diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/compiler.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/compiler.kt
index 9bc10560112..6a78b2854b6 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/compiler.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/compiler.kt
@@ -10,7 +10,6 @@ import org.jetbrains.kotlin.backend.common.lower.*
 import org.jetbrains.kotlin.backend.common.runOnFilePostfix
 import org.jetbrains.kotlin.config.CompilerConfiguration
 import org.jetbrains.kotlin.descriptors.ModuleDescriptor
-import org.jetbrains.kotlin.descriptors.impl.ModuleDescriptorImpl
 import org.jetbrains.kotlin.ir.backend.js.lower.*
 import org.jetbrains.kotlin.ir.backend.js.lower.inline.*
 import org.jetbrains.kotlin.ir.backend.js.transformers.irToJs.IrModuleToJsTransformer
@@ -23,8 +22,6 @@ import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.progress.ProgressIndicatorAndCompilationCanceledStatus
 import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.psi2ir.Psi2IrTranslator
-import org.jetbrains.kotlin.serialization.js.JsModuleDescriptor
-import org.jetbrains.kotlin.serialization.js.ModuleKind
 
 data class Result(val moduleDescriptor: ModuleDescriptor, val generatedCode: String)
 
@@ -35,12 +32,8 @@ fun compile(
     export: FqName? = null,
     dependencies: List<ModuleDescriptor> = listOf()
 ): Result {
-    val moduleDescriptors =
-        dependencies
-            .filterIsInstance<ModuleDescriptorImpl>()
-            .map { JsModuleDescriptor("", ModuleKind.PLAIN, listOf(), it) }
-
-    val analysisResult = TopDownAnalyzerFacadeForJS.analyzeFiles(files, project, configuration, moduleDescriptors, emptyList())
+    val analysisResult =
+        TopDownAnalyzerFacadeForJS.analyzeFiles(files, project, configuration, dependencies.filterIsInstance(), emptyList())
 
     ProgressIndicatorAndCompilationCanceledStatus.checkCanceled()
 
diff --git a/compiler/tests-common/tests/org/jetbrains/kotlin/checkers/AbstractDiagnosticsTestWithJsStdLib.kt b/compiler/tests-common/tests/org/jetbrains/kotlin/checkers/AbstractDiagnosticsTestWithJsStdLib.kt
index a2899b35a83..8ea2f1d15ed 100644
--- a/compiler/tests-common/tests/org/jetbrains/kotlin/checkers/AbstractDiagnosticsTestWithJsStdLib.kt
+++ b/compiler/tests-common/tests/org/jetbrains/kotlin/checkers/AbstractDiagnosticsTestWithJsStdLib.kt
@@ -77,7 +77,7 @@ abstract class AbstractDiagnosticsTestWithJsStdLib : AbstractDiagnosticsTest() {
     }
 
     override fun getAdditionalDependencies(module: ModuleDescriptorImpl): List<ModuleDescriptorImpl> =
-            config.moduleDescriptors.map { it.data }
+        config.moduleDescriptors
 
     override fun shouldSkipJvmSignatureDiagnostics(groupedByModule: Map<TestModule?, List<TestFile>>): Boolean = true
 
diff --git a/compiler/tests/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializerTest.kt b/compiler/tests/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializerTest.kt
index fce2c0879a7..84694d7a997 100644
--- a/compiler/tests/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializerTest.kt
+++ b/compiler/tests/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializerTest.kt
@@ -33,6 +33,7 @@ import org.jetbrains.kotlin.js.config.JsConfig
 import org.jetbrains.kotlin.js.resolve.JsPlatform
 import org.jetbrains.kotlin.jvm.compiler.LoadDescriptorUtil.TEST_PACKAGE_FQNAME
 import org.jetbrains.kotlin.serialization.deserialization.DeserializationConfiguration
+import org.jetbrains.kotlin.serialization.js.KotlinJavascriptSerializationUtil.readModuleAsProto
 import org.jetbrains.kotlin.storage.LockBasedStorageManager
 import org.jetbrains.kotlin.test.KotlinTestUtils
 import org.jetbrains.kotlin.test.TestCaseWithTmpdir
@@ -94,9 +95,10 @@ class KotlinJavascriptSerializerTest : TestCaseWithTmpdir() {
         val metadata = KotlinJavascriptMetadataUtils.loadMetadata(metaFile)
         assert(metadata.size == 1)
 
