From b0f27d01b95673c9e70b2ca36bb34ed43a8badb8 Mon Sep 17 00:00:00 2001
From: shubh-bruno <shubham@usebruno.com>
Date: Wed, 14 Jan 2026 12:24:07 +0530
Subject: [PATCH] fix: env vars loading and switching using react-virtuoso
 (#6790)

* fix: environment variables fetching and switching

* chore: formatting

* fix: support active, inactive, secret vars popup

* fix: variable highlight styles

* chore: codemirror styles

* fix: show variable highlighting when editor is inactive

* fix: tab press for switching columns

* fix: environment variables loading with react-virtuoso

* fix: refactor EnvironmentVariables component for improved table rendering

* fix: update react-virtuoso to version 4.18.1

---------

Co-authored-by: shubh-bruno <shubh-bruno@shubh-brunos-MacBook-Air.local>
Co-authored-by: Sid <siddharth@usebruno.com>
---
 package-lock.json                             |  21 +-
 packages/bruno-app/package.json               |   2 +-
 .../EnvironmentVariables/index.js             | 226 ++++++++++--------
 .../EnvironmentVariables/index.js             | 217 +++++++++--------
 4 files changed, 249 insertions(+), 217 deletions(-)

diff --git a/package-lock.json b/package-lock.json
index 9fb736dff..63d03fb7c 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -24819,15 +24819,6 @@
         "react-dom": ">=16.14.0"
       }
     },
-    "node_modules/react-virtuoso": {
-      "version": "4.17.0",
-      "resolved": "https://registry.npmjs.org/react-virtuoso/-/react-virtuoso-4.17.0.tgz",
-      "integrity": "sha512-od3pi2v13v31uzn5zPXC2u3ouISFCVhjFVFch2VvS2Cx7pWA2F1aJa3XhNTN2F07M3lhfnMnsmGeH+7wZICr7w==",
-      "peerDependencies": {
-        "react": ">=16 || >=17 || >= 18 || >= 19",
-        "react-dom": ">=16 || >=17 || >= 18 || >=19"
-      }
-    },
     "node_modules/read-cache": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/read-cache/-/read-cache-1.0.0.tgz",
@@ -30084,7 +30075,7 @@
         "react-player": "^2.16.0",
         "react-redux": "^7.2.9",
         "react-tooltip": "^5.5.2",
-        "react-virtuoso": "^4.17.0",
+        "react-virtuoso": "^4.18.1",
         "sass": "^1.46.0",
         "semver": "^7.7.1",
         "shell-quote": "^1.8.3",
@@ -31525,6 +31516,16 @@
         "url": "https://opencollective.com/express"
       }
     },
+    "packages/bruno-app/node_modules/react-virtuoso": {
+      "version": "4.18.1",
+      "resolved": "https://registry.npmjs.org/react-virtuoso/-/react-virtuoso-4.18.1.tgz",
+      "integrity": "sha512-KF474cDwaSb9+SJ380xruBB4P+yGWcVkcu26HtMqYNMTYlYbrNy8vqMkE+GpAApPPufJqgOLMoWMFG/3pJMXUA==",
+      "license": "MIT",
+      "peerDependencies": {
+        "react": ">=16 || >=17 || >= 18 || >= 19",
+        "react-dom": ">=16 || >=17 || >= 18 || >=19"
+      }
+    },
     "packages/bruno-app/node_modules/semver": {
       "version": "7.7.1",
       "resolved": "https://registry.npmjs.org/semver/-/semver-7.7.1.tgz",
diff --git a/packages/bruno-app/package.json b/packages/bruno-app/package.json
index e8341a0f7..528812fa2 100644
--- a/packages/bruno-app/package.json
+++ b/packages/bruno-app/package.json
@@ -84,7 +84,7 @@
     "react-player": "^2.16.0",
     "react-redux": "^7.2.9",
     "react-tooltip": "^5.5.2",
-    "react-virtuoso": "^4.17.0",
+    "react-virtuoso": "^4.18.1",
     "sass": "^1.46.0",
     "semver": "^7.7.1",
     "shell-quote": "^1.8.3",
diff --git a/packages/bruno-app/src/components/Environments/EnvironmentSettings/EnvironmentList/EnvironmentDetails/EnvironmentVariables/index.js b/packages/bruno-app/src/components/Environments/EnvironmentSettings/EnvironmentList/EnvironmentDetails/EnvironmentVariables/index.js
index 0e10fe9b3..dee8e1e87 100644
--- a/packages/bruno-app/src/components/Environments/EnvironmentSettings/EnvironmentList/EnvironmentDetails/EnvironmentVariables/index.js
+++ b/packages/bruno-app/src/components/Environments/EnvironmentSettings/EnvironmentList/EnvironmentDetails/EnvironmentVariables/index.js
@@ -1,4 +1,5 @@
 import React, { useCallback, useRef, useMemo, useEffect } from 'react';
+import { TableVirtuoso } from 'react-virtuoso';
 import cloneDeep from 'lodash/cloneDeep';
 import { get } from 'lodash';
 import { IconTrash, IconAlertCircle, IconInfoCircle } from '@tabler/icons';
@@ -18,14 +19,28 @@ import { getGlobalEnvironmentVariables, flattenItems, isItemARequest } from 'uti
 import SensitiveFieldWarning from 'components/SensitiveFieldWarning';
 import { sensitiveFields } from './constants';
 
