code · pull · Mar 23, 2026 · Mar 23, 2026
diff --git a/src/DataGrid.tsx b/src/DataGrid.tsx
@@ -29,8 +29,7 @@ import {
   isCtrlKeyHeldDown,
   isDefaultCellInput,
   renderMeasuringCells,
-  scrollIntoView,
-  sign
+  scrollIntoView
 } from './utils';
 import type {
   CalculatedColumn,
@@ -573,8 +572,10 @@ export function DataGrid<R, SR = unknown, K extends Key = Key>(props: DataGridPr
       previousRowIdx !== rowIdx &&
       previousRowIdx < rows.length
     ) {
-      const step = sign(rowIdx - previousRowIdx);
-      for (let i = previousRowIdx + step; i < rowIdx; i += step) {
+      const [min, max] =
+        previousRowIdx < rowIdx ? [previousRowIdx, rowIdx] : [rowIdx, previousRowIdx];
+
+      for (let i = min + 1; i < max; i++) {
         const row = rows[i];
         if (isRowSelectionDisabled?.(row) === true) continue;
         if (checked) {

diff --git a/src/utils/index.ts b/src/utils/index.ts
@@ -8,7 +8,7 @@ export * from './keyboardUtils';
 export * from './renderMeasuringCells';
 export * from './styleUtils';
 
-export const { min, max, floor, sign, abs } = Math;
+export const { min, max, floor, abs } = Math;
 
 export function assertIsValidKeyGetter<R, K extends React.Key>(
   keyGetter: Maybe<(row: NoInfer<R>) => K>

diff --git a/test/browser/column/resizable.test.tsx b/test/browser/column/resizable.test.tsx
@@ -1,5 +1,5 @@
 import { useState } from 'react';
-import { commands, page, userEvent } from 'vitest/browser';
+import { commands, page, server, userEvent } from 'vitest/browser';
 
 import { DataGrid, type Column, type ColumnWidth, type ColumnWidths } from '../../../src';
 import { setup } from '../utils';
@@ -313,11 +313,8 @@ test('should use columnWidths and onColumnWidthsChange props when provided', asy
 });
 
 async function testGridTemplateColumns(chrome: string, firefox: string, firefoxCI = firefox) {
-  const gridTemplateColumns = navigator.userAgent.includes('Chrome')
-    ? chrome
-    : __IS_CI__
-      ? firefoxCI
-      : firefox;
+  const gridTemplateColumns =
+    server.browser === 'chromium' ? chrome : import.meta.env.CI ? firefoxCI : firefox;
 
   await expect.element(grid).toHaveStyle({ gridTemplateColumns });
 }
diff --git a/test/browser/rowSelection.test.tsx b/test/browser/rowSelection.test.tsx
@@ -239,16 +239,34 @@ test('extra keys are preserved when updating the selectedRows Set', async () =>
 
 test('select/deselect rows using shift click', async () => {
   await setup();
+
+  // forward selection
   await toggleSelection(0);
   await toggleSelection(2, true);
   await testSelection(0, true);
   await testSelection(1, true);
   await testSelection(2, true);
+
+  // forward deselection
   await toggleSelection(0);
   await toggleSelection(2, true);
   await testSelection(0, false);
   await testSelection(1, false);
   await testSelection(2, false);
+
+  // backward selection
+  await toggleSelection(2);
+  await toggleSelection(0, true);
+  await testSelection(0, true);
+  await testSelection(1, true);
+  await testSelection(2, true);
+
+  // backward deselection
+  await toggleSelection(2);
+  await toggleSelection(0, true);
+  await testSelection(0, false);
+  await testSelection(1, false);
+  await testSelection(2, false);
 });
 
 test('select rows using shift space', async () => {

diff --git a/test/browser/virtualization.test.ts b/test/browser/virtualization.test.ts
@@ -220,18 +220,29 @@ test('zero rows', async () => {
   await expect.element(rows).toHaveLength(0);
 });
 
-test('virtualization is enable with not enough columns or rows to virtualize', async () => {
+test('virtualization is enabled with not enough columns or rows to virtualize', async () => {
   await setupGrid(true, 5, 5);
 
   await assertHeaderCells(5, 0, 4);
   await assertRows(5, 0, 4);
   await expect.element(cells).toHaveLength(5 * 5);
 });
 