-        val provider = KotlinJavascriptSerializationUtil.readModule(
-                metadata.single().body, LockBasedStorageManager(), module, DeserializationConfiguration.Default, LookupTracker.DO_NOTHING
-        ).data.sure { "No package fragment provider was created" }
+        val (header, packageFragmentProtos) = readModuleAsProto(metadata.single().body)
+        val provider = createKotlinJavascriptPackageFragmentProvider(
+            LockBasedStorageManager(), module, header, packageFragmentProtos, DeserializationConfiguration.Default, LookupTracker.DO_NOTHING
+        ).sure { "No package fragment provider was created" }
 
         module.initialize(provider)
         module.setDependencies(module, module.builtIns.builtInsModule)
diff --git a/idea/ide-common/src/org/jetbrains/kotlin/caches/resolve/JsAnalyzerFacade.kt b/idea/ide-common/src/org/jetbrains/kotlin/caches/resolve/JsAnalyzerFacade.kt
index 6df4c82c39d..d6da1f963ea 100644
--- a/idea/ide-common/src/org/jetbrains/kotlin/caches/resolve/JsAnalyzerFacade.kt
+++ b/idea/ide-common/src/org/jetbrains/kotlin/caches/resolve/JsAnalyzerFacade.kt
@@ -32,8 +32,8 @@ import org.jetbrains.kotlin.resolve.TargetEnvironment
 import org.jetbrains.kotlin.resolve.TargetPlatform
 import org.jetbrains.kotlin.resolve.lazy.ResolveSession
 import org.jetbrains.kotlin.resolve.lazy.declarations.DeclarationProviderFactoryService
-import org.jetbrains.kotlin.serialization.deserialization.DeserializationConfiguration
 import org.jetbrains.kotlin.serialization.js.KotlinJavascriptSerializationUtil
+import org.jetbrains.kotlin.serialization.js.createKotlinJavascriptPackageFragmentProvider
 import org.jetbrains.kotlin.utils.KotlinJavascriptMetadataUtils
 
 object JsAnalyzerFacade : ResolverForModuleFactory() {
@@ -72,11 +72,12 @@ object JsAnalyzerFacade : ResolverForModuleFactory() {
             val providers = moduleInfo.getLibraryRoots()
                 .flatMap { KotlinJavascriptMetadataUtils.loadMetadata(it) }
                 .filter { it.version.isCompatible() }
-                .mapNotNull {
-                    KotlinJavascriptSerializationUtil.readModule(
-                        it.body, moduleContext.storageManager, moduleDescriptor, container.get<DeserializationConfiguration>(),
-                        LookupTracker.DO_NOTHING
-                    ).data
+                .map { metadata ->
+                    val (header, packageFragmentProtos) = KotlinJavascriptSerializationUtil.readModuleAsProto(metadata.body)
+                    createKotlinJavascriptPackageFragmentProvider(
+                        moduleContext.storageManager, moduleDescriptor, header, packageFragmentProtos,
+                        container.get(), LookupTracker.DO_NOTHING
+                    )
                 }
 