+const TableRow = React.memo(({ children, item }) => <tr key={item.uid} data-testid={`env-var-row-${item.name}`}>{children}</tr>, (prevProps, nextProps) => {
+  const prevUid = prevProps?.item?.uid;
+  const nextUid = nextProps?.item?.uid;
+  return prevUid === nextUid && prevProps.children === nextProps.children;
+});
+
+const MIN_H = 35 * 2; // 2 rows worth of height
+
 const EnvironmentVariables = ({ environment, setIsModified, collection }) => {
   const dispatch = useDispatch();
   const { storedTheme } = useTheme();
   const { globalEnvironments, activeGlobalEnvironmentUid } = useSelector((state) => state.globalEnvironments);
 
+  const [tableHeight, setTableHeight] = React.useState(MIN_H);
+
   const environmentsDraft = collection?.environmentsDraft;
   const hasDraftForThisEnv = environmentsDraft?.environmentUid === environment.uid;
 
+  const handleTotalHeightChanged = React.useCallback((h) => {
+    setTableHeight(h);
+  }, []);
+
   // Track environment changes for draft restoration
   const prevEnvUidRef = React.useRef(null);
   const mountedRef = React.useRef(false);
@@ -384,111 +399,114 @@ const EnvironmentVariables = ({ environment, setIsModified, collection }) => {
 
   return (
     <StyledWrapper>
-      <div className="table-container">
-        <table>
-          <thead>
-            <tr>
-              <td className="text-center"></td>
-              <td>Name</td>
-              <td>Value</td>
-              <td className="text-center">Secret</td>
-              <td></td>
-            </tr>
-          </thead>
-          <tbody>
-            {formik.values.map((variable, index) => {
-              const isLastRow = index === formik.values.length - 1;
-              const isEmptyRow = !variable.name || variable.name.trim() === '';
-              const isLastEmptyRow = isLastRow && isEmptyRow;
+      <TableVirtuoso
+        className="table-container"
+        style={{ height: tableHeight }}
+        components={{ TableRow }}
+        data={formik.values}
+        totalListHeightChanged={handleTotalHeightChanged}
+        fixedHeaderContent={() => (
+          <tr>
+            <td className="text-center"></td>
+            <td>Name</td>
+            <td>Value</td>
+            <td className="text-center">Secret</td>
+            <td></td>
+          </tr>
+        )}
+        fixedItemHeight={35}
+        computeItemKey={(index, variable) => variable.uid}
+        itemContent={(index, variable) => {
+          const isLastRow = index === formik.values.length - 1;
+          const isEmptyRow = !variable.name || variable.name.trim() === '';
+          const isLastEmptyRow = isLastRow && isEmptyRow;
 
