From 73881203867cfd8bf3e371b42f2282f0b0554a01 Mon Sep 17 00:00:00 2001
From: Cyrus Najmabadi <cyrusn@microsoft.com>
Date: Mon, 23 Mar 2015 19:02:46 -0700
Subject: [PATCH] Fix issue where getSemanticDiagnostics was returning
 undefined on a .d.ts file.

---
 src/services/services.ts                                 | 2 +-
 .../fourslash/getSemanticDiagnosticForDeclaration1.ts    | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)
 create mode 100644 tests/cases/fourslash/getSemanticDiagnosticForDeclaration1.ts

diff --git a/src/services/services.ts b/src/services/services.ts
index 5ff7c578aa0ba..ba8b8c00b7d17 100644
--- a/src/services/services.ts
+++ b/src/services/services.ts
@@ -2389,7 +2389,7 @@ module ts {
 
             // If '-d' is enabled, check for emitter error. One example of emitter error is export class implements non-export interface
             let declarationDiagnostics = program.getDeclarationDiagnostics(targetSourceFile);
-            return semanticDiagnostics.concat(declarationDiagnostics);
+            return concatenate(semanticDiagnostics, declarationDiagnostics);
         }
 
         function getCompilerOptionsDiagnostics() {
diff --git a/tests/cases/fourslash/getSemanticDiagnosticForDeclaration1.ts b/tests/cases/fourslash/getSemanticDiagnosticForDeclaration1.ts
new file mode 100644
index 0000000000000..13a2dccfd26da
--- /dev/null
+++ b/tests/cases/fourslash/getSemanticDiagnosticForDeclaration1.ts
@@ -0,0 +1,9 @@
+/// <reference path="fourslash.ts" />
+
+// @declaration: true
+// @Filename: File.d.ts
+//// declare var v: string;
+
+verify.numberOfErrorsInCurrentFile(0);
+
+