ToStringTest.kt

package kotlinx.coroutines.debug

import kotlinx.coroutines.testing.*
import kotlinx.coroutines.*
import kotlinx.coroutines.channels.*
import org.junit.*
import org.junit.Test
import java.io.*
import kotlin.coroutines.*
import kotlin.test.*

class ToStringTest : DebugTestBase() {

    private suspend fun CoroutineScope.launchNestedScopes(): Job {
        return launch {
            expect(1)
            coroutineScope {
                expect(2)
                launchDelayed()

                supervisorScope {
                    expect(3)
                    launchDelayed()
                }
            }
        }
    }

    private fun CoroutineScope.launchDelayed(): Job {
        return launch {
            delay(Long.MAX_VALUE)
        }
    }

    @Test
    fun testPrintHierarchyWithScopes() = runBlocking {
        val tab = '\t'
        val expectedString = """
          "coroutine":StandaloneCoroutine{Active}, continuation is SUSPENDED at line ToStringTest${'$'}launchNestedScopes$2$1.invokeSuspend(ToStringTest.kt)
          $tab"coroutine":StandaloneCoroutine{Active}, continuation is SUSPENDED at line ToStringTest${'$'}launchDelayed$1.invokeSuspend(ToStringTest.kt)
          $tab"coroutine":StandaloneCoroutine{Active}, continuation is SUSPENDED at line ToStringTest${'$'}launchDelayed$1.invokeSuspend(ToStringTest.kt)
            """.trimIndent()

        val job = launchNestedScopes()
        try {
            repeat(5) { yield() }
            val expected = expectedString.trimStackTrace().trimPackage()
            expect(4)
            assertEquals(expected, DebugProbes.jobToString(job).trimEnd().trimStackTrace().trimPackage())
            assertEquals(expected, DebugProbes.scopeToString(CoroutineScope(job)).trimEnd().trimStackTrace().trimPackage())
        } finally {
            finish(5)
            job.cancelAndJoin()
        }
    }

    @Test
    fun testCompletingHierarchy() = runBlocking {
        val tab = '\t'
        val expectedString = """
            "coroutine#2":StandaloneCoroutine{Completing}
            $tab"foo#3":DeferredCoroutine{Active}, continuation is SUSPENDED at line ToStringTest${'$'}launchHierarchy${'$'}1${'$'}1.invokeSuspend(ToStringTest.kt:30)
            $tab"coroutine#4":ActorCoroutine{Active}, continuation is SUSPENDED at line ToStringTest${'$'}launchHierarchy${'$'}1${'$'}2${'$'}1.invokeSuspend(ToStringTest.kt:40)
            $tab$tab"coroutine#5":StandaloneCoroutine{Active}, continuation is SUSPENDED at line ToStringTest${'$'}launchHierarchy${'$'}1${'$'}2${'$'}job$1.invokeSuspend(ToStringTest.kt:37)
            """.trimIndent()

        checkHierarchy(isCompleting = true, expectedString = expectedString)
    }

    @Test
    fun testActiveHierarchy() = runBlocking {
        val tab = '\t'
        val expectedString = """
            "coroutine#2":StandaloneCoroutine{Active}, continuation is SUSPENDED at line ToStringTest${'$'}launchHierarchy${'$'}1.invokeSuspend(ToStringTest.kt:94)
            $tab"foo#3":DeferredCoroutine{Active}, continuation is SUSPENDED at line ToStringTest${'$'}launchHierarchy${'$'}1${'$'}1.invokeSuspend(ToStringTest.kt:30)
            $tab"coroutine#4":ActorCoroutine{Active}, continuation is SUSPENDED at line ToStringTest${'$'}launchHierarchy${'$'}1${'$'}2${'$'}1.invokeSuspend(ToStringTest.kt:40)
            $tab$tab"coroutine#5":StandaloneCoroutine{Active}, continuation is SUSPENDED at line ToStringTest${'$'}launchHierarchy${'$'}1${'$'}2${'$'}job$1.invokeSuspend(ToStringTest.kt:37)
            """.trimIndent()
        checkHierarchy(isCompleting = false, expectedString = expectedString)
    }

    private suspend fun CoroutineScope.checkHierarchy(isCompleting: Boolean, expectedString: String) {
        val root = launchHierarchy(isCompleting)
        repeat(4) { yield() }
        val expected = expectedString.trimStackTrace().trimPackage()
        expect(6)
        assertEquals(expected, DebugProbes.jobToString(root).trimEnd().trimStackTrace().trimPackage())
        assertEquals(expected, DebugProbes.scopeToString(CoroutineScope(root)).trimEnd().trimStackTrace().trimPackage())
        assertEquals(expected, printToString { DebugProbes.printScope(CoroutineScope(root), it) }.trimEnd().trimStackTrace().trimPackage())
        assertEquals(expected, printToString { DebugProbes.printJob(root, it) }.trimEnd().trimStackTrace().trimPackage())

        root.cancelAndJoin()
        finish(7)
    }

    private fun CoroutineScope.launchHierarchy(isCompleting: Boolean): Job {
        return launch {
            expect(1)
            async(CoroutineName("foo")) {
                expect(2)
                delay(Long.MAX_VALUE)
            }

            actor<Int> {
                expect(3)
                val job = launch {
                    expect(4)
                    delay(Long.MAX_VALUE)
                }

                withContext(wrapperDispatcher(coroutineContext)) {
                    expect(5)
                    job.join()
                }
            }

            if (!isCompleting) {
                delay(Long.MAX_VALUE)
            }
        }
    }

    private fun wrapperDispatcher(context: CoroutineContext): CoroutineContext {
        val dispatcher = context[ContinuationInterceptor] as CoroutineDispatcher
        return object : CoroutineDispatcher() {
            override fun dispatch(context: CoroutineContext, block: Runnable) {
                dispatcher.dispatch(context, block)
            }
        }
    }

    private inline fun printToString(block: (PrintStream) -> Unit): String {
        val baos = ByteArrayOutputStream()
        val ps = PrintStream(baos)
        block(ps)
        ps.close()
        return baos.toString()
    }
}