[BUG] Playwright clashes with jacoco (Java Code Coverage)

Context:

• Playwright Version: 1.18
• Operating System: Linux
• Browser: Chromium

Describe the bug

The newest version seems to clash with jacoco which is a popular java code coverage tool. Jacoco (as all code coverage tools usually do) instruments the java bytecode with code coverage tracking instructions. Playwright internals does not seem to like that anymore. See the stacktrace.

We upgraded Playwright from 1.14.1, in which everything worked, to 1.18.0, which now fails. I don’t know in which exact version the problem was introduced.

Note that using the code coverage tracker in our specific case is probably a mistake (we don’t need code coverage for our playwright tests), but because jacoco is extremely popular, any library should make sure that it works correctly with it.

Stacktrace

com.microsoft.playwright.PlaywrightException: Internal error
	at app//com.microsoft.playwright.impl.Utils.convertType(Utils.java:69)
	at app//com.microsoft.playwright.impl.LocatorImpl.innerText(LocatorImpl.java:210)
	at app//com.microsoft.playwright.Locator.innerText(Locator.java:2079)
	at <... redacted client code ...>
	at java.base@11.0.13/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base@11.0.13/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base@11.0.13/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base@11.0.13/java.lang.reflect.Method.invoke(Method.java:566)
	at app//org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)
	at app//org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at app//org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56)
	at app//org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at app//org.junit.rules.TestWatcher$1.evaluate(TestWatcher.java:61)
	at app//org.junit.rules.TestWatcher$1.evaluate(TestWatcher.java:61)
	at app//org.junit.rules.ExternalResource$1.evaluate(ExternalResource.java:54)
	at app//org.junit.rules.RunRules.evaluate(RunRules.java:20)
	at app//org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
	at app//org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100)
	at app//org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366)
	at app//org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103)
	at app//org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63)
	at app//org.junit.runners.ParentRunner$4.run(ParentRunner.java:331)
	at app//org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:79)
	at app//org.junit.runners.ParentRunner.runChildren(ParentRunner.java:329)
	at app//org.junit.runners.ParentRunner.access$100(ParentRunner.java:66)
	at app//org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:293)
	at app//org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
	at app//org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
	at app//org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
	at app//org.junit.runners.ParentRunner.run(ParentRunner.java:413)
	at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.runTestClass(JUnitTestClassExecutor.java:110)
	at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.execute(JUnitTestClassExecutor.java:58)
	at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.execute(JUnitTestClassExecutor.java:38)
	at org.gradle.api.internal.tasks.testing.junit.AbstractJUnitTestClassProcessor.processTestClass(AbstractJUnitTestClassProcessor.java:62)
	at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.processTestClass(SuiteTestClassProcessor.java:51)
	at java.base@11.0.13/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base@11.0.13/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base@11.0.13/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base@11.0.13/java.lang.reflect.Method.invoke(Method.java:566)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
	at org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:33)
	at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:94)
	at com.sun.proxy.$Proxy5.processTestClass(Unknown Source)
	at org.gradle.api.internal.tasks.testing.worker.TestWorker$2.run(TestWorker.java:176)
	at org.gradle.api.internal.tasks.testing.worker.TestWorker.executeAndMaintainThreadName(TestWorker.java:129)
	at org.gradle.api.internal.tasks.testing.worker.TestWorker.execute(TestWorker.java:100)
	at org.gradle.api.internal.tasks.testing.worker.TestWorker.execute(TestWorker.java:60)
	at org.gradle.process.internal.worker.child.ActionExecutionWorker.execute(ActionExecutionWorker.java:56)
	at org.gradle.process.internal.worker.child.SystemApplicationClassLoaderWorker.call(SystemApplicationClassLoaderWorker.java:133)
	at org.gradle.process.internal.worker.child.SystemApplicationClassLoaderWorker.call(SystemApplicationClassLoaderWorker.java:71)
	at app//worker.org.gradle.process.internal.worker.GradleWorkerMain.run(GradleWorkerMain.java:69)
	at app//worker.org.gradle.process.internal.worker.GradleWorkerMain.main(GradleWorkerMain.java:74)
Caused by: java.lang.RuntimeException: Unexpected field modifiers: com.microsoft.playwright.Frame.InnerTextOptions.$jacocoData, modifiers: 4234
	at com.microsoft.playwright.impl.Utils.convertType(Utils.java:55)
	... 54 more

[jhyot]

@yury-s Tested with 1.19.0 release version, it is working.

[jhyot]

There is a FAQ from jacoco about this problem: https://www.eclemma.org/jacoco/trunk/doc/faq.html

My code uses reflection. Why does it fail when I execute it with JaCoCo?

To collect execution data JaCoCo instruments the classes under test which adds two members to the classes: A private static field $jacocoData and a private static method $jacocoInit(). Both members are marked as synthetic. Please change your code to ignore synthetic members. This is a good practice anyways as also the Java compiler creates synthetic members in certain situation.

The synthetic fields in question can be checked with isSynthetic().