: MyPlugin
@BeforeEach
fun setUp() {
// Start the mock server
server = MockBukkit.mock()
// Load your plugin
plugin = MockBukkit.load(MyPlugin::class.java)
}
@AfterEach
fun tearDown() {
// Stop the mock server
MockBukkit.unmock()
}
@Test
fun thisTestWillFail() {
// Perform your test
}
}UnimplementedOperationException
Sometimes, you will need to test a method that is not implemented yet. When this happens, MockBukkit will throw an UnimplementedOperationException. This exception extends TestAbortedException, so it will cause the test to skip.
These can be ignored, as a skipped test will not affect the overall test result. However, we always welcome any contributions to MockBukkit that implement the missing functionality. If you are interested in contributing, please read the Contributing Guide.
Example
This shows an example with a Method that at the time of writing is not yet implemented.
INFO
The method used in this example might be implemented down the road. Since most of our effort goes into developing the production code, the documentation might become out of date. This doesn't diminish this example, just the output might be different.
If you want to contribute a better example to the documentation, feel free to open a Pull Request changing this.
Plugin Class
java
package org.mockbukkit.docsdemo;
import org.bukkit.plugin.java.JavaPlugin;
public class DemoPlugin extends JavaPlugin {
@Override
public void onEnable() {
getLogger().info("DemoPlugin enabled");
}
@Override
public void onDisable() {
getLogger().info("Plugin disabled");
}
}kotlin
package org.mockbukkit.docsdemo
import org.bukkit.plugin.java.JavaPlugin
open class DemoPlugin: JavaPlugin() {
override fun onEnable() {
logger.info("${this.name} enabled")
}
override fun onDisable() {
logger.info("${this.name} disabled")
}
}Test Class
java
package org.mockbukkit.docsdemo;
import org.mockbukkit.mockbukkit.MockBukkit;
import org.mockbukkit.mockbukkit.ServerMock;
import org.bukkit.Location;
import org.bukkit.World;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
class DemoPluginTest {
World world;
@BeforeEach
void setUp() {
ServerMock mock = MockBukkit.mock();
DemoPlugin plugin = MockBukkit.load(DemoPlugin.class);
this.world = mock.addSimpleWorld("test");
}
@AfterEach
void tearDown() {
MockBukkit.unmock();
}
@Test
void test() {
world.createExplosion(new Location(world, 0, 0, 0), 0.2f);
}
}kotlin
package org.mockbukkit.docsdemo
import org.mockbukkit.mockbukkit.MockBukkit
import org.mockbukkit.mockbukkit.ServerMock
import org.bukkit.Location
import org.bukkit.World
import org.junit.jupiter.api.AfterEach
import org.junit.jupiter.api.BeforeEach
import org.junit.jupiter.api.Test
import kotlin.jvm.java
class DemoPluginTest {
private lateinit var world: World
@BeforeEach
fun setUp() {
val mock: ServerMock = MockBukkit.mock()
val plugin = MockBukkit.load(DemoPlugin::class.java)
world = mock.addSimpleWorld("test")
}
@AfterEach
fun tearDown() {
MockBukkit.unmock()
}
@Test
fun test() {
world.createExplosion(Location(world, 0.0, 0.0, 0.0), 0.2f)
}
}Executing the code
Executing the test with Gradle, the task will still succeed, since there are only skipped tests.
