postpone isJsProject() check

#KT-9026 Fixed

idea/idea-analysis/src/org/jetbrains/kotlin/idea/stubindex/KotlinSourceFilterScope.java

@@ -19,11 +19,11 @@ package org.jetbrains.kotlin.idea.stubindex;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.roots.ProjectFileIndex;
 import com.intellij.openapi.roots.ProjectRootManager;
+import com.intellij.openapi.util.Ref;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.psi.search.DelegatingGlobalSearchScope;
 import com.intellij.psi.search.GlobalSearchScope;
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.kotlin.idea.caches.resolve.JsProjectDetector;
 import org.jetbrains.kotlin.idea.util.ProjectRootsUtil;
 
 public class KotlinSourceFilterScope extends DelegatingGlobalSearchScope {
@@ -84,7 +84,9 @@ public class KotlinSourceFilterScope extends DelegatingGlobalSearchScope {
     private final boolean includeProjectSourceFiles;
     private final boolean includeLibrarySourceFiles;
     private final boolean includeClassFiles;
-    private final boolean isJsProject;
+
+    //NOTE: avoid recomputing in potentially bottleneck 'contains' method
+    private final Ref<Boolean> isJsProjectRef = new Ref<Boolean>();
 
     private KotlinSourceFilterScope(
             @NotNull GlobalSearchScope delegate,
@@ -98,9 +100,7 @@ public class KotlinSourceFilterScope extends DelegatingGlobalSearchScope {
         this.includeProjectSourceFiles = includeProjectSourceFiles;
         this.includeLibrarySourceFiles = includeLibrarySourceFiles;
         this.includeClassFiles = includeClassFiles;
-        //NOTE: avoid recomputing in potentially bottleneck 'contains' method
         this.index = ProjectRootManager.getInstance(project).getFileIndex();
-        this.isJsProject = JsProjectDetector.isJsProject(project);
     }
 
     @Override
@@ -112,7 +112,7 @@ public class KotlinSourceFilterScope extends DelegatingGlobalSearchScope {
     public boolean contains(@NotNull VirtualFile file) {
         if (!super.contains(file)) return false;
         return ProjectRootsUtil.isInContent(
-                project, file, includeProjectSourceFiles, includeLibrarySourceFiles, includeClassFiles, index, isJsProject
+                project, file, includeProjectSourceFiles, includeLibrarySourceFiles, includeClassFiles, index, isJsProjectRef
         );
     }
 }

idea/idea-analysis/src/org/jetbrains/kotlin/idea/util/ProjectRootsUtil.kt

@@ -19,6 +19,7 @@ package org.jetbrains.kotlin.idea.util
 import com.intellij.ide.highlighter.JavaClassFileType
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.roots.ProjectFileIndex
+import com.intellij.openapi.util.Ref
 import com.intellij.openapi.vfs.VirtualFile
 import com.intellij.psi.PsiDirectory
 import com.intellij.psi.PsiElement
@@ -33,21 +34,30 @@ object ProjectRootsUtil {
     @JvmStatic fun isInContent(project: Project, file: VirtualFile, includeProjectSource: Boolean,
                                includeLibrarySource: Boolean, includeLibraryClasses: Boolean,
                                fileIndex: ProjectFileIndex = ProjectFileIndex.SERVICE.getInstance(project),
-                               isJsProject: Boolean? = null): Boolean {
+                               isJsProjectRef: Ref<Boolean?>? = null): Boolean {
         if (includeProjectSource && fileIndex.isInSourceContent(file)) {
             return true
         }
-        if (!includeLibraryClasses && !includeLibrarySource) return false
 
-        //NOTE: avoid computing isJsProject if redundant
-        if (isJsProject ?: JsProjectDetector.isJsProject(project)) {
-            return (includeLibrarySource && fileIndex.isInLibrarySource(file))
-                   || (includeLibraryClasses && fileIndex.isLibraryClassFile(file))
-        }
         // NOTE: the following is a workaround for cases when class files are under library source roots and source files are under class roots
         val isClassFile = file.fileType in classFileLike
-        return (includeLibraryClasses && isClassFile && fileIndex.isInLibraryClasses(file))
-               || (includeLibrarySource && !isClassFile && fileIndex.isInLibrarySource(file))
+
+        if ((includeLibraryClasses && isClassFile && fileIndex.isInLibraryClasses(file)) ||
+            (includeLibrarySource && !isClassFile && fileIndex.isInLibrarySource(file))) {
+
+            return true
+        }
+
+        if ((includeLibraryClasses && fileIndex.isInLibraryClasses(file)) ||
+            (includeLibrarySource && fileIndex.isInLibrarySource(file))) {
+
+            //NOTE: avoid computing isJsProject if redundant
+            val isJsProject = isJsProjectRef?.get() ?: JsProjectDetector.isJsProject(project)
+            isJsProjectRef?.set(isJsProject)
+            return isJsProject
+        }
+
+        return false
     }
 
     @JvmStatic fun isInContent(