diff --git a/idea/tests/org/jetbrains/jet/plugin/JdkAndMockLibraryProjectDescriptor.java b/idea/tests/org/jetbrains/jet/plugin/JdkAndMockLibraryProjectDescriptor.java
index 95bc50a31b1..49282ca6d2d 100644
--- a/idea/tests/org/jetbrains/jet/plugin/JdkAndMockLibraryProjectDescriptor.java
+++ b/idea/tests/org/jetbrains/jet/plugin/JdkAndMockLibraryProjectDescriptor.java
@@ -1,35 +1,13 @@
 package org.jetbrains.jet.plugin;
 
-import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.module.Module;
 import com.intellij.openapi.roots.ContentEntry;
 import com.intellij.openapi.roots.ModifiableRootModel;
 import com.intellij.openapi.roots.OrderRootType;
 import com.intellij.openapi.roots.libraries.Library;
-import com.intellij.openapi.util.ThrowableComputable;
-import com.intellij.openapi.util.io.FileUtil;
-import com.intellij.openapi.vfs.LocalFileSystem;
-import com.intellij.openapi.vfs.VfsUtilCore;
-import com.intellij.openapi.vfs.VirtualFile;
-import com.intellij.openapi.vfs.VirtualFileVisitor;
-import com.intellij.openapi.vfs.newvfs.NewVirtualFile;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.jet.JetTestUtils;
-import org.jetbrains.jet.cli.common.ExitCode;
-import org.jetbrains.jet.cli.jvm.K2JVMCompiler;
-import org.jetbrains.jet.utils.ExceptionUtils;
-import org.jetbrains.jet.utils.PathUtil;
+import com.intellij.openapi.util.io.FileUtilRt;
 
-import java.io.ByteArrayOutputStream;
 import java.io.File;
-import java.io.IOException;
-import java.io.PrintStream;
-import java.lang.reflect.Method;
-import java.net.URL;
-import java.net.URLClassLoader;
-
-import static junit.framework.Assert.assertEquals;
-import static junit.framework.Assert.assertNotNull;
 
 public class JdkAndMockLibraryProjectDescriptor extends JetLightProjectDescriptor {
     private final String sourcesPath;
@@ -42,76 +20,15 @@ public class JdkAndMockLibraryProjectDescriptor extends JetLightProjectDescripto
 
     @Override
     public void configureModule(Module module, ModifiableRootModel model, ContentEntry contentEntry) {
-        try {
-            File compiledDir = compileTestLibrary(sourcesPath);
+        File libraryJar = MockLibraryUtil.compileLibraryToJar(sourcesPath);
+        String jarUrl = "jar://" + FileUtilRt.toSystemIndependentName(libraryJar.getAbsolutePath()) + "!/";
 
-            final VirtualFile baseDir = module.getProject().getBaseDir();
-            assertNotNull(baseDir);
-
-            VirtualFile libraryDir = ApplicationManager.getApplication().runWriteAction(new ThrowableComputable<VirtualFile, IOException>() {
-                @Override
-                public VirtualFile compute() throws IOException {
-                    VirtualFile libraryDir = baseDir.createChildDirectory(this, "lib");
-                    baseDir.createChildDirectory(this, "src");
-                    return libraryDir;
-                }
-            });
-
-            VirtualFile testDataDir = LocalFileSystem.getInstance().findFileByPath(sourcesPath).getParent();
-            assertNotNull(testDataDir);
-            VfsUtilCore.visitChildrenRecursively(testDataDir, new VirtualFileVisitor() {
-                @Override
-                public boolean visitFile(@NotNull VirtualFile file) {
-                    file.getChildren();
-                    file.refresh(false, true);
-                    return true;
-                }
-            });
-            VirtualFile librarySourceDir = LocalFileSystem.getInstance().findFileByPath(sourcesPath);
-            assertNotNull(librarySourceDir);
-
-            FileUtil.copyDir(compiledDir, new File(libraryDir.getPath()));
-
-            ((NewVirtualFile)baseDir).markDirtyRecursively();
-            baseDir.refresh(false, true);
-
-            Library.ModifiableModel libraryModel = model.getModuleLibraryTable().getModifiableModel().createLibrary("myKotlinLib").getModifiableModel();
-            libraryModel.addRoot(libraryDir, OrderRootType.CLASSES);
-            if (withSources) {
-                libraryModel.addRoot(librarySourceDir, OrderRootType.SOURCES);
-            }
-            libraryModel.commit();
-        }
-        catch (IOException e) {
-            throw new AssertionError(e);
-        }
-    }
-
-    private static File compileTestLibrary(String sourcesPath) {
-        try {
-            File compiledDir = JetTestUtils.tmpDir("dummylib");
-
-            ByteArrayOutputStream outStream = new ByteArrayOutputStream();
-
-            File kotlinCompilerJar = new File(PathUtil.getKotlinPathsForDistDirectory().getLibPath(), "kotlin-compiler.jar");
-            URLClassLoader classLoader = new URLClassLoader(new URL[] {kotlinCompilerJar.toURI().toURL()}, Object.class.getClassLoader());
-
-            Class<?> compilerClass = classLoader.loadClass(K2JVMCompiler.class.getName());
-            Object compilerObject = compilerClass.newInstance();
-            Method execMethod = compilerClass.getMethod("exec", PrintStream.class, String[].class);
-
-            //noinspection IOResourceOpenedButNotSafelyClosed
-            Enum<?> invocationResult = (Enum<?>) execMethod
-                    .invoke(compilerObject, new PrintStream(outStream),
-                            new String[] {"-src", sourcesPath, "-output", compiledDir.getAbsolutePath()});
-
-            assertEquals(new String(outStream.toByteArray()), ExitCode.OK.name(), invocationResult.name());
-
-            return compiledDir;
-        }
-        catch (Throwable e) {
-            throw ExceptionUtils.rethrow(e);
+        Library.ModifiableModel libraryModel = model.getModuleLibraryTable().getModifiableModel().createLibrary("myKotlinLib").getModifiableModel();
+        libraryModel.addRoot(jarUrl, OrderRootType.CLASSES);
+        if (withSources) {
+            libraryModel.addRoot(jarUrl + "src/", OrderRootType.SOURCES);
         }
+        libraryModel.commit();
     }
 