bash
./gradlew testOutput
bash
BUILD SUCCESSFUL in 522ms
4 actionable tasks: 4 up-to-dateWith JUnit's assertThrow() assertion, we can still get the actual error
Exception
stacktrace
Not implemented
org.mockbukkit.mockbukkit.UnimplementedOperationException: Not implemented
at app//org.mockbukkit.mockbukkit.WorldMock.createExplosion(WorldMock.java:1928)
at app//org.mockbukkit.docsdemo.DemoPluginTest.lambda$test$0(DemoPluginTest.java:32)
at app//org.junit.jupiter.api.AssertThrows.assertThrows(AssertThrows.java:53)
at app//org.junit.jupiter.api.AssertThrows.assertThrows(AssertThrows.java:35)
at app//org.junit.jupiter.api.Assertions.assertThrows(Assertions.java:3128)
at app//org.mockbukkit.docsdemo.DemoPluginTest.test(DemoPluginTest.java:32)
at java.base@21.0.4/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base@21.0.4/java.lang.reflect.Method.invoke(Method.java:580)
at app//org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:766)
at app//org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
at app//org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
at app//org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:156)
at app//org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:147)
at app//org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:86)
at app//org.junit.jupiter.engine.execution.InterceptingExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(InterceptingExecutableInvoker.java:103)
at app//org.junit.jupiter.engine.execution.InterceptingExecutableInvoker.lambda$invoke$0(InterceptingExecutableInvoker.java:93)
at app//org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:106)
at app//org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64)
at app//org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45)
at app//org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37)
at app//org.junit.jupiter.engine.execution.InterceptingExecutableInvoker.invoke(InterceptingExecutableInvoker.java:92)
at app//org.junit.jupiter.engine.execution.InterceptingExecutableInvoker.invoke(InterceptingExecutableInvoker.java:86)
at app//org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$8(TestMethodTestDescriptor.java:217)
at app//org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at app//org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:213)
at app//org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:138)
at app//org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:68)
at app//org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:156)
at app//org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at app//org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:146)
at app//org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at app//org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:144)
at app//org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at app//org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:143)
at app//org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:100)
at java.base@21.0.4/java.util.ArrayList.forEach(ArrayList.java:1596)
at app//org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
at app//org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:160)
at app//org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at app//org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:146)
at app//org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at app//org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:144)
at app//org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at app//org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:143)
at app//org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:100)
at java.base@21.0.4/java.util.ArrayList.forEach(ArrayList.java:1596)
at app//org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
at app//org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:160)
at app//org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at app//org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:146)
at app//org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at app//org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:144)
at app//org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at app//org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:143)
at app//org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:100)
at app//org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:35)
at app//org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
at app//org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:54)
at app//org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:107)
at app//org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:88)
at app//org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute$0(EngineExecutionOrchestrator.java:54)
at app//org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:67)
at app//org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:52)
at app//org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:114)
at app//org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:86)
at app//org.junit.platform.launcher.core.DefaultLauncherSession$DelegatingLauncher.execute(DefaultLauncherSession.java:86)
at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor$CollectAllTestClassesExecutor.processAllTestClasses(JUnitPlatformTestClassProcessor.java:124)
at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor$CollectAllTestClassesExecutor.access$000(JUnitPlatformTestClassProcessor.java:99)
at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor.stop(JUnitPlatformTestClassProcessor.java:94)
at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.stop(SuiteTestClassProcessor.java:63)
at java.base@21.0.4/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base@21.0.4/java.lang.reflect.Method.invoke(Method.java:580)
at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
at org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:33)
at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:92)
at jdk.proxy2/jdk.proxy2.$Proxy6.stop(Unknown Source)
at org.gradle.api.internal.tasks.testing.worker.TestWorker$3.run(TestWorker.java:200)
at org.gradle.api.internal.tasks.testing.worker.TestWorker.executeAndMaintainThreadName(TestWorker.java:132)
at org.gradle.api.internal.tasks.testing.worker.TestWorker.execute(TestWorker.java:103)
at org.gradle.api.internal.tasks.testing.worker.TestWorker.execute(TestWorker.java:63)
at org.gradle.process.internal.worker.child.ActionExecutionWorker.execute(ActionExecutionWorker.java:56)
at org.gradle.process.internal.worker.child.SystemApplicationClassLoaderWorker.call(SystemApplicationClassLoaderWorker.java:121)
at org.gradle.process.internal.worker.child.SystemApplicationClassLoaderWorker.call(SystemApplicationClassLoaderWorker.java:71)
at app//worker.org.gradle.process.internal.worker.GradleWorkerMain.run(GradleWorkerMain.java:69)
at app//worker.org.gradle.process.internal.worker.GradleWorkerMain.main(GradleWorkerMain.java:74)