diff --git a/.gitignore b/.gitignore
index e7aec0e..43e8b2f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,3 +9,4 @@ node_modules
 *.pdf
 /.vscode-test
 /coverage
+.DS_Store
diff --git a/server/src/server.ts b/server/src/server.ts
index 0d35d3f..600866d 100644
--- a/server/src/server.ts
+++ b/server/src/server.ts
@@ -539,7 +539,7 @@ async function validateTextDocument(textDocument: TextDocument, force: boolean)
                 let currentFile: string = '';
                 let i = result.length;
 
-                while (i-- >= 0) {
+                while (--i >= 0) {
                     let msg: InternalDiagnostic = result[i];
 
                     if (msg === null || msg === undefined || msg.parseError || !msg.hasOwnProperty('line') || msg.source === '') {