-test('enableVirtualization is disabled', async () => {
+test('virtualization is disabled with no frozen columns', async () => {
   await setupGrid(false, 40, 100);
 
   await assertHeaderCells(40, 0, 39);
   await assertRows(100, 0, 99);
   await expect.element(cells).toHaveLength(40 * 100);
 });
+
+// failing test
+// cannot use `test.fails` as console logs lead to timeout in parallel tests
+// https://github.com/vitest-dev/vitest/issues/9941
+test.skip('virtualization is disabled with some frozen columns', async () => {
+  await setupGrid(false, 40, 100, 3);
+
+  await assertHeaderCells(40, 0, 39);
+  await assertRows(100, 0, 99);
+  await expect.element(cells).toHaveLength(40 * 100);
+});
diff --git a/test/failOnConsole.ts b/test/failOnConsole.ts
@@ -1,37 +1,37 @@
-let consoleErrorOrConsoleWarnWereCalled = false;
+beforeEach(({ onTestFinished }) => {
+  vi.spyOn(console, 'warn').mockName('console.warn');
 
-beforeAll(() => {
-  console.error = (...params) => {
+  // use split mocks to not increase the calls count when ignoring undesired logs
+  const errorMock = vi.fn(console.error).mockName('console.error');
+  vi.spyOn(console, 'error').mockImplementation(function error(...params) {
+    // https://github.com/vitest-dev/vitest/blob/0685b6f027576589464fc6109ddc071ef0079f16/packages/browser/src/client/public/error-catcher.js#L34-L38
+    // https://github.com/vitest-dev/vitest/blob/0685b6f027576589464fc6109ddc071ef0079f16/test/browser/fixtures/unhandled-non-error/basic.test.ts
     if (
       params[0] instanceof Error &&
       params[0].message === 'ResizeObserver loop completed with undelivered notifications.'
     ) {
       return;
     }
 
-    consoleErrorOrConsoleWarnWereCalled = true;
-    console.log(...params);
-  };
-
-  console.warn = (...params) => {
-    consoleErrorOrConsoleWarnWereCalled = true;
-    console.log(...params);
-  };
-});
+    return errorMock(...params);
+  });
 
-afterEach(() => {
   // Wait for the test and all `afterEach` hooks to complete to ensure all logs are caught
-  onTestFinished(({ task, signal }) => {
+  onTestFinished(({ expect, task, signal }) => {
     // avoid failing test runs twice
-    if (task.result!.state !== 'fail' && !signal.aborted) {
-      expect
-        .soft(
-          consoleErrorOrConsoleWarnWereCalled,
-          'errors/warnings were logged to the console during the test'
-        )
-        .toBe(false);
-    }
+    if (task.result?.state === 'fail' || signal.aborted) return;
 
-    consoleErrorOrConsoleWarnWereCalled = false;
+    expect
+      .soft(
+        console.warn,
+        'console.warn() was called during the test; please resolve unexpected warnings'
+      )
+      .toHaveBeenCalledTimes(0);
+    expect
+      .soft(
+        errorMock,
+        'console.error() was called during the test; please resolve unexpected errors'
+      )
+      .toHaveBeenCalledTimes(0);
   });
 });
diff --git a/test/globals.d.ts b/test/globals.d.ts
@@ -1,5 +1,9 @@
 declare global {
-  const __IS_CI__: boolean;
+  interface ImportMeta {
+    readonly env: {
+      readonly CI: boolean;
+    };
+  }
 }
 
 declare module 'vitest/browser' {

diff --git a/vite.config.ts b/vite.config.ts
@@ -3,10 +3,10 @@ import react from '@vitejs/plugin-react';
 import { playwright, type PlaywrightProviderOptions } from '@vitest/browser-playwright';
 import { ecij } from 'ecij/plugin';
 import { defineConfig, type ViteUserConfig } from 'vitest/config';
-import type { BrowserCommand, BrowserInstanceOption } from 'vitest/node';
+import type { BrowserCommand } from 'vitest/node';
 
 const isCI = process.env.CI === 'true';
-const isTest = process.env.NODE_ENV === 'test';
+const isTest = process.env.VITEST === 'true';
 
 // TODO: remove when `userEvent.pointer` is supported
 const resizeColumn: BrowserCommand<[name: string, resizeBy: number | readonly number[]]> = async (
@@ -48,59 +48,42 @@ const playwrightOptions: PlaywrightProviderOptions = {
   }
 };
 