-              return (
-                <tr key={variable.uid} data-testid={`env-var-row-${variable.name}`}>
-                  <td className="text-center">
-                    {!isLastEmptyRow && (
-                      <input
-                        type="checkbox"
-                        className="mousetrap"
-                        name={`${index}.enabled`}
-                        checked={variable.enabled}
-                        onChange={formik.handleChange}
-                      />
-                    )}
-                  </td>
-                  <td>
-                    <div className="flex items-center">
-                      <input
-                        type="text"
-                        autoComplete="off"
-                        autoCorrect="off"
-                        autoCapitalize="off"
-                        spellCheck="false"
-                        className="mousetrap"
-                        id={`${index}.name`}
-                        name={`${index}.name`}
-                        value={variable.name}
-                        placeholder={isLastEmptyRow ? 'Name' : ''}
-                        onChange={(e) => handleNameChange(index, e)}
-                        onBlur={() => handleNameBlur(index)}
-                        onKeyDown={(e) => handleNameKeyDown(index, e)}
-                      />
-                      <ErrorMessage name={`${index}.name`} index={index} />
-                    </div>
-                  </td>
-                  <td className="flex flex-row flex-nowrap items-center">
-                    <div className="overflow-hidden grow w-full relative">
-                      <MultiLineEditor
-                        theme={storedTheme}
-                        collection={_collection}
-                        name={`${index}.value`}
-                        value={variable.value}
-                        placeholder={isLastEmptyRow ? 'Value' : ''}
-                        isSecret={variable.secret}
-                        readOnly={typeof variable.value !== 'string'}
-                        onChange={(newValue) => formik.setFieldValue(`${index}.value`, newValue, true)}
-                        onSave={handleSave}
-                      />
-                    </div>
-                    {typeof variable.value !== 'string' && (
-                      <span className="ml-2 flex items-center">
-                        <IconInfoCircle id={`${variable.uid}-disabled-info-icon`} className="text-muted" size={16} />
-                        <Tooltip
-                          anchorId={`${variable.uid}-disabled-info-icon`}
-                          content="Non-string values set via scripts are read-only and can only be updated through scripts."
-                          place="top"
-                        />
-                      </span>
-                    )}
-                    {!variable.secret && hasSensitiveUsage(variable.name) && (
-                      <SensitiveFieldWarning
-                        fieldName={variable.name}
-                        warningMessage="This variable is used in sensitive fields. Mark it as a secret for security"
-                      />
-                    )}
-                  </td>
-                  <td className="text-center">
-                    {!isLastEmptyRow && (
-                      <input
-                        type="checkbox"
-                        className="mousetrap"
-                        name={`${index}.secret`}
-                        checked={variable.secret}
-                        onChange={formik.handleChange}
-                      />
-                    )}
-                  </td>
-                  <td>
-                    {!isLastEmptyRow && (
-                      <button onClick={() => handleRemoveVar(variable.uid)}>
-                        <IconTrash strokeWidth={1.5} size={18} />
-                      </button>
-                    )}
-                  </td>
-                </tr>
-              );
-            })}
-          </tbody>
-        </table>
-      </div>
+          return (
+            <>
+              <td className="text-center">
+                {!isLastEmptyRow && (
+                  <input
+                    type="checkbox"
+                    className="mousetrap"
+                    name={`${index}.enabled`}
+                    checked={variable.enabled}
+                    onChange={formik.handleChange}
+                  />
+                )}
+              </td>
+              <td>
+                <div className="flex items-center">
+                  <input
+                    type="text"
+                    autoComplete="off"
+                    autoCorrect="off"
+                    autoCapitalize="off"
+                    spellCheck="false"
+                    className="mousetrap"
+                    id={`${index}.name`}
+                    name={`${index}.name`}
+                    value={variable.name}
+                    placeholder={isLastEmptyRow ? 'Name' : ''}
+                    onChange={(e) => handleNameChange(index, e)}
+                    onBlur={() => handleNameBlur(index)}
+                    onKeyDown={(e) => handleNameKeyDown(index, e)}
+                  />
+                  <ErrorMessage name={`${index}.name`} index={index} />
+                </div>
+              </td>
+              <td className="flex flex-row flex-nowrap items-center">
+                <div className="overflow-hidden grow w-full relative">
+                  <MultiLineEditor
+                    theme={storedTheme}
+                    collection={_collection}
+                    name={`${index}.value`}
+                    value={variable.value}
+                    placeholder={isLastEmptyRow ? 'Value' : ''}
+                    isSecret={variable.secret}
+                    readOnly={typeof variable.value !== 'string'}
+                    onChange={(newValue) => formik.setFieldValue(`${index}.value`, newValue, true)}
+                    onSave={handleSave}
+                  />
+                </div>
+                {typeof variable.value !== 'string' && (
+                  <span className="ml-2 flex items-center">
+                    <IconInfoCircle id={`${variable.uid}-disabled-info-icon`} className="text-muted" size={16} />
+                    <Tooltip
+                      anchorId={`${variable.uid}-disabled-info-icon`}
+                      content="Non-string values set via scripts are read-only and can only be updated through scripts."
+                      place="top"
+                    />
+                  </span>
+                )}
+                {!variable.secret && hasSensitiveUsage(variable.name) && (
+                  <SensitiveFieldWarning
+                    fieldName={variable.name}
+                    warningMessage="This variable is used in sensitive fields. Mark it as a secret for security"
+                  />
+                )}
+              </td>
+              <td className="text-center">
+                {!isLastEmptyRow && (
+                  <input
+                    type="checkbox"
+                    className="mousetrap"
+                    name={`${index}.secret`}
+                    checked={variable.secret}
+                    onChange={formik.handleChange}
+                  />
+                )}
+              </td>
+              <td>
+                {!isLastEmptyRow && (
+                  <button onClick={() => handleRemoveVar(variable.uid)}>
+                    <IconTrash strokeWidth={1.5} size={18} />
+                  </button>
+                )}
+              </td>
+            </>
+          );
+        }}
+      />
 
