Loads of unit tests and CI

.github/workflows/ci.yml

@@ -0,0 +1,37 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+      - "*/*"
+
+jobs:
+  lint_and_test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "20.x"
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Lint
+        run: npm run lint
+
+      - name: Run tests
+        run: npm test
+
+      - name: Run snapshot tests
+        run: npm test -- -u
+
+      - name: Check formatting
+        run: npx prettier --check "./**/*.{ts,tsx}"

.gitignore

@@ -5,6 +5,7 @@
 /.pnp
 .pnp.js
 .yarn/install-state.gz
+.swc
 
 # testing
 /coverage

jest.config.ts

@@ -0,0 +1,18 @@
+import type { Config } from "jest";
+import nextJest from "next/jest.js";
+
+const createJestConfig = nextJest({
+  // Provide the path to your Next.js app to load next.config.js and .env files in your test environment
+  dir: "./",
+});
+
+// Add any custom config to be passed to Jest
+const config: Config = {
+  coverageProvider: "v8",
+  testEnvironment: "jsdom",
+  // Add more setup options before each test is run
+  // setupFilesAfterEnv: ['<rootDir>/jest.setup.ts'],
+};
+
+// createJestConfig is exported this way to ensure that next/jest can load the Next.js config which is async
+export default createJestConfig(config);