-// vitest modifies the instance objects, so we cannot rely on static objects
-// https://github.com/vitest-dev/vitest/issues/9877
-function getInstances(): BrowserInstanceOption[] {
-  return [
-    {
-      browser: 'chromium',
-      provider: playwright({
-        ...playwrightOptions,
-        launchOptions: {
-          channel: 'chromium'
-        }
-      })
-    },
-    {
-      browser: 'firefox',
-      provider: playwright(playwrightOptions),
-      // TODO: remove when FF tests are stable
-      fileParallelism: false
-    }
-  ];
-}
-
 export default defineConfig(
   ({ isPreview }): ViteUserConfig => ({
     base: '/react-data-grid/',
     cacheDir: '.cache/vite',
     clearScreen: false,
-    define: isTest ? { __IS_CI__: JSON.stringify(isCI) } : {},
     build: {
       modulePreload: { polyfill: false },
       sourcemap: true,
       reportCompressedSize: false,
       // https://github.com/parcel-bundler/lightningcss/issues/873
       cssTarget: 'esnext'
     },
-    plugins: [
-      ecij(),
-      (!isTest || isPreview) &&
-        tanstackRouter({
-          target: 'react',
-          generatedRouteTree: 'website/routeTree.gen.ts',
-          routesDirectory: 'website/routes',
-          autoCodeSplitting: true
-        }),
-      react()
-    ],
+    plugins: isPreview
+      ? []
+      : [
+          ecij(),
+          !isTest &&
+            tanstackRouter({
+              target: 'react',
+              generatedRouteTree: 'website/routeTree.gen.ts',
+              routesDirectory: 'website/routes',
+              autoCodeSplitting: true
+            }),
+          react()
+        ],
     server: {
       open: true
     },
     test: {
       dir: 'test',
       globals: true,
       printConsoleTrace: true,
+      env: {
+        // @ts-expect-error
+        CI: isCI
+      },
       coverage: {
         provider: 'istanbul',
         enabled: isCI,
@@ -120,20 +103,51 @@ export default defineConfig(
         }
       },
       slowTestThreshold: 1000,
+      browser: {
+        headless: true,
+        ui: false,
+        viewport,
+        commands: { resizeColumn, dragFill },
+        expect: {
+          toMatchScreenshot: {
+            resolveScreenshotPath({
+              root,
+              testFileDirectory,
+              testFileName,
+              arg,
+              browserName,
+              platform,
+              ext
+            }) {
+              return `${root}/${testFileDirectory}/screenshots/${testFileName}/${arg}-${browserName}-${platform}${ext}`;
+            }
+          }
+        },
+        instances: [
+          {
+            browser: 'chromium',
+            provider: playwright({
+              ...playwrightOptions,
+              launchOptions: {
+                channel: 'chromium'
+              }
+            })
+          },
+          {
+            browser: 'firefox',
+            provider: playwright(playwrightOptions),
+            // TODO: remove when FF tests are stable
+            fileParallelism: false
+          }
+        ]
+      },
       projects: [
         {
           extends: true,
           test: {
             name: 'browser',
             include: ['browser/**/*.test.*'],
-            browser: {
-              enabled: true,
-              instances: getInstances(),
-              commands: { resizeColumn, dragFill },
-              viewport,
-              headless: true,
-              ui: false
-            },
+            browser: { enabled: true },
             setupFiles: ['test/browser/styles.css', 'test/setupBrowser.ts', 'test/failOnConsole.ts']
           }
         },
@@ -142,28 +156,7 @@ export default defineConfig(
           test: {
             name: 'visual',
             include: ['visual/*.test.*'],
-            browser: {
-              enabled: true,
-              instances: getInstances(),
-              viewport,
-              headless: true,
-              ui: false,
-              expect: {
-                toMatchScreenshot: {
-                  resolveScreenshotPath({
-                    root,
-                    testFileDirectory,
-                    testFileName,
-                    arg,
-                    browserName,
-                    platform,
-                    ext
-                  }) {
-                    return `${root}/${testFileDirectory}/screenshots/${testFileName}/${arg}-${browserName}-${platform}${ext}`;
-                  }
-                }
-              }
-            },
+            browser: { enabled: true },
             setupFiles: ['test/setupBrowser.ts', 'test/failOnConsole.ts']
           }
         },