       <div className="button-container">
         <div className="flex items-center">
diff --git a/packages/bruno-app/src/components/WorkspaceHome/WorkspaceEnvironments/EnvironmentList/EnvironmentDetails/EnvironmentVariables/index.js b/packages/bruno-app/src/components/WorkspaceHome/WorkspaceEnvironments/EnvironmentList/EnvironmentDetails/EnvironmentVariables/index.js
index 95ea0bae4..6e96967dc 100644
--- a/packages/bruno-app/src/components/WorkspaceHome/WorkspaceEnvironments/EnvironmentList/EnvironmentDetails/EnvironmentVariables/index.js
+++ b/packages/bruno-app/src/components/WorkspaceHome/WorkspaceEnvironments/EnvironmentList/EnvironmentDetails/EnvironmentVariables/index.js
@@ -1,4 +1,5 @@
 import React, { useCallback, useRef } from 'react';
+import { TableVirtuoso } from 'react-virtuoso';
 import cloneDeep from 'lodash/cloneDeep';
 import { IconTrash, IconAlertCircle, IconInfoCircle } from '@tabler/icons';
 import { useTheme } from 'providers/Theme';
@@ -19,6 +20,14 @@ import { Tooltip } from 'react-tooltip';
 import { getGlobalEnvironmentVariables } from 'utils/collections';
 import Button from 'ui/Button';
 
