From 4ae4c1ebce96ac79027b488460146c9a2119c3cc Mon Sep 17 00:00:00 2001
From: Anand Srinivasan <66776129+eco-monk@users.noreply.github.com>
Date: Tue, 18 Apr 2023 17:01:30 +0530
Subject: [PATCH] fix: add null check (#22474)

Sentry issue #22472

Add null check to detect when a line is deleted.
e.g. upon deleting the last line.
---
 .../CodeEditor/MarkHelpers/entityMarker.ts    | 32 ++++++++++---------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/app/client/src/components/editorComponents/CodeEditor/MarkHelpers/entityMarker.ts b/app/client/src/components/editorComponents/CodeEditor/MarkHelpers/entityMarker.ts
index 95b89065c6..d89989b2c2 100644
--- a/app/client/src/components/editorComponents/CodeEditor/MarkHelpers/entityMarker.ts
+++ b/app/client/src/components/editorComponents/CodeEditor/MarkHelpers/entityMarker.ts
@@ -27,22 +27,24 @@ export const entityMarker: MarkHelper = (
 ) => {
   let markers: CodeMirror.TextMarker[] = [];
   if (from && to) {
-    markers = editor.findMarks(
-      {
-        line: from.line,
-        ch: 0,
-      },
-      {
-        line: to.line,
-        // when a line is deleted?
-        ch: editor.getLine(to.line).length - 1,
-      },
-    );
-    clearMarkers(markers);
+    const toLine = editor.getLine(to.line);
+    if (toLine) {
+      markers = editor.findMarks(
+        {
+          line: from.line,
+          ch: 0,
+        },
+        {
+          line: to.line,
+          ch: toLine.length - 1,
+        },
+      );
+      clearMarkers(markers);
 
-    editor.eachLine(from.line, to.line, (line: CodeMirror.LineHandle) => {
-      addMarksForLine(editor, line, entityNavigationData);
-    });
+      editor.eachLine(from.line, to.line, (line: CodeMirror.LineHandle) => {
+        addMarksForLine(editor, line, entityNavigationData);
+      });
+    }
   } else {
     markers = editor.getAllMarks();
     clearMarkers(markers);