Kotlin test generation doesn't work

[sofurihafe]

Description

When trying to generate tests in Kotlin project on the current main branch, no tests are generated.

To Reproduce

Generate a test for any method (as for the example you can use the following method):

class SimpleClass {
    fun min(a: Int, b: Int): Int {
        return if (a < b) a else b
    }
}

Expected behavior

Successfully generated tests.

Actual behavior

IDE error occurs and no tests are generated.

Visual proofs (screenshots, logs, images)

com.jetbrains.rd.util.reactive.RdFault: private fun computeSourc…     sourceFile
        } must not be null, reason: java.lang.NullPointerException: private fun computeSourc…     sourceFile
        } must not be null
	at org.utbot.intellij.plugin.process.EngineProcess.computeSourceFileByClass(EngineProcess.kt:170)
	at org.utbot.intellij.plugin.process.EngineProcess.access$computeSourceFileByClass(EngineProcess.kt:62)
	at org.utbot.intellij.plugin.process.EngineProcess$createTestGenerator$1.invoke(EngineProcess.kt:187)
	at org.utbot.intellij.plugin.process.EngineProcess$createTestGenerator$1.invoke(EngineProcess.kt:187)
	at com.jetbrains.rd.framework.IRdEndpoint$set$1.invoke(TaskInterfaces.kt:182)
	at com.jetbrains.rd.framework.IRdEndpoint$set$1.invoke(TaskInterfaces.kt:182)
	at com.jetbrains.rd.framework.impl.RdCall.onWireReceived(RdTask.kt:362)
	at com.jetbrains.rd.framework.MessageBroker$invoke$2$2.invoke(MessageBroker.kt:57)
	at com.jetbrains.rd.framework.MessageBroker$invoke$2$2.invoke(MessageBroker.kt:56)
	at com.jetbrains.rd.framework.impl.ProtocolContexts.readMessageContextAndInvoke(ProtocolContexts.kt:148)
	at com.jetbrains.rd.framework.MessageBroker$invoke$2.invoke(MessageBroker.kt:56)
	at com.jetbrains.rd.framework.MessageBroker$invoke$2.invoke(MessageBroker.kt:54)
	at com.jetbrains.rd.util.threading.SingleThreadSchedulerBase.queue$lambda-3(SingleThreadScheduler.kt:41)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
	at java.base/java.lang.Thread.run(Thread.java:833)

	at com.jetbrains.rd.framework.RdTaskResult$Companion.read(TaskInterfaces.kt:30)
	at com.jetbrains.rd.framework.impl.CallSiteWiredRdTask.onWireReceived(RdTask.kt:106)
	at com.jetbrains.rd.framework.MessageBroker$invoke$2$2.invoke(MessageBroker.kt:57)
	at com.jetbrains.rd.framework.MessageBroker$invoke$2$2.invoke(MessageBroker.kt:56)
	at com.jetbrains.rd.framework.impl.ProtocolContexts.readMessageContextAndInvoke(ProtocolContexts.kt:148)
	at com.jetbrains.rd.framework.MessageBroker$invoke$2.invoke(MessageBroker.kt:56)
	at com.jetbrains.rd.framework.MessageBroker$invoke$2.invoke(MessageBroker.kt:54)
	at com.jetbrains.rd.framework.impl.RdCall$createResponseScheduler$1.queue$execute(RdTask.kt:280)
	at com.jetbrains.rd.framework.impl.RdCall$createResponseScheduler$1.access$queue$execute(RdTask.kt:269)
	at com.jetbrains.rd.framework.impl.RdCall$createResponseScheduler$1$queue$1.invokeSuspend(RdTask.kt:289)
	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
	at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
	at kotlinx.coroutines.EventLoopImplBase.processNextEvent(EventLoop.common.kt:284)
	at kotlinx.coroutines.BlockingCoroutine.joinBlocking(Builders.kt:85)
	at kotlinx.coroutines.BuildersKt__BuildersKt.runBlocking(Builders.kt:59)
	at kotlinx.coroutines.BuildersKt.runBlocking(Unknown Source)
	at kotlinx.coroutines.BuildersKt__BuildersKt.runBlocking$default(Builders.kt:38)
	at kotlinx.coroutines.BuildersKt.runBlocking$default(Unknown Source)
	at org.utbot.rd.UtRdUtilKt.startBlocking(UtRdUtil.kt:30)
	at org.utbot.intellij.plugin.process.EngineProcess.generate(EngineProcess.kt:270)
	at org.utbot.intellij.plugin.generator.UtTestsDialogProcessor$createTests$1$1.run(UtTestsDialogProcessor.kt:234)
	at com.intellij.openapi.progress.impl.CoreProgressManager.startTask(CoreProgressManager.java:442)
	at com.intellij.openapi.progress.impl.ProgressManagerImpl.startTask(ProgressManagerImpl.java:114)
	at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$runProcessWithProgressAsynchronously$5(CoreProgressManager.java:493)
	at com.intellij.openapi.progress.impl.ProgressRunner.lambda$submit$3(ProgressRunner.java:252)
	at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$runProcess$2(CoreProgressManager.java:188)
	at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$executeProcessUnderProgress$12(CoreProgressManager.java:608)
	at com.intellij.openapi.progress.impl.CoreProgressManager.registerIndicatorAndRun(CoreProgressManager.java:683)
	at com.intellij.openapi.progress.impl.CoreProgressManager.computeUnderProgress(CoreProgressManager.java:639)
	at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:607)
	at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:60)
	at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:175)
	at com.intellij.openapi.progress.impl.ProgressRunner.lambda$submit$4(ProgressRunner.java:252)
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1768)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
	at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1$1.run(Executors.java:702)
	at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1$1.run(Executors.java:699)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
	at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1.run(Executors.java:699)
	at java.base/java.lang.Thread.run(Thread.java:833)

Environment

Maven and Gradle kt projects.
Output test languages Java and Kotlin.

[alisevych]

Reproducing for a random Kotlin class/file.