Add simple jvm scripting host test

libraries/scripting/jvm-host/build.gradle.kts

@@ -16,11 +16,13 @@ dependencies {
     compile(project(":kotlin-script-util"))
     compileOnly(project(":compiler:cli"))
     compileOnly(intellijCoreDep())
+    runtime(projectRuntimeJar(":kotlin-compiler"))
+    testCompile(commonDep("junit"))
 }
 
 sourceSets {
     "main" { projectDefault() }
-    "test" {}
+    "test" { projectDefault() }
 }
 
 kotlin.experimental.coroutines = Coroutines.ENABLE

libraries/scripting/jvm-host/test/kotlin/script/experimental/jvmhost/test/ScriptingHostTest.kt

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2010-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package kotlin.script.experimental.jvmhost.test
+
+import org.junit.Assert
+import org.junit.Test
+import java.io.ByteArrayOutputStream
+import java.io.PrintStream
+import kotlin.script.experimental.api.ResultWithDiagnostics
+import kotlin.script.experimental.host.toScriptSource
+import kotlin.script.experimental.jvmhost.BasicJvmScriptingHost
+import kotlin.script.experimental.jvmhost.createCompilationConfigurationFromTemplate
+import kotlin.script.templates.standard.SimpleScriptTemplate
+
+class ScriptingHostTest {
+
+    @Test
+    fun testSimpleUsage() {
+        val greeting = "Hello from script!"
+        val output = captureOut {
+            evalScript("println(\"$greeting\")")
+        }.trim()
+        Assert.assertEquals(greeting, output)
+    }
+}
+
+internal fun evalScript(script: String) {
+    val compilationConfiguration = createCompilationConfigurationFromTemplate<SimpleScriptTemplate>()
+    val res = BasicJvmScriptingHost().eval(script.toScriptSource(), compilationConfiguration, null)
+    if (res is ResultWithDiagnostics.Failure) {
+        throw Exception("Compilation/evaluation failed:\n  ${res.reports.joinToString("\n  ") { it.exception?.toString() ?: it.message }}")
+    }
+}
+
+internal fun captureOut(body: () -> Unit): String {
+    val outStream = ByteArrayOutputStream()
+    val prevOut = System.out
+    System.setOut(PrintStream(outStream))
+    try {
+        body()
+    } finally {
+        System.out.flush()
+        System.setOut(prevOut)
+    }
+    return outStream.toString()
+}