             if (providers.isNotEmpty()) {
diff --git a/js/js.frontend/src/org/jetbrains/kotlin/js/analyze/TopDownAnalyzerFacadeForJS.kt b/js/js.frontend/src/org/jetbrains/kotlin/js/analyze/TopDownAnalyzerFacadeForJS.kt
index d8d95b248af..4ace02d8fa6 100644
--- a/js/js.frontend/src/org/jetbrains/kotlin/js/analyze/TopDownAnalyzerFacadeForJS.kt
+++ b/js/js.frontend/src/org/jetbrains/kotlin/js/analyze/TopDownAnalyzerFacadeForJS.kt
@@ -25,7 +25,6 @@ import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.resolve.*
 import org.jetbrains.kotlin.resolve.lazy.declarations.FileBasedDeclarationProviderFactory
-import org.jetbrains.kotlin.serialization.js.JsModuleDescriptor
 import org.jetbrains.kotlin.serialization.js.KotlinJavascriptSerializationUtil
 import org.jetbrains.kotlin.serialization.js.ModuleKind
 import org.jetbrains.kotlin.serialization.js.PackagesWithHeaderMetadata
@@ -56,8 +55,8 @@ object TopDownAnalyzerFacadeForJS {
         files: Collection<KtFile>,
         project: Project,
         configuration: CompilerConfiguration,
-        moduleDescriptors: List<JsModuleDescriptor<ModuleDescriptorImpl>>,
-        friendModuleDescriptors: List<JsModuleDescriptor<ModuleDescriptorImpl>>
+        moduleDescriptors: List<ModuleDescriptorImpl>,
+        friendModuleDescriptors: List<ModuleDescriptorImpl>
     ): JsAnalysisResult {
 
         val moduleName = configuration[CommonConfigurationKeys.MODULE_NAME]!!
@@ -65,9 +64,9 @@ object TopDownAnalyzerFacadeForJS {
 
         context.module.setDependencies(
             listOf(context.module) +
-                    moduleDescriptors.map { it.data } +
+                    moduleDescriptors +
                     listOf(JsPlatform.builtIns.builtInsModule),
-            friendModuleDescriptors.map { it.data }.toSet()
+            friendModuleDescriptors.toSet()
         )
 
         val moduleKind = configuration.get(JSConfigurationKeys.MODULE_KIND, ModuleKind.PLAIN)
diff --git a/js/js.frontend/src/org/jetbrains/kotlin/js/config/JsConfig.java b/js/js.frontend/src/org/jetbrains/kotlin/js/config/JsConfig.java
index ed09cf64b39..d41294593a8 100644
--- a/js/js.frontend/src/org/jetbrains/kotlin/js/config/JsConfig.java
+++ b/js/js.frontend/src/org/jetbrains/kotlin/js/config/JsConfig.java
@@ -33,10 +33,7 @@ import org.jetbrains.kotlin.incremental.components.LookupTracker;
 import org.jetbrains.kotlin.js.resolve.JsPlatform;
 import org.jetbrains.kotlin.name.Name;
 import org.jetbrains.kotlin.resolve.CompilerDeserializationConfiguration;
-import org.jetbrains.kotlin.serialization.js.JsModuleDescriptor;
-import org.jetbrains.kotlin.serialization.js.KotlinJavaScriptLibraryParts;
-import org.jetbrains.kotlin.serialization.js.KotlinJavascriptSerializationUtil;
-import org.jetbrains.kotlin.serialization.js.ModuleKind;
+import org.jetbrains.kotlin.serialization.js.*;
 import org.jetbrains.kotlin.storage.LockBasedStorageManager;
 import org.jetbrains.kotlin.utils.JsMetadataVersion;
 import org.jetbrains.kotlin.utils.KotlinJavascriptMetadata;
@@ -64,11 +61,8 @@ public class JsConfig {
     private final List<KotlinJavascriptMetadata> metadata = new SmartList<>();
     private final List<KotlinJavascriptMetadata> friends = new SmartList<>();
 
-    @Nullable
-    private List<JsModuleDescriptor<ModuleDescriptorImpl>> moduleDescriptors = null;
-
-    @Nullable
-    private List<JsModuleDescriptor<ModuleDescriptorImpl>> friendModuleDescriptors = null;
+    private List<ModuleDescriptorImpl> moduleDescriptors;
+    private List<ModuleDescriptorImpl> friendModuleDescriptors;
 
     private boolean initialized = false;
 
