chore: Migrate from jest to vitest (#51)

package.json

@@ -26,28 +26,27 @@
     "build": "node postcss.js && tsc",
     "postbuild": "cp dark-mode-utils.css package.json THIRD-PARTY-LICENSES.txt LICENSE README.md lib",
     "lint": "eslint .",
-    "test": "jest --coverage"
+    "test": "vitest --run"
   },
   "devDependencies": {
     "@testing-library/jest-dom": "^5.16.1",
-    "@types/jest": "^27.4.0",
     "@typescript-eslint/eslint-plugin": "^4.33.0",
     "@typescript-eslint/parser": "^4.33.0",
+    "@vitest/coverage-istanbul": "^2.1.6",
     "eslint": "^7.32.0",
     "eslint-config-prettier": "^8.3.0",
     "eslint-plugin-header": "3.1.0",
     "eslint-plugin-prettier": "^3.4.1",
     "eslint-plugin-unicorn": "^34.0.1",
     "husky": "^9.0.11",
-    "jest": "^27.4.7",
     "lint-staged": "^13.2.1",
     "normalize.css": "^8.0.1",
     "postcss": "^8.4.31",
     "postcss-import": "^14.0.2",
     "postcss-url": "^10.1.3",
     "prettier": "^2.5.1",
-    "ts-jest": "^27.1.3",
-    "typescript": "^4.5.5"
+    "typescript": "^4.5.5",
+    "vitest": "^2.1.6"
   },
   "lint-staged": {
     "*.{ts,js}": [

src/__tests__/apply-mode.test.ts

@@ -1,5 +1,6 @@
 // Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
+import { test, expect, beforeEach, afterEach } from 'vitest';
 import { applyMode, Mode, applyDensity, Density } from '../index';
 
 let originalClassName: string;

src/__tests__/disable-motion.test.ts

@@ -1,5 +1,6 @@
 // Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
+import { test, expect, beforeEach, afterEach } from 'vitest';
 import { disableMotion } from '../index';
 
 let originalClassName: string;

src/__tests__/setup.ts

@@ -1,3 +1,6 @@
 // Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
-import '@testing-library/jest-dom/extend-expect';
+import { expect } from 'vitest';
+import * as matchers from '@testing-library/jest-dom/matchers';
+
+expect.extend(matchers);

vite.config.ts

@@ -0,0 +1,16 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+import { defineConfig } from 'vitest/config';
+
+export default defineConfig({
+  test: {
+    environment: 'jsdom',
+    setupFiles: ['./src/__tests__/setup.ts'],
+    coverage: {
+      enabled: process.env.CI === 'true',
+      provider: 'istanbul',
+      include: ['src/**'],
+      exclude: ['**/debug-tools/**', '**/test/**'],
+    },
+  },
+});