From 0f12731c43a97bf1eb689ffd7959eb88b8437eaf Mon Sep 17 00:00:00 2001
From: Bill Ticehurst <billti@hotmail.com>
Date: Tue, 21 Mar 2017 14:49:20 -0700
Subject: [PATCH] Suppress semantic errors in JS only configured projects

---
 src/server/session.ts | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/server/session.ts b/src/server/session.ts
index 3732dae655b..3330fd4f8c9 100644
--- a/src/server/session.ts
+++ b/src/server/session.ts
@@ -14,8 +14,14 @@ namespace ts.server {
         return ((1e9 * seconds) + nanoseconds) / 1000000.0;
     }
 
-    function shouldSkipSematicCheck(project: Project) {
-        return (project.projectKind === ProjectKind.Inferred || project.projectKind === ProjectKind.External) && project.isJsOnlyProject();
+    function shouldSkipSemanticCheck(project: Project) {
+        if (project.projectKind === ProjectKind.Inferred || project.projectKind === ProjectKind.External) {
+            return project.isJsOnlyProject();
+        }
+        else {
+            // For configured projects, require that skipLibCheck be set also
+            return project.getCompilerOptions().skipLibCheck && project.isJsOnlyProject();
+        }
     }
 
     interface FileStart {
@@ -278,7 +284,7 @@ namespace ts.server {
         private semanticCheck(file: NormalizedPath, project: Project) {
             try {
                 let diags: Diagnostic[] = [];
-                if (!shouldSkipSematicCheck(project)) {
+                if (!shouldSkipSemanticCheck(project)) {
                     diags = project.getLanguageService().getSemanticDiagnostics(file);
                 }
 
@@ -396,7 +402,7 @@ namespace ts.server {
 
         private getDiagnosticsWorker(args: protocol.FileRequestArgs, isSemantic: boolean, selector: (project: Project, file: string) => Diagnostic[], includeLinePosition: boolean) {
             const { project, file } = this.getFileAndProject(args);
-            if (isSemantic && shouldSkipSematicCheck(project)) {
+            if (isSemantic && shouldSkipSemanticCheck(project)) {
                 return [];
             }
             const scriptInfo = project.getScriptInfoForNormalizedPath(file);