+const MIN_H = 35 * 2;
+
+const TableRow = React.memo(({ children, item }) => <tr key={item.uid} data-testid={`env-var-row-${item.name}`}>{children}</tr>, (prevProps, nextProps) => {
+  const prevUid = prevProps?.item?.uid;
+  const nextUid = nextProps?.item?.uid;
+  return prevUid === nextUid && prevProps.children === nextProps.children;
+});
+
 const EnvironmentVariables = ({ environment, setIsModified, originalEnvironmentVariables, collection }) => {
   const dispatch = useDispatch();
   const { storedTheme } = useTheme();
@@ -28,6 +37,12 @@ const EnvironmentVariables = ({ environment, setIsModified, originalEnvironmentV
 
   const hasDraftForThisEnv = globalEnvironmentDraft?.environmentUid === environment.uid;
 
+  const [tableHeight, setTableHeight] = React.useState(MIN_H);
+
+  const handleTotalHeightChanged = React.useCallback((h) => {
+    setTableHeight(h);
+  }, []);
+
   // Track environment changes for draft restoration
   const prevEnvUidRef = React.useRef(null);
   const mountedRef = React.useRef(false);
@@ -322,109 +337,107 @@ const EnvironmentVariables = ({ environment, setIsModified, originalEnvironmentV
 
   return (
     <StyledWrapper>
-      <div className="table-container">
-        <table>
-          <thead>
-            <tr>
-              <td className="text-center"></td>
-              <td>Name</td>
-              <td>Value</td>
-              <td className="text-center">Secret</td>
-              <td></td>
-            </tr>
-          </thead>
-          <tbody>
-            {formik.values.map((variable, index) => {
-              const isLastRow = index === formik.values.length - 1;
-              const isEmptyRow = !variable.name || variable.name.trim() === '';
-              const isLastEmptyRow = isLastRow && isEmptyRow;
+      <TableVirtuoso
+        className="table-container"
+        style={{ height: tableHeight }}
+        totalListHeightChanged={handleTotalHeightChanged}
+        data={formik.values}
+        fixedItemHeight={35}
+        components={{ TableRow }}
+        fixedHeaderContent={() => (
+          <tr>
+            <td className="text-center"></td>
+            <td>Name</td>
+            <td>Value</td>
+            <td className="text-center">Secret</td>
+            <td></td>
+          </tr>
+        )}
+        itemContent={(index, variable) => {
+          const isLastRow = index === formik.values.length - 1;
+          const isEmptyRow = !variable.name || variable.name.trim() === '';
+          const isLastEmptyRow = isLastRow && isEmptyRow;
 
