Implement script dependencies resolution directly from classloader

#KT-27956 fixed

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

@@ -38,6 +38,7 @@ sourceSets {
 }
 
 projectTest(parallel = true) {
+    dependsOn(":dist")
     workingDir = rootDir
 }
 

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

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * 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 junit.framework.TestCase
+import org.junit.Test
+import java.io.File
+import kotlin.script.experimental.api.ResultValue
+import kotlin.script.experimental.api.ScriptCompilationConfiguration
+import kotlin.script.experimental.api.dependencies
+import kotlin.script.experimental.api.valueOrThrow
+import kotlin.script.experimental.host.toScriptSource
+import kotlin.script.experimental.jvm.JvmDependency
+import kotlin.script.experimental.jvm.JvmDependencyFromClassLoader
+import kotlin.script.experimental.jvmhost.BasicJvmScriptingHost
+
+class ResolveFromClassloaderTest : TestCase() {
+
+    @Test
+    fun testResolveFromClassloader() {
+        val script = "${ShouldBeVisibleFromScript::class.java.name}().x".toScriptSource()
+        val compilationConfiguration = ScriptCompilationConfiguration {
+            dependencies(JvmDependencyFromClassLoader { ShouldBeVisibleFromScript::class.java.classLoader })
+        }
+        val res = BasicJvmScriptingHost().eval(script, compilationConfiguration, null).valueOrThrow().returnValue as ResultValue.Value
+        assertEquals(42, res.value)
+    }
+
+    @Test
+    fun testResolveFromClassloaderAndClassPath() {
+        val script = """
+            org.jetbrains.kotlin.mainKts.MainKtsConfigurator()
+            ${ShouldBeVisibleFromScript::class.java.name}().x
+        """.trimIndent().toScriptSource()
+        val classpath = listOf(
+            File("dist/kotlinc/lib/kotlin-main-kts.jar").also {
+                assertTrue("kotlin-main-kts.jar not found, run dist task: ${it.absolutePath}", it.exists())
+            }
+        )
+        val compilationConfiguration = ScriptCompilationConfiguration {
+            dependencies(
+                JvmDependencyFromClassLoader { ShouldBeVisibleFromScript::class.java.classLoader },
+                JvmDependency(classpath)
+            )
+        }
+        val res = BasicJvmScriptingHost().eval(script, compilationConfiguration, null).valueOrThrow().returnValue as ResultValue.Value
+        assertEquals(42, res.value)
+    }
+}
+
+@Suppress("unused")
+class ShouldBeVisibleFromScript {
+    val x = 42
+}

libraries/scripting/jvm/src/kotlin/script/experimental/jvm/impl/BridgeDependenciesResolver.kt

@@ -97,7 +97,7 @@ internal fun ScriptContents.toScriptSource(): SourceCode = when {
     else -> throw IllegalArgumentException("Unable to convert script contents $this into script source")
 }
 
-fun List<ScriptDependency>?.toClassPathOrEmpty() = this?.flatMap { (it as JvmDependency).classpath } ?: emptyList()
+fun List<ScriptDependency>?.toClassPathOrEmpty() = this?.flatMap { (it as? JvmDependency)?.classpath ?: emptyList() } ?: emptyList()
 
 internal fun List<SourceCode>?.toFilesOrEmpty() = this?.map {
     val externalSource = it as? ExternalSourceCode

libraries/scripting/jvm/src/kotlin/script/experimental/jvm/jvmScriptCompilation.kt

@@ -19,6 +19,12 @@ data class JvmDependency(val classpath: List<File>) : ScriptDependency {
     companion object { private const val serialVersionUID: Long = 1L }
 }
 
+typealias ClassLoaderByConfiguration = (ScriptCompilationConfiguration) -> ClassLoader
+
+class JvmDependencyFromClassLoader(val classLoaderGetter: ClassLoaderByConfiguration) : ScriptDependency {
+    fun getClassLoader(configuration: ScriptCompilationConfiguration): ClassLoader = classLoaderGetter(configuration)
+}
+
 interface JvmScriptCompilationConfigurationKeys
 
 open class JvmScriptCompilationConfigurationBuilder : PropertiesCollection.Builder(), JvmScriptCompilationConfigurationKeys {