CoroutineTests

CoroutineTests.kt

package com.example.coroutine

import io.kotest.core.spec.style.DescribeSpec
import io.kotest.matchers.shouldBe
import kotlinx.coroutines.*
import kotlinx.coroutines.reactive.awaitFirstOrNull
import kotlinx.coroutines.reactor.mono
import org.jooq.DSLContext
import org.jooq.impl.DSL
import kotlin.coroutines.CoroutineContext
import kotlin.coroutines.coroutineContext

data class DslContextCoroutineContext(val dslContext: DSLContext)
    : AbstractCoroutineContextElement(DslContextCoroutineContext) {
    companion object Key : CoroutineContext.Key<DslContextCoroutineContext>
}

/* class DslContextCoroutineContext(val dslContext: DSLContext) : CoroutineDispatcher() { // 혹시?
    override fun isDispatchNeeded(context: CoroutineContext): Boolean = true // 이로 인해 dispatch 불렸지만
    override fun dispatch(context: CoroutineContext, block: Runnable) = Unit // block를 불러주지 않은 경우 hang
    override fun toString(): String = "DslContextCoroutineContext($dslContext)"
} */

suspend fun <T> DSLContext.transactional(block: suspend (DSLContext) -> T?): T? {
    val current: CoroutineContext = coroutineContext.minusKey(Job)

    return transactionPublisher {
        it.dsl().let { tx ->
            mono<T>(current + DslContextCoroutineContext(tx) + Dispatchers.Unconfined) { block(tx) }
        }
    }.awaitFirstOrNull()
}

class CoroutineTests : DescribeSpec({
    describe("coroutine builder") {
        it("should be await value") {
            val ctx = DSL.using("jdbc:h2:~/test;AUTO_SERVER=TRUE", "SA", "")
            val result = ctx.transactional {
                delay(1000)
                "Hello"
            }
            result.shouldBe("Hello")
        }

        it("mono(coroutineContext) should be await value") {
            val result = mono(coroutineContext.minusKey(Job)) { "Hello" }.awaitFirstOrNull()
            result.shouldBe("Hello")
        }

        it("async(coroutineContext) should be await value") {
            val result = async(coroutineContext) { "Hello" }.await()
            result.shouldBe("Hello")
        }

        it("withContext(coroutineContext) should be await value") {
            val result = withContext(coroutineContext) { "Hello" }
            result.shouldBe("Hello")
        }
    }
})