Fix formatting bug

Author: vetlek

server/src/documentProvider.ts

@@ -29,7 +29,6 @@ class Document implements ITextDocument {
 
     readonly uri: string;
     readonly version: number = 0;
-    readonly lineCount: number = 0;
 
     constructor(uri: string, init: { inMemoryDoc: ITextDocument });
     constructor(uri: string, init: { onDiskDoc: ITextDocument });
@@ -96,6 +95,18 @@ class Document implements ITextDocument {
     setOnDiskDoc(doc: TextDocument | undefined) {
         this.onDiskDoc = doc;
     }
+
+    get lineCount(): number {
+        if (this.inMemoryDoc) {
+            return this.inMemoryDoc.lineCount;
+        }
+
+        if (this.onDiskDoc) {
+            return this.onDiskDoc.lineCount;
+        }
+
+        throw new Error("Document has been closed");
+    }
 }
 
 export class DocumentProvider {