[FIR] Fix Disappeared INVALID_CHARACTERS

^KT-59996 Fixed

compiler/fir/checkers/checkers.js/src/org/jetbrains/kotlin/fir/analysis/js/checkers/JsDeclarationCheckers.kt

@@ -50,6 +50,7 @@ object JsDeclarationCheckers : DeclarationCheckers() {
 
     override val fileCheckers: Set<FirFileChecker>
         get() = setOf(
+            FirJsPackageDirectiveChecker,
             FirJsNameClashFileTopLevelDeclarationsChecker
         )
 }

compiler/fir/checkers/checkers.js/src/org/jetbrains/kotlin/fir/analysis/js/checkers/declaration/FirJsPackageDirectiveChecker.kt

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.fir.analysis.js.checkers.declaration
+
+import org.jetbrains.kotlin.KtNodeTypes
+import org.jetbrains.kotlin.config.LanguageFeature
+import org.jetbrains.kotlin.diagnostics.DiagnosticReporter
+import org.jetbrains.kotlin.diagnostics.reportOn
+import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.checkers.declaration.FirFileChecker
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
+import org.jetbrains.kotlin.fir.analysis.forEachChildOfType
+import org.jetbrains.kotlin.fir.analysis.js.checkers.sanitizeName
+import org.jetbrains.kotlin.fir.declarations.FirFile
+import org.jetbrains.kotlin.fir.packageFqName
+import org.jetbrains.kotlin.text
+
+object FirJsPackageDirectiveChecker: FirFileChecker() {
+    // inspired by FirJsNameCharsChecker.check()
+    override fun check(declaration: FirFile, context: CheckerContext, reporter: DiagnosticReporter) {
+        if (declaration.packageFqName.isRoot) return
+        if (context.languageVersionSettings.supportsFeature(LanguageFeature.JsAllowInvalidCharsIdentifiersEscaping)) return
+
+        declaration.packageDirective.source?.forEachChildOfType(setOf(KtNodeTypes.REFERENCE_EXPRESSION)) {
+            val name = it.text.toString()
+            if (sanitizeName(name) != name) {
+                reporter.reportOn(
+                    it,
+                    FirErrors.INVALID_CHARACTERS,
+                    "$name contains illegal characters",
+                    context,
+                )
+            }
+        }
+    }
+}