From 68cd382d8fb59a06b253e35864e426c2150265a9 Mon Sep 17 00:00:00 2001
From: Mohamed Hegazy <mhegazy@microsoft.com>
Date: Mon, 9 Jul 2018 17:26:35 -0700
Subject: [PATCH] Check for a module sysmbol existing before calling
 getReferencedSymbolsForModule

---
 src/services/findAllReferences.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/services/findAllReferences.ts b/src/services/findAllReferences.ts
index 6bc55f54ff7..1830be27053 100644
--- a/src/services/findAllReferences.ts
+++ b/src/services/findAllReferences.ts
@@ -234,7 +234,8 @@ namespace ts.FindAllReferences.Core {
     export function getReferencedSymbolsForNode(position: number, node: Node, program: Program, sourceFiles: ReadonlyArray<SourceFile>, cancellationToken: CancellationToken, options: Options = {}, sourceFilesSet: ReadonlyMap<true> = arrayToSet(sourceFiles, f => f.fileName)): SymbolAndEntries[] | undefined {
         if (isSourceFile(node)) {
             const reference = GoToDefinition.getReferenceAtPosition(node, position, program);
-            return reference && getReferencedSymbolsForModule(program, program.getTypeChecker().getMergedSymbol(reference.file.symbol), /*excludeImportTypeOfExportEquals*/ false, sourceFiles, sourceFilesSet);
+            const moduleSymbol = reference && program.getTypeChecker().getMergedSymbol(reference.file.symbol);
+            return moduleSymbol && getReferencedSymbolsForModule(program, moduleSymbol, /*excludeImportTypeOfExportEquals*/ false, sourceFiles, sourceFilesSet);
         }
 
         if (!options.implementations) {