 
diff --git a/idea/tests/org/jetbrains/jet/plugin/MockLibraryUtil.java b/idea/tests/org/jetbrains/jet/plugin/MockLibraryUtil.java
new file mode 100644
index 00000000000..e8de8dffb02
--- /dev/null
+++ b/idea/tests/org/jetbrains/jet/plugin/MockLibraryUtil.java
@@ -0,0 +1,65 @@
+package org.jetbrains.jet.plugin;
+
+import com.intellij.util.io.ZipUtil;
+import org.jetbrains.jet.JetTestUtils;
+import org.jetbrains.jet.cli.common.ExitCode;
+import org.jetbrains.jet.cli.jvm.K2JVMCompiler;
+import org.jetbrains.jet.utils.ExceptionUtils;
+import org.jetbrains.jet.utils.PathUtil;
+
+import java.io.*;
+import java.lang.reflect.Method;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.util.zip.ZipOutputStream;
+
+import static junit.framework.Assert.assertEquals;
+
+public class MockLibraryUtil {
+    public static File compileLibraryToJar(String sourcesPath) {
+        try {
+            File contentDir = JetTestUtils.tmpDir("lib-content");
+
+            File classesDir = new File(contentDir, "classes");
+            compile(sourcesPath, classesDir);
+
+            File jarFile = new File(contentDir, "library.jar");
+
+            ZipOutputStream zip = new ZipOutputStream(new FileOutputStream(jarFile));
+            ZipUtil.addDirToZipRecursively(zip, jarFile, classesDir, "", null, null);
+            ZipUtil.addDirToZipRecursively(zip, jarFile, new File(sourcesPath), "src", null, null);
+            zip.close();
+
+            return jarFile;
+        }
+        catch (IOException e) {
+            throw ExceptionUtils.rethrow(e);
+        }
+    }
+
+    private static void compile(String sourcesPath, File outDir) {
+        try {
+            ByteArrayOutputStream outStream = new ByteArrayOutputStream();
+
+            File kotlinCompilerJar = new File(PathUtil.getKotlinPathsForDistDirectory().getLibPath(), "kotlin-compiler.jar");
+            URLClassLoader classLoader = new URLClassLoader(new URL[] {kotlinCompilerJar.toURI().toURL()}, Object.class.getClassLoader());
+
+            Class<?> compilerClass = classLoader.loadClass(K2JVMCompiler.class.getName());
+            Object compilerObject = compilerClass.newInstance();
+            Method execMethod = compilerClass.getMethod("exec", PrintStream.class, String[].class);
+
+            //noinspection IOResourceOpenedButNotSafelyClosed
+            Enum<?> invocationResult = (Enum<?>) execMethod
+                    .invoke(compilerObject, new PrintStream(outStream),
+                            new String[] {"-src", sourcesPath, "-output", outDir.getAbsolutePath()});
+
+            assertEquals(new String(outStream.toByteArray()), ExitCode.OK.name(), invocationResult.name());
+        }
+        catch (Throwable e) {
+            throw ExceptionUtils.rethrow(e);
+        }
+    }
+
+    private MockLibraryUtil() {
+    }
+}