Check type alias expansion for Java 9 module accessibility

#KT-18598 In Progress

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/checkers/JvmModuleAccessibilityChecker.kt

@@ -117,15 +117,23 @@ class JvmModuleAccessibilityChecker(project: Project) : CallChecker {
                 element: PsiElement,
                 languageVersionSettings: LanguageVersionSettings
         ) {
-            val targetClassOrPackage = when (targetDescriptor) {
+            val virtualFile = element.containingFile.virtualFile
-                is ClassDescriptor -> targetDescriptor
+            when (targetDescriptor) {
-                is TypeAliasDescriptor -> {
+                is ClassDescriptor -> {
-                    DescriptorUtils.getParentOfType(targetDescriptor, ClassOrPackageFragmentDescriptor::class.java) ?: return
+                    diagnosticFor(targetDescriptor, targetDescriptor, virtualFile, element)?.let(trace::report)
                 }
-                else -> return
+                is TypeAliasDescriptor -> {
-            }
+                    val containingClassOrPackage = DescriptorUtils.getParentOfType(targetDescriptor, ClassOrPackageFragmentDescriptor::class.java)
+                    if (containingClassOrPackage != null) {
+                        diagnosticFor(containingClassOrPackage, targetDescriptor, virtualFile, element)?.let(trace::report)
+                    }
 
-            diagnosticFor(targetClassOrPackage, targetDescriptor, element.containingFile.virtualFile, element)?.let(trace::report)
+                    val expandedClass = targetDescriptor.expandedType.constructor.declarationDescriptor as? ClassDescriptor
+                    if (expandedClass != null) {
+                        diagnosticFor(expandedClass, expandedClass, virtualFile, element)?.let(trace::report)
+                    }
+                }
+            }
         }
     }
 }

idea/testData/multiModuleHighlighting/java9/typealiasToUnexported/dependency/exported/exported.kt

@@ -0,0 +1,6 @@
+package exported
+
+import unexported.*
+
+typealias AliasToUnexported = Unexported
+typealias AliasToListOfUnexported = List<AliasToUnexported>

idea/testData/multiModuleHighlighting/java9/typealiasToUnexported/dependency/module-info.java

@@ -0,0 +1,3 @@
+module dependency {
+    exports exported;
+}

idea/testData/multiModuleHighlighting/java9/typealiasToUnexported/dependency/unexported/unexported.kt

@@ -0,0 +1,3 @@
+package unexported
+
+class Unexported

idea/testData/multiModuleHighlighting/java9/typealiasToUnexported/main/module-info.java

@@ -0,0 +1,3 @@
+module main {
+    requires dependency;
+}

idea/testData/multiModuleHighlighting/java9/typealiasToUnexported/main/usage.kt

@@ -0,0 +1,4 @@
+import exported.*
+
+fun f1(): <error>AliasToUnexported</error>? = null
+fun f2(): AliasToListOfUnexported? = null

idea/tests/org/jetbrains/kotlin/idea/caches/resolve/Java9MultiModuleHighlightingTest.kt

@@ -78,4 +78,9 @@ class Java9MultiModuleHighlightingTest : AbstractMultiModuleHighlightingTest() {
         module("main").addDependency(module("dependency"))
         checkHighlightingInAllFiles()
     }
+
+    fun testTypealiasToUnexported() = doTest {
+        module("main").addDependency(module("dependency"))
+        checkHighlightingInAllFiles()
+    }
 }