with-test-scope

Code

package com.glassthought.sandbox

import com.glassthought.sandbox.impl.CustomDescribeSpec
import com.glassthought.sandbox.util.out.impl.out
import io.kotest.matchers.shouldBe
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.ExperimentalCoroutinesApi
import kotlinx.coroutines.delay
import kotlinx.coroutines.launch
import kotlinx.coroutines.test.*
import kotlin.time.Duration.Companion.milliseconds
import kotlin.time.Duration.Companion.seconds

@OptIn(ExperimentalCoroutinesApi::class)
fun createTestScope(): TestScope = TestScope()

val sharedTestScope = createTestScope()

/** Shows how to create and pass TestScope instances for virtual time control. */
@OptIn(ExperimentalCoroutinesApi::class)
class VirtualTimeWithTestScopeDescribeSpec : CustomDescribeSpec({


  describe("Timer Service with TestScope instances") {
    out.delay(500.milliseconds, whatFor = "describe setup delay REAL DELAY")

    it("should pass TestScope to multiple services") {
      val testScope = sharedTestScope
      val service1 = BackgroundService("Service-1", testScope)
      val service2 = BackgroundService("Service-2", testScope)

      var completedServices = 0

      // Both services use same TestScope
      service1.doWork {
        completedServices++

        out.info("Service-1 completed")
      }

      service2.doWork {
        completedServices++

        out.info("Service-2 completed")
      }

      out.info("Both services started, time is: ${testScope.testScheduler.currentTime}")

      // Advance time in controlled steps
      testScope.testScheduler.advanceTimeBy(1500.milliseconds)
      testScope.testScheduler.runCurrent()

      completedServices shouldBe 1 // Only Service-1 completed (1 second delay)
      out.info("After 1.5s: $completedServices services completed")

      testScope.testScheduler.advanceTimeBy(1000.milliseconds)
      testScope.testScheduler.runCurrent()

      completedServices shouldBe 2 // Both completed
      out.info("After 2.5s: $completedServices services completed")
    }
  }
})


class BackgroundService(
  private val name: String,
  private val scope: CoroutineScope
) {
  fun doWork(onComplete: suspend () -> Unit) {
    scope.launch {
      val delayTime = if (name == "Service-1") 1.seconds else 2.seconds

      out.delay(delayTime, "background work for $name (VIRTUALIZED DELAY)")
      onComplete()
    }
  }
}

Command to reproduce:

gt.sandbox.checkout.commit ba67502e427790ab7fa7 \
&& cd "${GT_SANDBOX_REPO}" \
&& cmd.run.announce "./gradlew test --rerun-tasks"

Recorded output of command:

Picked up JAVA_TOOL_OPTIONS: -Dkotlinx.coroutines.debug
> Task :app:checkKotlinGradlePluginConfigurationErrors SKIPPED
> Task :app:processResources NO-SOURCE
> Task :app:processTestResources NO-SOURCE
> Task :app:compileKotlin
> Task :app:compileJava NO-SOURCE
> Task :app:classes UP-TO-DATE
> Task :app:compileTestKotlin
> Task :app:compileTestJava NO-SOURCE
> Task :app:testClasses UP-TO-DATE

> Task :app:test
Picked up JAVA_TOOL_OPTIONS: -Dkotlinx.coroutines.debug

Gradle Test Executor 3 STANDARD_OUT
    Warning: Kotest autoscan is enabled. This means Kotest will scan the classpath for extensions that are annotated with @AutoScan. To avoid this startup cost, disable autoscan by setting the system property 'kotest.framework.classpath.scanning.autoscan.disable=true'. In 6.0 this value will default to true. For further details see https://kotest.io/docs/next/framework/project-config.html#runtime-detection

com.glassthought.sandbox.VirtualTimeWithTestScopeDescribeSpec > Timer Service with TestScope instances STANDARD_OUT
    [INFO][elapsed:   10ms][①][coroutname:@coroutine#3]    [🐢] Delaying for [500ms] what_for=[describe setup delay REAL DELAY]
    [INFO][elapsed:  514ms][①][coroutname:@coroutine#3]    Done delaying for [500ms] what_for=[describe setup delay REAL DELAY]

com.glassthought.sandbox.VirtualTimeWithTestScopeDescribeSpec > Timer Service with TestScope instances > should pass TestScope to multiple services STARTED

com.glassthought.sandbox.VirtualTimeWithTestScopeDescribeSpec > Timer Service with TestScope instances > should pass TestScope to multiple services STANDARD_OUT
    [INFO][elapsed:  539ms][①][coroutname:@coroutine#3]       Both services started, time is: 0
    [INFO][elapsed:  539ms][⓶][coroutname:@coroutine#4] [🐢] Delaying for [1s] what_for=[background work for Service-1 (VIRTUALIZED DELAY)]
    [INFO][elapsed:  539ms][⓷][coroutname:@coroutine#5] [🐢] Delaying for [2s] what_for=[background work for Service-2 (VIRTUALIZED DELAY)]
    [INFO][elapsed:  540ms][⓶][coroutname:@coroutine#4] Done delaying for [1s] what_for=[background work for Service-1 (VIRTUALIZED DELAY)]
    [INFO][elapsed:  540ms][⓶][coroutname:@coroutine#4] Service-1 completed
    [INFO][elapsed:  541ms][①][coroutname:@coroutine#3]       After 1.5s: 1 services completed
    [INFO][elapsed:  541ms][⓷][coroutname:@coroutine#5] Done delaying for [2s] what_for=[background work for Service-2 (VIRTUALIZED DELAY)]
    [INFO][elapsed:  541ms][⓷][coroutname:@coroutine#5] Service-2 completed
    [INFO][elapsed:  542ms][①][coroutname:@coroutine#3]       After 2.5s: 2 services completed

com.glassthought.sandbox.VirtualTimeWithTestScopeDescribeSpec > Timer Service with TestScope instances > should pass TestScope to multiple services PASSED

BUILD SUCCESSFUL in 3s
3 actionable tasks: 3 executed