Migrate testing setup from Jest to Vitest (#3261)

* Initial plan

* Replace Jest with Vitest dependencies and configuration

Co-authored-by: RichDom2185 <[email protected]>

* Update test files to use Vitest API and create working configuration

Co-authored-by: RichDom2185 <[email protected]>

* Complete Jest to Vitest migration with final configuration and documentation updates

Co-authored-by: RichDom2185 <[email protected]>

* Update lockfile

* Reformat files

* Fix test config

* Remove old jest config

* Update dependencies

* Resolve import inconsistency

* Deduplicate dependencies

* Rename test files

* Rename snapshots

* Update some test snapshots

* Update more test snapshots

* Move past fixes to test setup

* Remove unnecessary reference types

* Fix some tests

* Update remaining snapshots

* Fix more tests

* Fix navigation bar tests

* Fix some type errors

* Fix more type errors

* Update test snapshot

* Update scripts

* Fix more tests

* Reformat files

* Remove double test suffix

* Fix version

* Prevent opening browser UI on test launch

* Fail test early on CI

* Fix remaining errors

* Fix more tests and snapshots

* Fix ESLint issues

* Configure i18next for tests

* Fix coverage generation

* Remove comment

* Resolve imports

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: RichDom2185 <[email protected]>

Author: Copilot

.github/workflows/ci.yml

@@ -22,7 +22,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        commands: [tsc, 'format:ci', eslint, build, test, test-coveralls]
+        commands: [tsc, 'format:ci', eslint, build, 'test --bail=1', test-coveralls]
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
@@ -43,5 +43,5 @@ jobs:
         if: matrix.commands == 'test-coveralls'
         uses: coverallsapp/github-action@master
         with:
-          path-to-lcov: lcov.info
+          path-to-lcov: coverage/lcov.info
           github-token: ${{ secrets.GITHUB_TOKEN }}

CONTRIBUTING.md

@@ -16,10 +16,10 @@ To start contributing, create a fork from our repo and send a PR. Refer to [this
 
 The frontend comes with an extensive test suite. To run the tests after you made your modifications, run
 `yarn test`. Regression tests are run automatically when you want to push changes to this repository.
-The regression tests are generated using `jest` and stored as snapshots in `src/\_\_tests\_\_`. After modifying the frontend, carefully inspect any failing regression tests reported in red in the command line. If you are convinced that the regression tests and not your changes are at fault, you can update the regression tests by running:
+The regression tests are generated using `vitest` and stored as snapshots in `src/\_\_tests\_\_`. After modifying the frontend, carefully inspect any failing regression tests reported in red in the command line. If you are convinced that the regression tests and not your changes are at fault, you can update the regression tests by running:
 
 ```bash
-yarn test --updateSnapshot
+yarn test --update
 ```
 