@@ -237,19 +231,16 @@ public class JsConfig {
     }
 
     @NotNull
-    public List<JsModuleDescriptor<ModuleDescriptorImpl>> getModuleDescriptors() {
+    public List<ModuleDescriptorImpl> getModuleDescriptors() {
         init();
         return moduleDescriptors;
     }
 
     @NotNull
-    private List<JsModuleDescriptor<ModuleDescriptorImpl>> createModuleDescriptors() {
-        List<JsModuleDescriptor<ModuleDescriptorImpl>> moduleDescriptors = new SmartList<>();
-        List<ModuleDescriptorImpl> kotlinModuleDescriptors = new ArrayList<>();
+    private List<ModuleDescriptorImpl> createModuleDescriptors() {
+        List<ModuleDescriptorImpl> moduleDescriptors = new SmartList<>();
         for (KotlinJavascriptMetadata metadataEntry : metadata) {
-            JsModuleDescriptor<ModuleDescriptorImpl> descriptor = createModuleDescriptor(metadataEntry);
-            moduleDescriptors.add(descriptor);
-            kotlinModuleDescriptors.add(descriptor.getData());
+            moduleDescriptors.add(createModuleDescriptor(metadataEntry));
         }
 
         if (metadataCache != null) {
@@ -259,50 +250,30 @@ public class JsConfig {
                         Name.special("<" + cached.getName() + ">"), storageManager, JsPlatform.INSTANCE.getBuiltIns()
                 );
 
-                JsModuleDescriptor<PackageFragmentProvider> rawDescriptor = KotlinJavascriptSerializationUtil.readModuleFromProto(
-                        cached, storageManager, moduleDescriptor,
+                PackageFragmentProvider provider = KotlinJavascriptPackageFragmentProviderKt.createKotlinJavascriptPackageFragmentProvider(
+                        storageManager, moduleDescriptor, cached.getData().getHeader(), cached.getData().getBody(),
                         new CompilerDeserializationConfiguration(languageVersionSettings),
                         LookupTracker.DO_NOTHING.INSTANCE
                 );
 
-                PackageFragmentProvider provider = rawDescriptor.getData();
-                moduleDescriptor.initialize(provider != null ? provider : PackageFragmentProvider.Empty.INSTANCE);
-
-                JsModuleDescriptor<ModuleDescriptorImpl> jsModuleDescriptor = cached.copy(moduleDescriptor);
-                moduleDescriptors.add(jsModuleDescriptor);
-                kotlinModuleDescriptors.add(jsModuleDescriptor.getData());
+                moduleDescriptor.initialize(provider);
+                moduleDescriptors.add(moduleDescriptor);
             }
         }
 
-        for (JsModuleDescriptor<ModuleDescriptorImpl> module : moduleDescriptors) {
-            // TODO: remove downcast
-            setDependencies(module.getData(), kotlinModuleDescriptors);
+        for (ModuleDescriptorImpl module : moduleDescriptors) {
+            setDependencies(module, moduleDescriptors);
         }
 
-        moduleDescriptors = Collections.unmodifiableList(moduleDescriptors);
-
-        return moduleDescriptors;
+        return Collections.unmodifiableList(moduleDescriptors);
     }
 
     @NotNull
-    public List<JsModuleDescriptor<ModuleDescriptorImpl>> getFriendModuleDescriptors() {
+    public List<ModuleDescriptorImpl> getFriendModuleDescriptors() {
         init();
         return friendModuleDescriptors;
     }
 
-    @NotNull
-    private List<JsModuleDescriptor<ModuleDescriptorImpl>> createFriendModuleDescriptors() {
-        List<JsModuleDescriptor<ModuleDescriptorImpl>> friendModuleDescriptors = new SmartList<>();
-        for (KotlinJavascriptMetadata metadataEntry : friends) {
-            JsModuleDescriptor<ModuleDescriptorImpl> descriptor = createModuleDescriptor(metadataEntry);
-            friendModuleDescriptors.add(descriptor);
-        }
-
-        friendModuleDescriptors = Collections.unmodifiableList(friendModuleDescriptors);
-
-        return friendModuleDescriptors;
-    }
-
     public void init() {
         if (!initialized) {
             JsConfig.Reporter reporter = new Reporter() {
@@ -320,13 +291,13 @@ public class JsConfig {
         }
 
         if (friendModuleDescriptors == null) {
-            friendModuleDescriptors = createFriendModuleDescriptors();
+            friendModuleDescriptors = CollectionsKt.map(friends, this::createModuleDescriptor);
         }
     }
 
