Add utitlity for stringContains

src/compiler/resolutionCache.ts

@@ -324,7 +324,7 @@ namespace ts {
             let dirPath = getDirectoryPath(failedLookupLocationPath);
 
             // If directory path contains node module, get the most parent node_modules directory for watching
-            while (dirPath.indexOf("/node_modules/") !== -1) {
+            while (stringContains(dirPath, "/node_modules/")) {
                 dir = getDirectoryPath(dir);
                 dirPath = getDirectoryPath(dirPath);
             }
@@ -334,7 +334,6 @@ namespace ts {
                 return { dir, dirPath };
             }
 
-
             // Use some ancestor of the root directory
             if (rootPath !== undefined) {
                 while (!isInDirectoryPath(dirPath, rootPath)) {