英文:

Intermittently getting ParameterResolutionException for JUnit5 parameterized tests running in parallel

问题 {#heading}

我正在编写参数化测试，其中测试类和方法并行运行。以下是配置。

junit.jupiter.execution.parallel.enabled = true
junit.jupiter.execution.parallel.mode.default = concurrent
junit.jupiter.execution.parallel.mode.classes.default = concurrent
junit.jupiter.execution.parallel.config.dynamic.factor = 2

测试代码段如下 -

import org.junit.jupiter.api.Tag;
import org.junit.jupiter.api.extension.ExtendWith;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.MethodSource;
@ExtendWith(SimpleCallbackListener.class)
public class HelloWorldTest {
private static final Map<String, List<TestData>> testDataMap;
static {
    testDataMap = TestsConfigManager.readTestConfig(&quot;test-data&quot;);
}
private static List&lt;Object[]&gt; data() {
final List&lt;Object[]&gt; testDataList = prepareTestData(testDataMap);
return testDataList;
}
@ParameterizedTest(name = &quot;{index}: {0}&quot;)
@MethodSource(&quot;data&quot;)
@Tag(&quot;regression&quot;)
public void testMethodName(
final String expected,
final String actual
) {
// test code goes here
}

}

SimpleCallbackListener 如下 -

public class SimpleCallbackListener implements BeforeAllCallback, ExtensionContext.Store.CloseableResource {
    /**
     * 防止同一例程中的多个线程的门卫
     */
    private static final Lock LOCK = new ReentrantLock();
    private static boolean started = false;
    private Instant startTime;
@Override
public void beforeAll(final ExtensionContext context) {
    LOCK.lock();
    try {
        if (!started) {
            startTime = Instant.now();
            requireApplicationInitializer();
            // 下面一行在根测试上下文关闭时注册回调钩子
            context.getRoot().getStore(GLOBAL).put(this.getClass().getName(), this);
            started = true;
        }
    } finally {
        LOCK.unlock();
    }
}

}

问题 {#heading-1}

此设置导致以下间歇性异常。

org.junit.jupiter.api.extension.ParameterResolutionException: No ParameterResolver registered for parameter ... in method ...
	at java.base@17.0.7/java.util.concurrent.RecursiveAction.exec(RecursiveAction.java:194)
	at java.base@17.0.7/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:373)
	at java.base@17.0.7/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1182)
	at java.base@17.0.7/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1655)
	at java.base@17.0.7/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1622)
	at java.base@17.0.7/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:165)

查看了以下建议的答案 -

英文:

I am writing parameterized tests, where test classes and methods are running in parallel. Below is the configuration.

junit.jupiter.execution.parallel.enabled = true
junit.jupiter.execution.parallel.mode.default = concurrent
junit.jupiter.execution.parallel.mode.classes.default = concurrent
junit.jupiter.execution.parallel.config.dynamic.factor = 2

The tests snippet is below -

import org.junit.jupiter.api.Tag;
import org.junit.jupiter.api.extension.ExtendWith;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.MethodSource;
@ExtendWith(SimpleCallbackListener.class)
public class HelloWorldTest {
private static final Map&amp;lt;String, List&amp;lt;TestData&amp;gt;&amp;gt; testDataMap;
static {
    testDataMap = TestsConfigManager.readTestConfig(&amp;amp;quot;test-data&amp;amp;quot;);
}
private static List&amp;amp;lt;Object[]&amp;amp;gt; data() {
final List&amp;amp;lt;Object[]&amp;amp;gt; testDataList = prepareTestData(testDataMap);
return testDataList;
}
@ParameterizedTest(name = &amp;amp;quot;{index}: {0}&amp;amp;quot;)
@MethodSource(&amp;amp;quot;data&amp;amp;quot;)
@Tag(&amp;amp;quot;regression&amp;amp;quot;)
public void testMethodName(
final String expected,
final String actual
) {
// test code goes here
}

}

SimpleCallbackListener is as below -

public class SimpleCallbackListener implements BeforeAllCallback, ExtensionContext.Store.CloseableResource {
    /**
     * gatekeeper to prevent multiple Threads within the same routine
     */
    private static final Lock LOCK = new ReentrantLock();
    private static boolean started = false;
    private Instant startTime;
@Override
public void beforeAll(final ExtensionContext context) {
    LOCK.lock();
    try {
        if (!started) {
            startTime = Instant.now();
            requireApplicationInitializer();
            // The following line registers a callback hook when the root test context is shut down
            context.getRoot().getStore(GLOBAL).put(this.getClass().getName(), this);
            started = true;
        }
    } finally {
        LOCK.unlock();
    }
}

}

Question {#question}

This setup is causing below intermittent exception.

org.junit.jupiter.api.extension.ParameterResolutionException: No ParameterResolver registered for parameter ... in method ...
	at java.base@17.0.7/java.util.concurrent.RecursiveAction.exec(RecursiveAction.java:194)
	at java.base@17.0.7/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:373)
	at java.base@17.0.7/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1182)
	at java.base@17.0.7/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1655)
	at java.base@17.0.7/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1622)
	at java.base@17.0.7/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:165)

Looked at answers suggested at -

答案1 {#1}

得分: 0

我成功找出了根本原因。

问题出在以下方法上。

public static List<Object[]> prepareTestData() {
    final List<Object[]> testDataList = new ArrayList<>();
testDataMap
    .entrySet()
    .parallelStream()
    .forEach(entry -&gt; {
        final String storeAlias = entry.getKey();
        final List&lt;TestData&gt; testDataList = entry.getValue();
        final List&lt;Object[]&gt; list = testDataList
                .stream()
                ...
                .map(testData -&gt; new Object[]{someObj1, someObj2})
                .toList();
        testDataList.addAll(list);
    });

}

在这里，我试图并发地将元素添加到 ArrayList 中。
但后来我意识到 ArrayList 不是线程安全的，因此这导致了问题。

解决方案？ {#heading-2}

我使用了 CopyOnWriteArrayList。英文:

I was able to figure out the root cause.

The issue was with the following method.

public static List&lt;Object[]&gt; prepareTestData() {
    final List&lt;Object[]&gt; testDataList = new ArrayList&lt;&gt;();
testDataMap
	.entrySet()
	.parallelStream()
	.forEach(entry -&amp;amp;gt; {
		final String storeAlias = entry.getKey();
		final List&amp;amp;lt;TestData&amp;amp;gt; testDataList = entry.getValue();
		final List&amp;amp;lt;Object[]&amp;amp;gt; list = testDataList
				.stream()
				...
				.map(testData -&amp;amp;gt; new Object[]{someObj1, someObj2})
				.toList();
		testDataList.addAll(list);
	});

}

Here, I was trying to add the elements to an ArrayList concurrently.
But, then I realized that ArrayList is not thread-safe, and hence this was causing issues.