add websockets work

ktor/tests/build.gradle

@@ -0,0 +1,39 @@
+buildscript {
+    repositories {
+        mavenLocal()
+        jcenter()
+        mavenCentral()
+    }
+
+    dependencies {
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+        classpath "org.jetbrains.kotlin:kotlin-serialization:$kotlin_version"
+    }
+}
+
+plugins {
+    id "org.jetbrains.kotlin.plugin.serialization" version "$kotlin_version"
+}
+
+project.version = "$core_version"
+project.group = "com.insanusmokrassar"
+
+apply plugin: "java-library"
+apply plugin: "kotlin"
+
+repositories {
+    mavenLocal()
+    jcenter()
+    mavenCentral()
+    maven { url "https://kotlin.bintray.com/kotlinx" }
+}
+
+dependencies {
+    implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
+
+    api projectByName("postssystem.ktor.client")
+    api projectByName("postssystem.ktor.server")
+
+    testImplementation "org.jetbrains.kotlin:kotlin-test"
+    testImplementation "org.jetbrains.kotlin:kotlin-test-junit"
+}

ktor/tests/src/test/kotlin/com/insanusmokrassar/postssystem/ktor/tests/TestsScope.kt

@@ -0,0 +1,6 @@
+package com.insanusmokrassar.postssystem.ktor.tests
+
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+
+val testsScope = CoroutineScope(Dispatchers.Default)

ktor/tests/src/test/kotlin/com/insanusmokrassar/postssystem/ktor/tests/WebsocketsTest.kt

@@ -0,0 +1,72 @@
+package com.insanusmokrassar.postssystem.ktor.tests
+
+import com.insanusmokrassar.postssystem.ktor.client.createStandardWebsocketFlow
+import com.insanusmokrassar.postssystem.ktor.server.createKtorServer
+import com.insanusmokrassar.postssystem.ktor.server.includeWebsocketHandling
+import com.insanusmokrassar.postssystem.ktor.standardKtorSerializer
+import io.ktor.application.install
+import io.ktor.application.log
+import io.ktor.client.HttpClient
+import io.ktor.http.cio.websocket.pingPeriod
+import io.ktor.http.cio.websocket.timeout
+import io.ktor.routing.route
+import io.ktor.routing.routing
+import io.ktor.websocket.WebSockets
+import kotlinx.coroutines.*
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.flow.*
+import kotlinx.serialization.builtins.serializer
+import org.junit.Test
+import java.time.Duration
+import kotlin.test.assertEquals
+import kotlin.test.assertNull
+
+class WebsocketsTest {
+    @Test
+    fun testCommonWebsocketFunctionality() {
+        val port = 60000
+        val suburl = "test"
+        val dataFlowChannel = Channel<Int>(Channel.UNLIMITED)
+        val dataFlow = dataFlowChannel.consumeAsFlow()
+        val serverUrl = "127.0.0.1:$port"
+        val server = createKtorServer(host = "127.0.0.1", port = port) {
+            install(WebSockets)
+            routing {
+                includeWebsocketHandling(suburl, dataFlow) {
+                    standardKtorSerializer.dump(Int.serializer(), it)
+                }
+            }
+        }.also {
+            it.start(false)
+        }
+        runBlocking {
+            delay(100L)
+        }
+        val client = HttpClient {
+            install(io.ktor.client.features.websocket.WebSockets)
+        }
+        val incomingWebsocketFlow = createStandardWebsocketFlow(
+            client,
+            "$serverUrl/$suburl"
+        ) {
+            standardKtorSerializer.load(Int.serializer(), it)
+        }
+
+        var currentlyCheckingData: Int? = null
+        incomingWebsocketFlow.onEach {
+            assertEquals(currentlyCheckingData, it)
+            currentlyCheckingData = null
+        }.launchIn(CoroutineScope(testsScope.coroutineContext + SupervisorJob()))
+        runBlocking {
+            (0 until 100).asFlow().collect {
+                currentlyCheckingData = it
+                dataFlowChannel.send(it)
+                while (currentlyCheckingData != null) {
+                    delay(10L)
+                }
+                assertNull(currentlyCheckingData)
+            }
+        }
+        server.stop(1000L, 1000L)
+    }
+}