-              return (
-                <tr key={variable.uid}>
-                  <td className="text-center">
-                    {!isLastEmptyRow && (
-                      <input
-                        type="checkbox"
-                        className="mousetrap"
-                        name={`${index}.enabled`}
-                        checked={variable.enabled}
-                        onChange={formik.handleChange}
-                      />
-                    )}
-                  </td>
-                  <td>
-                    <div className="flex items-center">
-                      <input
-                        type="text"
-                        autoComplete="off"
-                        autoCorrect="off"
-                        autoCapitalize="off"
-                        spellCheck="false"
-                        className="mousetrap"
-                        id={`${index}.name`}
-                        name={`${index}.name`}
-                        value={variable.name}
-                        placeholder={isLastEmptyRow ? 'Name' : ''}
-                        onChange={(e) => handleNameChange(index, e)}
-                        onBlur={() => handleNameBlur(index)}
-                        onKeyDown={(e) => handleNameKeyDown(index, e)}
-                      />
-                      <ErrorMessage name={`${index}.name`} index={index} />
-                    </div>
-                  </td>
-                  <td className="flex flex-row flex-nowrap items-center">
-                    <div className="overflow-hidden grow w-full relative">
-                      <MultiLineEditor
-                        theme={storedTheme}
-                        collection={_collection}
-                        name={`${index}.value`}
-                        value={variable.value}
-                        placeholder={isLastEmptyRow ? 'Value' : ''}
-                        isSecret={variable.secret}
-                        readOnly={typeof variable.value !== 'string'}
-                        onChange={(newValue) => formik.setFieldValue(`${index}.value`, newValue, true)}
-                        onSave={handleSave}
-                      />
-                    </div>
-                    {typeof variable.value !== 'string' && (
-                      <span className="ml-2 flex items-center">
-                        <IconInfoCircle
-                          id={`${variable.uid}-disabled-info-icon`}
-                          className="text-muted"
-                          size={16}
-                        />
-                        <Tooltip
-                          anchorId={`${variable.uid}-disabled-info-icon`}
-                          content="Non-string values set via scripts are read-only and can only be updated through scripts."
-                          place="top"
-                        />
-                      </span>
-                    )}
-                  </td>
-                  <td className="text-center">
-                    {!isLastEmptyRow && (
-                      <input
-                        type="checkbox"
-                        className="mousetrap"
-                        name={`${index}.secret`}
-                        checked={variable.secret}
-                        onChange={formik.handleChange}
-                      />
-                    )}
-                  </td>
-                  <td>
-                    {!isLastEmptyRow && (
-                      <button onClick={() => handleRemoveVar(variable.uid)}>
-                        <IconTrash strokeWidth={1.5} size={18} />
-                      </button>
-                    )}
-                  </td>
-                </tr>
-              );
-            })}
-          </tbody>
-        </table>
-      </div>
+          return (
+            <>
+              <td className="text-center">
+                {!isLastEmptyRow && (
+                  <input
+                    type="checkbox"
+                    className="mousetrap"
+                    name={`${index}.enabled`}
+                    checked={variable.enabled}
+                    onChange={formik.handleChange}
+                  />
+                )}
+              </td>
+              <td>
+                <div className="flex items-center">
+                  <input
+                    type="text"
+                    autoComplete="off"
+                    autoCorrect="off"
+                    autoCapitalize="off"
+                    spellCheck="false"
+                    className="mousetrap"
+                    id={`${index}.name`}
+                    name={`${index}.name`}
+                    value={variable.name}
+                    placeholder={isLastEmptyRow ? 'Name' : ''}
+                    onChange={(e) => handleNameChange(index, e)}
+                    onBlur={() => handleNameBlur(index)}
+                    onKeyDown={(e) => handleNameKeyDown(index, e)}
+                  />
+                  <ErrorMessage name={`${index}.name`} index={index} />
+                </div>
+              </td>
+              <td className="flex flex-row flex-nowrap items-center">
+                <div className="overflow-hidden grow w-full relative">
+                  <MultiLineEditor
+                    theme={storedTheme}
+                    collection={_collection}
+                    name={`${index}.value`}
+                    value={variable.value}
+                    placeholder={isLastEmptyRow ? 'Value' : ''}
+                    isSecret={variable.secret}
+                    readOnly={typeof variable.value !== 'string'}
+                    onChange={(newValue) => formik.setFieldValue(`${index}.value`, newValue, true)}
+                    onSave={handleSave}
+                  />
+                </div>
+                {typeof variable.value !== 'string' && (
+                  <span className="ml-2 flex items-center">
+                    <IconInfoCircle id={`${variable.uid}-disabled-info-icon`} className="text-muted" size={16} />
+                    <Tooltip
+                      anchorId={`${variable.uid}-disabled-info-icon`}
+                      content="Non-string values set via scripts are read-only and can only be updated through scripts."
+                      place="top"
+                    />
+                  </span>
+                )}
+              </td>
+              <td className="text-center">
+                {!isLastEmptyRow && (
+                  <input
+                    type="checkbox"
+                    className="mousetrap"
+                    name={`${index}.secret`}
+                    checked={variable.secret}
+                    onChange={formik.handleChange}
+                  />
+                )}
+              </td>
+              <td>
+                {!isLastEmptyRow && (
+                  <button onClick={() => handleRemoveVar(variable.uid)}>
+                    <IconTrash strokeWidth={1.5} size={18} />
+                  </button>
+                )}
+              </td>
+            </>
+          );
+        }}
+      />
 
       <div className="button-container mt-5">
         <div className="flex items-center gap-2">