Random au.com.dius.pact.core.support.json.JsonException when running tasks in parallel

[bkosawa]

When running the task in the CI, we are experiencing random JsonException such as the following

au.com.dius.pact.core.support.json.JsonException: au.com.dius.pact.core.support.json.JsonException: Invalid JSON (37:2), found unexpected character 'a'
au.com.dius.pact.core.support.json.JsonException: Invalid JSON (37:2), found unexpected character 'a'
	at app//au.com.dius.pact.core.support.json.JsonLexer.unexpectedCharacter(JsonParser.kt:88)
	at app//au.com.dius.pact.core.support.json.JsonLexer.nextToken(JsonParser.kt:79)
	at app//au.com.dius.pact.core.support.json.JsonParser.nextTokenOrThrow(JsonParser.kt:279)
	at app//au.com.dius.pact.core.support.json.JsonParser.parse(JsonParser.kt:170)
	at app//au.com.dius.pact.core.support.json.JsonParser.parseString(JsonParser.kt:131)
	at app//au.com.dius.pact.core.model.DefaultPactWriter.writePact(PactWriter.kt:94)
	at app//au.com.dius.pact.consumer.BaseMockServer.verifyResultAndWritePact(MockHttpServer.kt:167)
	at app//au.com.dius.pact.consumer.BaseMockServer.runAndWritePact(MockHttpServer.kt:148)
	at app//au.com.dius.pact.consumer.ConsumerPactRunnerKt.runConsumerTest(ConsumerPactRunner.kt:32)
	at app//au.com.dius.pact.consumer.junit.ConsumerPactTest.testPact(ConsumerPactTest.java:33)
	at [email protected]/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at [email protected]/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at [email protected]/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at [email protected]/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.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.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
	at app//org.junit.runners.ParentRunner.run(ParentRunner.java:413)
	at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.runTestClass(JUnitTestClassExecutor.java:110)
	at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.execute(JUnitTestClassExecutor.java:58)
	at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.execute(JUnitTestClassExecutor.java:38)
	at org.gradle.api.internal.tasks.testing.junit.AbstractJUnitTestClassProcessor.processTestClass(AbstractJUnitTestClassProcessor.java:62)
	at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.processTestClass(SuiteTestClassProcessor.java:51)
	at [email protected]/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at [email protected]/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at [email protected]/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at [email protected]/java.lang.reflect.Method.invoke(Method.java:566)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
	at org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:33)
	at org.gradle.internal.dispatch.ProxyDispatchAdapter$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)

It seems to be similar to https://github.com/pact-foundation/pact-jvm/issues/475 older issue

[bkosawa]

We are using the following version:

[versions]
pact-jvm = '4.3.6'

[libraries]
# Contract Test
pact-jvm-consumer = { group = "au.com.dius.pact", name = "consumer", version.ref = "pact-jvm" }
pact-jvm-consumer-junit = { group = "au.com.dius.pact.consumer", name = "junit", version.ref = "pact-jvm" }
apachecommons-configuration = { group = "org.apache.commons", name = "commons-configuration2", version = "2.7" }

[bkosawa]

It seems to be a synchronization issue bc sometimes it fails 2 different tests with completely different bodies and the same unexpected character.