diff --git a/build-common/src/org/jetbrains/kotlin/incremental/IncrementalJsCache.kt b/build-common/src/org/jetbrains/kotlin/incremental/IncrementalJsCache.kt
index 2771433718b..1cfec636e00 100644
--- a/build-common/src/org/jetbrains/kotlin/incremental/IncrementalJsCache.kt
+++ b/build-common/src/org/jetbrains/kotlin/incremental/IncrementalJsCache.kt
@@ -24,12 +24,14 @@ import org.jetbrains.kotlin.incremental.storage.*
 import org.jetbrains.kotlin.metadata.ProtoBuf
 import org.jetbrains.kotlin.metadata.deserialization.NameResolverImpl
 import org.jetbrains.kotlin.metadata.deserialization.getExtensionOrNull
+import org.jetbrains.kotlin.metadata.js.JsProtoBuf
 import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.name.parentOrNull
 import org.jetbrains.kotlin.serialization.SerializerExtensionProtocol
 import org.jetbrains.kotlin.serialization.deserialization.getClassId
+import org.jetbrains.kotlin.serialization.js.JsSerializerProtocol
 import java.io.DataInput
 import java.io.DataOutput
 import java.io.File
@@ -321,6 +323,26 @@ private class ProtoDataProvider(private val serializerProtocol: SerializerExtens
     }
 }
 
+// TODO: remove this method once AbstractJsProtoComparisonTest is fixed
+fun getProtoData(sourceFile: File, metadata: ByteArray): Map<ClassId, ProtoData> {
+    val classes = hashMapOf<ClassId, ProtoData>()
+    val proto = ProtoBuf.PackageFragment.parseFrom(metadata, JsSerializerProtocol.extensionRegistry)
+    val nameResolver = NameResolverImpl(proto.strings, proto.qualifiedNames)
+
+    proto.class_List.forEach {
+        val classId = nameResolver.getClassId(it.fqName)
+        classes[classId] = ClassProtoData(it, nameResolver)
+    }
+
+    proto.`package`.apply {
+        val packageFqName = getExtensionOrNull(JsProtoBuf.packageFqName)?.let(nameResolver::getPackageFqName)?.let(::FqName) ?: FqName.ROOT
+        val packagePartClassId = ClassId(packageFqName, Name.identifier(sourceFile.nameWithoutExtension.capitalize() + "Kt"))
+        classes[packagePartClassId] = PackagePartProtoData(this, nameResolver, packageFqName)
+    }
+
+    return classes
+}
+
 private class InlineFunctionsMap(
     storageFile: File,
     private val pathConverter: FileToPathConverter