From a2ec2c6d56e6a35e34a4f6ff2c2f8759fc72a6d1 Mon Sep 17 00:00:00 2001
From: prateek-bruno <prateek@usebruno.com>
Date: Fri, 15 May 2026 14:40:19 +0530
Subject: [PATCH] fix: add resize listener for code mirror instances (#7889)

---
 .../src/components/CodeEditor/index.js        |  4 ++
 .../RequestPane/QueryEditor/index.js          |  3 ++
 .../bruno-app/src/utils/codemirror/resize.js  | 38 +++++++++++++++++++
 3 files changed, 45 insertions(+)
 create mode 100644 packages/bruno-app/src/utils/codemirror/resize.js

diff --git a/packages/bruno-app/src/components/CodeEditor/index.js b/packages/bruno-app/src/components/CodeEditor/index.js
index fcb55fbd8..38cb1ace5 100644
--- a/packages/bruno-app/src/components/CodeEditor/index.js
+++ b/packages/bruno-app/src/components/CodeEditor/index.js
@@ -16,6 +16,7 @@ import stripJsonComments from 'strip-json-comments';
 import { getAllVariables } from 'utils/collections';
 import { setupLinkAware } from 'utils/codemirror/linkAware';
 import { setupLintErrorTooltip } from 'utils/codemirror/lint-errors';
+import { setupCodeMirrorResizeRefresh } from 'utils/codemirror/resize';
 import CodeMirrorSearch from 'components/CodeMirrorSearch/index';
 import {
   applyEditorState,
@@ -269,6 +270,8 @@ class CodeEditor extends React.Component {
       if (cmInput) {
         cmInput.classList.add('mousetrap');
       }
+
+      this.cleanupResizeRefresh = setupCodeMirrorResizeRefresh(editor, this._node);
     }
   }
 
@@ -402,6 +405,7 @@ class CodeEditor extends React.Component {
 
       // Clean up lint error tooltip
       this.cleanupLintErrorTooltip?.();
+      this.cleanupResizeRefresh?.();
 
       const wrapper = this.editor.getWrapperElement();
       wrapper?.parentNode?.removeChild(wrapper);
diff --git a/packages/bruno-app/src/components/RequestPane/QueryEditor/index.js b/packages/bruno-app/src/components/RequestPane/QueryEditor/index.js
index b3a174bac..57c698bd4 100644
--- a/packages/bruno-app/src/components/RequestPane/QueryEditor/index.js
+++ b/packages/bruno-app/src/components/RequestPane/QueryEditor/index.js
@@ -16,6 +16,7 @@ import toast from 'react-hot-toast';
 import StyledWrapper from './StyledWrapper';
 import onHasCompletion from './onHasCompletion';
 import { setupLinkAware } from 'utils/codemirror/linkAware';
+import { setupCodeMirrorResizeRefresh } from 'utils/codemirror/resize';
 
 const CodeMirror = require('codemirror');
 
@@ -149,6 +150,7 @@ export default class QueryEditor extends React.Component {
     this.addOverlay();
 
     setupLinkAware(editor);
+    this.cleanupResizeRefresh = setupCodeMirrorResizeRefresh(editor, this._node);
 
     // Add mousetrap class so Mousetrap captures shortcuts even when CodeMirror is focused
     const cmInput = editor.getInputField();
@@ -192,6 +194,7 @@ export default class QueryEditor extends React.Component {
       if (this.editor?._destroyLinkAware) {
         this.editor._destroyLinkAware();
       }
+      this.cleanupResizeRefresh?.();
       this.editor.off('change', this._onEdit);
       this.editor.off('keyup', this._onKeyUp);
       this.editor.off('hasCompletion', this._onHasCompletion);
diff --git a/packages/bruno-app/src/utils/codemirror/resize.js b/packages/bruno-app/src/utils/codemirror/resize.js
new file mode 100644
index 000000000..dc43173f6
--- /dev/null
+++ b/packages/bruno-app/src/utils/codemirror/resize.js
@@ -0,0 +1,38 @@
+/**
+ * Refreshes a CodeMirror editor when its container size changes.
+ * CodeMirror measures its DOM during refresh(), so resize callbacks are
+ * coalesced into a single animation frame to avoid repeated layout work.
+ *
+ * @param {Object} editor - CodeMirror editor instance
+ * @param {HTMLElement} element - Element whose size changes should refresh the editor
+ * @returns {Function} Cleanup function
+ */
+export const setupCodeMirrorResizeRefresh = (editor, element) => {
+  if (!editor || !element || typeof ResizeObserver === 'undefined') {
+    return () => {};
+  }
+
+  let resizeRefreshFrameId = null;
+
+  const resizeObserver = new ResizeObserver(() => {
+    if (resizeRefreshFrameId) {
+      cancelAnimationFrame(resizeRefreshFrameId);
+    }
+
+    resizeRefreshFrameId = requestAnimationFrame(() => {
+      editor.refresh?.();
+      resizeRefreshFrameId = null;
+    });
+  });
+
+  resizeObserver.observe(element);
+
+  return () => {
+    resizeObserver.disconnect();
+
+    if (resizeRefreshFrameId) {
+      cancelAnimationFrame(resizeRefreshFrameId);
+      resizeRefreshFrameId = null;
+    }
+  };
+};