 ## Manually testing the frontend

jest.config.js

@@ -21,9 +21,11 @@
     "format:scss": "prettier --list-different --parser scss \"src/**/*.scss\"",
     "format:ci": "yarn run format:tsx && yarn run format:scss",
     "start": "rsbuild dev",
-    "test": "cross-env TZ=Asia/Singapore jest",
+    "test": "cross-env TZ=Asia/Singapore vitest run",
+    "test:watch": "cross-env TZ=Asia/Singapore vitest",
+    "test:ui": "cross-env TZ=Asia/Singapore vitest --ui --no-open",
     "test-coveralls": "./scripts/test-coveralls.sh",
-    "update-ui-snapshots": "jest --updateSnapshot",
+    "update-ui-snapshots": "vitest run --update",
     "eslint": "eslint src",
     "prepare": "husky",
     "preview": "rsbuild preview"
@@ -122,7 +124,6 @@
     "@rsbuild/plugin-svgr": "^1.2.0",
     "@svgr/webpack": "^8.0.0",
     "@swc/core": "^1.11.22",
-    "@swc/jest": "^0.2.38",
     "@testing-library/dom": "^10.4.0",
     "@testing-library/jest-dom": "^6.0.0",
     "@testing-library/react": "^16.0.0",
@@ -134,7 +135,6 @@
     "@types/gapi.client.drive-v3": "^0.0.5",
     "@types/google.picker": "^0.0.51",
     "@types/identity-obj-proxy": "^3",
-    "@types/jest": "^29.0.0",
     "@types/js-cookie": "^3.0.6",
     "@types/js-yaml": "^4.0.5",
     "@types/lodash": "^4.14.195",
@@ -147,7 +147,9 @@
     "@types/redux-mock-store": "^1.0.3",
     "@types/showdown": "^2.0.1",
     "@types/xml2js": "^0.4.11",
-    "babel-jest": "^29.7.0",
+    "@vitejs/plugin-react-swc": "^3.11.0",
+    "@vitest/coverage-v8": "3.2.4",
+    "@vitest/ui": "^3.2.4",
     "buffer": "^6.0.3",
     "canvas": "^3.1.0",
     "constants-browserify": "^1.0.0",
@@ -161,8 +163,7 @@
     "https-browserify": "^1.0.0",
     "husky": "^9.0.0",
     "identity-obj-proxy": "^3.0.0",
-    "jest": "^29.7.0",
-    "jest-environment-jsdom": "^29.7.0",
+    "jsdom": "^25.0.1",
     "npm-run-all2": "^8.0.0",
     "os-browserify": "^0.3.0",
     "path": "^0.12.7",
@@ -181,6 +182,7 @@
     "typescript": "^5.8.2",
     "typescript-eslint": "^8.1.0",
     "url": "^0.11.1",
+    "vitest": "^3.2.4",
     "webpack-bundle-analyzer": "^4.9.0"
   },
   "browserslist": {

jsdom-env.js

@@ -1,10 +1,10 @@
+import { InjectManifest } from '@aaroon/workbox-rspack-plugin';
 import { defineConfig, loadEnv } from '@rsbuild/core';
 import { pluginEslint } from '@rsbuild/plugin-eslint';
 import { pluginNodePolyfill } from '@rsbuild/plugin-node-polyfill';
 import { pluginReact } from '@rsbuild/plugin-react';
 import { pluginSass } from '@rsbuild/plugin-sass';
 import { pluginSvgr } from '@rsbuild/plugin-svgr';
-import { InjectManifest } from '@aaroon/workbox-rspack-plugin';
 
 const { publicVars, rawPublicVars } = loadEnv({ prefixes: ['REACT_APP_'] });
 
@@ -91,13 +91,15 @@ export default defineConfig({
         (warning: any) => {
           // Ignore the warnings that occur because js-slang uses dynamic imports
           // to load Source modules
-          const moduleName = warning.moduleDescriptor?.name
-          if (!moduleName) return false
+          const moduleName = warning.moduleDescriptor?.name;
+          if (!moduleName) return false;
 
-          if (!/js-slang\/dist\/modules\/loader\/loaders.js/.test(moduleName)) return false
-          return /Critical dependency: the request of a dependency is an expression/.test(warning.message)
+          if (!/js-slang\/dist\/modules\/loader\/loaders.js/.test(moduleName)) return false;
+          return /Critical dependency: the request of a dependency is an expression/.test(
+            warning.message
+          );
         }
-        
+
         // {
         //   // Ignore warnings for dependencies that do not ship with a source map.
         //   // This is because we cannot do anything about our dependencies.
@@ -124,7 +126,7 @@ export default defineConfig({
         new InjectManifest({
           swSrc: './src/service-worker.ts',
           swDest: 'service-worker.js',
-          maximumFileSizeToCacheInBytes: 20 * 1024 * 1024,
+          maximumFileSizeToCacheInBytes: 20 * 1024 * 1024
         })
       ];
 

package.json

@@ -3,5 +3,5 @@
 set -euo pipefail
 
 ./scripts/coverage-fix.sh do && \
-  yarn test --coverage --coverageReporters=text-lcov \
-    --collectCoverageFrom='!**/src/features/game/**' > lcov.info
+  yarn test --coverage --coverage.reporter=lcov \
+    --coverage.exclude='**/src/features/game/**'

rsbuild.config.ts

@@ -1,4 +1,4 @@
-// Jest Snapshot v1, https://goo.gl/fbAQLP
+// Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
 
 exports[`ContentDisplay page renders correctly 1`] = `
 <div