From 1d202a7311bc6cdca92356c70f64b857b641956a Mon Sep 17 00:00:00 2001
From: InsanusMokrassar <ovsyannikov.alexey95@gmail.com>
Date: Mon, 13 Jan 2020 10:15:01 +0600
Subject: [PATCH] asFlow extension

---
 CHANGELOG.md                                  |  2 ++
 build.gradle                                  |  1 +
 .../krontab/utils/SchedulerFlow.kt            | 25 ++++++++++++++
 .../insanusmokrassar/krontab/utils/RunTest.kt |  8 +++++
 .../krontab/utils/SchedulerFlow.kt            | 34 +++++++++++++++++++
 .../insanusmokrassar/krontab/utils/RunTest.kt |  5 +++
 .../insanusmokrassar/krontab/utils/RunTest.kt |  9 +++++
 7 files changed, 84 insertions(+)
 create mode 100644 src/commonMain/kotlin/com/insanusmokrassar/krontab/utils/SchedulerFlow.kt
 create mode 100644 src/commonTest/kotlin/com/insanusmokrassar/krontab/utils/RunTest.kt
 create mode 100644 src/commonTest/kotlin/com/insanusmokrassar/krontab/utils/SchedulerFlow.kt
 create mode 100644 src/jsTest/kotlin/com/insanusmokrassar/krontab/utils/RunTest.kt
 create mode 100644 src/jvmTest/kotlin/com/insanusmokrassar/krontab/utils/RunTest.kt

diff --git a/CHANGELOG.md b/CHANGELOG.md
index fe02d12..8dc3acf 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,3 +8,5 @@
     * Klock `1.7.3` -> `1.8.6`
 
 ## 0.2.1
+
+* Added support of flows: now any `KronScheduler` can be convert to `Flow<DateTime>` using `asFlow` extension
diff --git a/build.gradle b/build.gradle
index 42e081f..1edeb16 100644
--- a/build.gradle
+++ b/build.gradle
@@ -47,6 +47,7 @@ kotlin {
                 implementation kotlin('test-common')
                 implementation kotlin('test-annotations-common')
                 implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$kotlin_coroutines_version"
+                implementation "org.jetbrains.kotlinx:kotlinx-coroutines-test:$kotlin_coroutines_version"
             }
         }
         jvmMain {
diff --git a/src/commonMain/kotlin/com/insanusmokrassar/krontab/utils/SchedulerFlow.kt b/src/commonMain/kotlin/com/insanusmokrassar/krontab/utils/SchedulerFlow.kt
new file mode 100644
index 0000000..bf0c0f8
--- /dev/null
+++ b/src/commonMain/kotlin/com/insanusmokrassar/krontab/utils/SchedulerFlow.kt
@@ -0,0 +1,25 @@
+package com.insanusmokrassar.krontab.utils
+
+import com.insanusmokrassar.krontab.KronScheduler
+import com.soywiz.klock.DateTime
+import kotlinx.coroutines.*
+import kotlinx.coroutines.flow.*
+
+@FlowPreview
+fun KronScheduler.asFlow(): Flow<DateTime> = SchedulerFlow(this)
+
+@FlowPreview
+class SchedulerFlow(
+    private val scheduler: KronScheduler
+) : AbstractFlow<DateTime>() {
+    @FlowPreview
+    override suspend fun collectSafely(collector: FlowCollector<DateTime>) {
+        while (true) {
+            val now = DateTime.now()
+            val nextTime = scheduler.next(now)
+            val sleepDelay = (nextTime - now).millisecondsLong
+            delay(sleepDelay)
+            collector.emit(nextTime)
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/commonTest/kotlin/com/insanusmokrassar/krontab/utils/RunTest.kt b/src/commonTest/kotlin/com/insanusmokrassar/krontab/utils/RunTest.kt
new file mode 100644
index 0000000..129a4b5
--- /dev/null
+++ b/src/commonTest/kotlin/com/insanusmokrassar/krontab/utils/RunTest.kt
@@ -0,0 +1,8 @@
+package com.insanusmokrassar.krontab.utils
+
+import kotlinx.coroutines.CoroutineScope
+
+/**
+ * Workaround to use suspending functions in unit tests
+ */
+expect fun runTest(block: suspend (scope : CoroutineScope) -> Unit)
diff --git a/src/commonTest/kotlin/com/insanusmokrassar/krontab/utils/SchedulerFlow.kt b/src/commonTest/kotlin/com/insanusmokrassar/krontab/utils/SchedulerFlow.kt
new file mode 100644
index 0000000..29eca3b
--- /dev/null
+++ b/src/commonTest/kotlin/com/insanusmokrassar/krontab/utils/SchedulerFlow.kt
@@ -0,0 +1,34 @@
+package com.insanusmokrassar.krontab.utils
+
+import com.insanusmokrassar.krontab.builder.buildSchedule
+import kotlinx.coroutines.*
+import kotlinx.coroutines.flow.collect
+import kotlinx.coroutines.flow.takeWhile
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+@ExperimentalCoroutinesApi
+@FlowPreview
+class SchedulerFlowTests {
+    @Test
+    fun testThatFlowIsCorrectlyWorkEverySecond() {
+        val kronScheduler = buildSchedule {
+            seconds {
+                0 every 1
+            }
+        }
+
+        val flow = kronScheduler.asFlow()
+
+        runTest {
+            val mustBeCollected = 10
+            var collected = 0
+            flow.takeWhile {
+                collected < mustBeCollected
+            }.collect {
+                collected++
+            }
+            assertEquals(mustBeCollected, collected)
+        }
+    }
+}
diff --git a/src/jsTest/kotlin/com/insanusmokrassar/krontab/utils/RunTest.kt b/src/jsTest/kotlin/com/insanusmokrassar/krontab/utils/RunTest.kt
new file mode 100644
index 0000000..5d87632
--- /dev/null
+++ b/src/jsTest/kotlin/com/insanusmokrassar/krontab/utils/RunTest.kt
@@ -0,0 +1,5 @@
+package com.insanusmokrassar.krontab.utils
+
+import kotlinx.coroutines.*
+
+actual fun runTest(block: suspend (scope : CoroutineScope) -> Unit): dynamic = GlobalScope.promise { block(this) }
diff --git a/src/jvmTest/kotlin/com/insanusmokrassar/krontab/utils/RunTest.kt b/src/jvmTest/kotlin/com/insanusmokrassar/krontab/utils/RunTest.kt
new file mode 100644
index 0000000..a20cefc
--- /dev/null
+++ b/src/jvmTest/kotlin/com/insanusmokrassar/krontab/utils/RunTest.kt
@@ -0,0 +1,9 @@
+package com.insanusmokrassar.krontab.utils
+
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.runBlocking
+
+/**
+ * Workaround to use suspending functions in unit tests
+ */
+actual fun runTest(block: suspend (scope: CoroutineScope) -> Unit) = runBlocking(block = block)