[DataGrid] Add DataGridCssVars regression demo (#14662)

test/regressions/data-grid/DataGridCssVars.js

@@ -0,0 +1,69 @@
+/* eslint-disable @typescript-eslint/no-use-before-define */
+import * as React from 'react';
+import { DataGridPro } from '@mui/x-data-grid-pro';
+import {
+  randomCreatedDate,
+  randomTraderName,
+  randomEmail,
+  randomUpdatedDate,
+} from '@mui/x-data-grid-generator';
+import { Box, Experimental_CssVarsProvider as CssVarsProvider } from '@mui/material';
+
+export default function ControlPinnedColumns() {
+  const [pinnedColumns, setPinnedColumns] = React.useState({
+    left: ['name'],
+    right: ['dateCreated'],
+  });
+
+  const handlePinnedColumnsChange = React.useCallback(
+    (updatedPinnedColumns) => {
+      setPinnedColumns(updatedPinnedColumns);
+    },
+    [setPinnedColumns],
+  );
+
+  return (
+    <Box sx={{ height: 400, width: 400 }}>
+      <CssVarsProvider>
+        <DataGridPro
+          rows={rows}
+          hideFooter
+          columns={columns}
+          pinnedColumns={pinnedColumns}
+          onPinnedColumnsChange={handlePinnedColumnsChange}
+        />
+      </CssVarsProvider>
+    </Box>
+  );
+}
+
+const columns = [
+  { field: 'name', headerName: 'Name', width: 80, editable: true },
+  { field: 'email', headerName: 'Email', width: 150, editable: true },
+  { field: 'age', headerName: 'Age', type: 'number', editable: true },
+  {
+    field: 'dateCreated',
+    headerName: 'Date Created',
+    type: 'date',
+    width: 80,
+    editable: true,
+  },
+  {
+    field: 'lastLogin',
+    headerName: 'Last Login',
+    type: 'dateTime',
+    width: 180,
+    editable: true,
+  },
+];
+
+const rows = [
+  {
+    id: 1,
+    name: randomTraderName(),
+    email: randomEmail(),
+    age: 25,
+    dateCreated: randomCreatedDate(),
+    lastLogin: randomUpdatedDate(),
+  },
+];