-    private final IdentityHashMap<KotlinJavascriptMetadata, JsModuleDescriptor<ModuleDescriptorImpl>> factoryMap = new IdentityHashMap<>();
+    private final IdentityHashMap<KotlinJavascriptMetadata, ModuleDescriptorImpl> factoryMap = new IdentityHashMap<>();
 
-    private JsModuleDescriptor<ModuleDescriptorImpl> createModuleDescriptor(KotlinJavascriptMetadata metadata) {
+    private ModuleDescriptorImpl createModuleDescriptor(KotlinJavascriptMetadata metadata) {
         return factoryMap.computeIfAbsent(metadata, m -> {
             LanguageVersionSettings languageVersionSettings = CommonConfigurationKeysKt.getLanguageVersionSettings(configuration);
             assert m.getVersion().isCompatible() ||
@@ -338,16 +309,15 @@ public class JsConfig {
             );
 
             LookupTracker lookupTracker = configuration.get(CommonConfigurationKeys.LOOKUP_TRACKER, LookupTracker.DO_NOTHING.INSTANCE);
-            JsModuleDescriptor<PackageFragmentProvider> rawDescriptor = KotlinJavascriptSerializationUtil.readModule(
-                    m.getBody(), storageManager, moduleDescriptor,
+            KotlinJavaScriptLibraryParts parts = KotlinJavascriptSerializationUtil.readModuleAsProto(m.getBody());
+            PackageFragmentProvider provider = KotlinJavascriptPackageFragmentProviderKt.createKotlinJavascriptPackageFragmentProvider(
+                    storageManager, moduleDescriptor, parts.getHeader(), parts.getBody(),
                     new CompilerDeserializationConfiguration(languageVersionSettings),
                     lookupTracker
             );
 
-            PackageFragmentProvider provider = rawDescriptor.getData();
-            moduleDescriptor.initialize(provider != null ? provider : PackageFragmentProvider.Empty.INSTANCE);
-
-            return rawDescriptor.copy(moduleDescriptor);
+            moduleDescriptor.initialize(provider);
+            return moduleDescriptor;
         });
     }
 
diff --git a/js/js.serializer/src/org/jetbrains/kotlin/serialization/js/JsModuleDescriptor.kt b/js/js.serializer/src/org/jetbrains/kotlin/serialization/js/JsModuleDescriptor.kt
index ee7cde33b8d..1919d700d5e 100644
--- a/js/js.serializer/src/org/jetbrains/kotlin/serialization/js/JsModuleDescriptor.kt
+++ b/js/js.serializer/src/org/jetbrains/kotlin/serialization/js/JsModuleDescriptor.kt
@@ -16,6 +16,9 @@
 
 package org.jetbrains.kotlin.serialization.js
 
-class JsModuleDescriptor<out T>(val name: String, val kind: ModuleKind, val imported: List<String>, val data: T) {
-    fun <S> copy(newData: S) = JsModuleDescriptor(name, kind, imported, newData)
-}
+class JsModuleDescriptor<out T>(
+    val name: String,
+    val kind: ModuleKind,
+    val imported: List<String>,
+    val data: T
+)
diff --git a/js/js.serializer/src/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializationUtil.kt b/js/js.serializer/src/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializationUtil.kt
index b39b036fcb5..fddce0577af 100644
--- a/js/js.serializer/src/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializationUtil.kt
+++ b/js/js.serializer/src/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializationUtil.kt
@@ -51,34 +51,6 @@ import java.util.zip.GZIPOutputStream
 object KotlinJavascriptSerializationUtil {
     const val CLASS_METADATA_FILE_EXTENSION: String = "kjsm"
 
