chore: install jest and run the tests in CI

.github/workflows/test.yml

@@ -0,0 +1,31 @@
+---
+name: Tests
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+permissions:
+  contents: read
+
+jobs:
+  test:
+    name: Tests
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          submodules: true
+
+      - name: Install node v22
+        uses: actions/setup-node@v7
+        with:
+          node-version: 22
+
+      - name: Install modules
+        run: yarn install
+
+      - name: Run tests
+        run: yarn test

package.json

@@ -69,6 +69,7 @@
   },
   "devDependencies": {
     "@nestjs/cli": "9.5.0",
+    "@types/jest": "^29.5.14",
     "@types/node": "^18.15.11",
     "@types/passport-http": "^0.3.9",
     "@types/password": "^0.1.0",
@@ -80,7 +81,9 @@
     "eslint": "^8.36.0",
     "eslint-plugin-import": "^2.27.5",
     "husky": "^8.0.3",
+    "jest": "^29.7.0",
     "lint-staged": "^13.2.0",
+    "ts-jest": "^29.2.5",
     "ts-node": "^10.9.1",
     "typescript": "^4.9.5"
   },

src/services/mongo/pagination.spec.ts

@@ -0,0 +1,25 @@
+import Pagination from './pagination';
+
+describe('Pagination', () => {
+    it('returns everything on an unlimited endpoint when no page size is asked for', () => {
+        expect(new Pagination({}).getKey()).toBe('O:undefined-T:undefined-S:undefined');
+    });
+
+    it('caps a limited endpoint at 100 rows by default', () => {
+        expect(new Pagination({}, true).getKey()).toBe('O:undefined-T:100-S:undefined');
+    });
+
+    it('honours a requested page size up to 1000', () => {
+        expect(new Pagination({pageSize: 250}, true).getKey()).toContain('T:250');
+        expect(new Pagination({pageSize: 5000}, true).getKey()).toContain('T:1000');
+    });
+
+    it('skips whole pages of the requested size', () => {
+        expect(new Pagination({pageSize: 20, page: 3}).getKey()).toContain('T:20-S:40');
+    });
+
+    it('sorts ascending unless told otherwise', () => {
+        expect(new Pagination({sortBy: 'kills'}).getKey()).toContain('O:{"kills":"ASC"}');
+        expect(new Pagination({sortBy: 'kills', order: 'desc'}).getKey()).toContain('O:{"kills":"DESC"}');
+    });
+});