Issue#67 Extract runOnUIAwaitOnCurrent into separate module

test-util-android/.gitignore

@@ -0,0 +1 @@
+/build

test-util-android/build.gradle

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+plugins {
+    id 'com.android.library'
+    id 'org.jetbrains.kotlin.android'
+}
+
+android {
+    compileSdk 31
+
+    defaultConfig {
+        minSdk 21
+        targetSdk 31
+
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+        consumerProguardFiles "consumer-rules.pro"
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+        }
+    }
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
+    kotlinOptions {
+        jvmTarget = '1.8'
+    }
+}
+
+dependencies {
+    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-test:$coroutines_version"
+}

test-util-android/proguard-rules.pro

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+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile

test-util-android/src/main/AndroidManifest.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="org.fnives.test.showcase.android.testutil">
+
+</manifest>

test-util-android/src/main/java/org/fnives/test/showcase/android/testutil/synchronization/doBlockinglyOnMainThread.kt

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+package org.fnives.test.showcase.android.testutil.synchronization
+
+import android.os.Handler
+import android.os.Looper
+import kotlinx.coroutines.CompletableDeferred
+import kotlinx.coroutines.runBlocking
+
+/**
+ * Runs the given action on the MainThread and blocks currentThread, until it is completed.
+ *
+ * It is safe to call this from the MainThread.
+ */
+fun runOnUIAwaitOnCurrent(action: () -> Unit) {
+    if (Looper.myLooper() === Looper.getMainLooper()) {
+        action()
+    } else {
+        val deferred = CompletableDeferred<Unit>()
+        Handler(Looper.getMainLooper()).post {
+            action()
+            deferred.complete(Unit)
+        }
+        runBlocking { deferred.await() }
+    }
+}