-    @JvmStatic
-    fun readModule(
-        metadata: ByteArray,
-        storageManager: StorageManager,
-        module: ModuleDescriptor,
-        configuration: DeserializationConfiguration,
-        lookupTracker: LookupTracker
-    ): JsModuleDescriptor<PackageFragmentProvider?> =
-        readModuleFromProto(readModuleAsProto(metadata, module.name.asString()), storageManager, module, configuration, lookupTracker)
-
-    fun readModuleAsProto(metadata: ByteArray, name: String): JsModuleDescriptor<KotlinJavaScriptLibraryParts> =
-        metadata.deserializeToLibraryParts(name)
-
-    @JvmStatic
-    fun readModuleFromProto(
-        jsModule: JsModuleDescriptor<KotlinJavaScriptLibraryParts>,
-        storageManager: StorageManager, module: ModuleDescriptor,
-        configuration: DeserializationConfiguration,
-        lookupTracker: LookupTracker
-    ): JsModuleDescriptor<PackageFragmentProvider?> {
-        val (header, packageFragmentProtos) = jsModule.data
-        return jsModule.copy(
-            createKotlinJavascriptPackageFragmentProvider(
-                storageManager, module, header, packageFragmentProtos, configuration, lookupTracker
-            )
-        )
-    }
-
     fun readDescriptors(
         metadata: PackagesWithHeaderMetadata,
         storageManager: StorageManager,
@@ -334,27 +306,30 @@ object KotlinJavascriptSerializationUtil {
         }
     }
 
-    private fun ByteArray.deserializeToLibraryParts(name: String): JsModuleDescriptor<KotlinJavaScriptLibraryParts> {
-        val (header, content) = GZIPInputStream(ByteArrayInputStream(this)).use { stream ->
+    @JvmStatic
+    fun readModuleAsProto(metadata: ByteArray): KotlinJavaScriptLibraryParts {
+        val (header, content) = GZIPInputStream(ByteArrayInputStream(metadata)).use { stream ->
             JsProtoBuf.Header.parseDelimitedFrom(stream, JsSerializerProtocol.extensionRegistry) to
                     JsProtoBuf.Library.parseFrom(stream, JsSerializerProtocol.extensionRegistry)
         }
 
-        return JsModuleDescriptor(
-            name = name,
-            data = KotlinJavaScriptLibraryParts(header, content.packageFragmentList),
-            kind = when (content.kind) {
-                null, JsProtoBuf.Library.Kind.PLAIN -> ModuleKind.PLAIN
-                JsProtoBuf.Library.Kind.AMD -> ModuleKind.AMD
-                JsProtoBuf.Library.Kind.COMMON_JS -> ModuleKind.COMMON_JS
-                JsProtoBuf.Library.Kind.UMD -> ModuleKind.UMD
-            },
-            imported = content.importedModuleList
-        )
+        val moduleKind = when (content.kind) {
+            null, JsProtoBuf.Library.Kind.PLAIN -> ModuleKind.PLAIN
+            JsProtoBuf.Library.Kind.AMD -> ModuleKind.AMD
+            JsProtoBuf.Library.Kind.COMMON_JS -> ModuleKind.COMMON_JS
+            JsProtoBuf.Library.Kind.UMD -> ModuleKind.UMD
+        }
+
+        return KotlinJavaScriptLibraryParts(header, content.packageFragmentList, moduleKind, content.importedModuleList)
     }
 }
 
