Fix formatting textedit range

Author: amiralies

server/src/server.ts

@@ -398,13 +398,9 @@ function format(msg: p.RequestMessage): Array<m.Message> {
         extension === c.resiExt
       );
       if (formattedResult.kind === "success") {
-        let max = formattedResult.result.length;
         let result: p.TextEdit[] = [
           {
-            range: {
-              start: { line: 0, character: 0 },
-              end: { line: max, character: max },
-            },
+            range: utils.getSourceRange(code),
             newText: formattedResult.result,
           },
         ];

server/src/utils.ts

@@ -476,3 +476,23 @@ export let parseCompilerLogOutput = (
 
   return { done, result };
 };
+
+export let getSourceRange = (source: string): p.Range => {
+  let start = { line: 0, character: 0 };
+
+  // Calculate end position
+  let len = source.length;
+  let line = 1;
+  let colStartIndex = 0;
+
+  for (let i = 0; i < len; i++) {
+    if (source[i] === "\n") {
+      line++;
+      colStartIndex = i + 1;
+    }
+  }
+
+  let end = { line: line, character: len - colStartIndex };
+
+  return { start, end };
+};