-data class KotlinJavaScriptLibraryParts(val header: JsProtoBuf.Header, val body: List<ProtoBuf.PackageFragment>)
+data class KotlinJavaScriptLibraryParts(
+    val header: JsProtoBuf.Header,
+    val body: List<ProtoBuf.PackageFragment>,
+    val kind: ModuleKind,
+    val importedModules: List<String>
+)
 
 internal fun DeclarationDescriptor.extractFileId(): Int? = when (this) {
     is DeserializedClassDescriptor -> classProto.getExtension(JsProtoBuf.classContainingFileId)
diff --git a/js/js.tests/test/org/jetbrains/kotlin/js/test/BasicBoxTest.kt b/js/js.tests/test/org/jetbrains/kotlin/js/test/BasicBoxTest.kt
index 8f18fb074d6..9770ca94417 100644
--- a/js/js.tests/test/org/jetbrains/kotlin/js/test/BasicBoxTest.kt
+++ b/js/js.tests/test/org/jetbrains/kotlin/js/test/BasicBoxTest.kt
@@ -49,6 +49,7 @@ import org.jetbrains.kotlin.metadata.DebugProtoBuf
 import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.psi.KtNamedFunction
 import org.jetbrains.kotlin.psi.KtPsiFactory
+import org.jetbrains.kotlin.serialization.js.JsModuleDescriptor
 import org.jetbrains.kotlin.serialization.js.JsSerializerProtocol
 import org.jetbrains.kotlin.serialization.js.KotlinJavascriptSerializationUtil
 import org.jetbrains.kotlin.serialization.js.ModuleKind
@@ -394,9 +395,11 @@ abstract class BasicBoxTest(
             val originalMetadata = FileUtil.loadFile(File(outputFile.parentFile, outputFile.nameWithoutExtension + ".meta.js"))
             val recompiledMetadata = removeRecompiledSuffix(
                     FileUtil.loadFile(File(recompiledOutputFile.parentFile, recompiledOutputFile.nameWithoutExtension + ".meta.js")))
-            assertEquals("Metadata file changed after recompilation",
-                                  metadataAsString(originalMetadata, module.name),
-                                  metadataAsString(recompiledMetadata, module.name))
+            assertEquals(
+                "Metadata file changed after recompilation",
+                metadataAsString(originalMetadata),
+                metadataAsString(recompiledMetadata)
+            )
         }
     }
 
@@ -406,10 +409,10 @@ abstract class BasicBoxTest(
         return String(out.toByteArray(), Charset.forName("UTF-8"))
     }
 
-    private fun metadataAsString(metadata: String, moduleName: String): String {
+    private fun metadataAsString(metadata: String): String {
         val containers = mutableListOf<KotlinJavascriptMetadata>()
         KotlinJavascriptMetadataUtils.parseMetadata(metadata, containers)
-        val metadataParts = KotlinJavascriptSerializationUtil.readModuleAsProto(containers.single().body, moduleName).data.body
+        val metadataParts = KotlinJavascriptSerializationUtil.readModuleAsProto(containers.single().body).body
         return metadataParts.joinToString("-----\n") {
             val binary = it.toByteArray()
             DebugProtoBuf.PackageFragment.parseFrom(binary, JsSerializerProtocol.extensionRegistry).toString()
@@ -738,13 +741,12 @@ abstract class BasicBoxTest(
             KotlinCoreEnvironment.createForTests(testRootDisposable, CompilerConfiguration(), EnvironmentConfigFiles.JS_CONFIG_FILES)
 
     companion object {
-        val METADATA_CACHE = (JsConfig.JS_STDLIB.asSequence() + JsConfig.JS_KOTLIN_TEST)
-                .flatMap {
-                    KotlinJavascriptMetadataUtils
-                            .loadMetadata(it).asSequence()
-                            .map { KotlinJavascriptSerializationUtil.readModuleAsProto(it.body, it.moduleName) }
-                }
-                .toList()
+        val METADATA_CACHE = (JsConfig.JS_STDLIB + JsConfig.JS_KOTLIN_TEST).flatMap { path ->
+            KotlinJavascriptMetadataUtils.loadMetadata(path).map { metadata ->
+                val parts = KotlinJavascriptSerializationUtil.readModuleAsProto(metadata.body)
+                JsModuleDescriptor(metadata.moduleName, parts.kind, parts.importedModules, parts)
+            }
+        }
 
         const val TEST_DATA_DIR_PATH = "js/js.translator/testData/"
         const val DIST_DIR_JS_PATH = "dist/js/"