feat: default Jest testing configuration

.github/workflows/jest-testing.yml

@@ -0,0 +1,35 @@
+name: Run Jest testing suite
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - development
+  pull_request:
+
+env:
+  NODE_ENV: "test"
+
+jobs:
+  testing:
+    permissions: write-all
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '20.10.0'
+      - uses: actions/checkout@master
+        with:
+          fetch-depth: 0
+      - name: Build & Run test suite
+        run: |
+          yarn
+          yarn test | tee ./coverage.txt && exit ${PIPESTATUS[0]}
+      - name: Jest Coverage Comment
+        # Ensures this step is run even on previous step failure (e.g. test failed)
+        if: always()
+        uses: MishaKav/jest-coverage-comment@main
+        with:
+          coverage-summary-path: coverage/coverage-summary.json
+          junitxml-path: junit.xml
+          junitxml-title: JUnit
+          coverage-path: ./coverage.txt

.gitignore

@@ -7,4 +7,6 @@ node_modules
 .pnp.cjs
 .pnp.loader.mjs
 .env
-static/dist
+static/dist
+coverage
+junit.xml

jest.config.ts

@@ -0,0 +1,12 @@
+import { JestConfigWithTsJest } from "ts-jest";
+
+module.exports = {
+  preset: "ts-jest",
+  testEnvironment: "node",
+  roots: ["./tests"],
+  coveragePathIgnorePatterns: ["node_modules", "mocks"],
+  collectCoverage: true,
+  coverageReporters: ["json", "lcov", "text", "clover", "json-summary"],
+  reporters: ["default", "jest-junit"],
+  coverageDirectory: "coverage",
+} as JestConfigWithTsJest;

package.json

@@ -17,7 +17,8 @@
     "format:cspell": "cspell **/*",
     "knip": "knip",
     "knip-ci": "knip --no-exit-code --reporter json",
-    "prepare": "husky install"
+    "prepare": "husky install",
+    "test": "jest --setupFiles dotenv/config --coverage"
   },
   "keywords": [
     "typescript",
@@ -35,6 +36,8 @@
     "@cspell/dict-node": "^4.0.3",
     "@cspell/dict-software-terms": "^3.3.18",
     "@cspell/dict-typescript": "^3.1.2",
+    "@mswjs/data": "0.16.1",
+    "@types/jest": "29.5.12",
     "@types/node": "^20.11.19",
     "@typescript-eslint/eslint-plugin": "^7.0.1",
     "@typescript-eslint/parser": "^7.0.1",
@@ -45,10 +48,14 @@
     "eslint-plugin-prettier": "^5.1.3",
     "eslint-plugin-sonarjs": "^0.24.0",
     "husky": "^9.0.11",
+    "jest": "29.7.0",
+    "jest-junit": "16.0.0",
     "knip": "^5.0.1",
     "lint-staged": "^15.2.2",
     "npm-run-all": "^4.1.5",
     "prettier": "^3.2.5",
+    "ts-jest": "29.1.2",
+    "ts-node": "10.9.2",
     "tsx": "^4.7.1",
     "typescript": "^5.3.3"
   },

tests/__mocks__/db.ts

@@ -0,0 +1,11 @@
+import { factory, primaryKey } from "@mswjs/data";
+
+/**
+ * Creates an object that can be used as a db to persist data within tests
+ */
+export const db = factory({
+  users: {
+    id: primaryKey(Number),
+    name: String,
+  },
+});

tests/__mocks__/handlers.ts

@@ -0,0 +1,11 @@
+import { http, HttpResponse } from "msw";
+import { db } from "./db";
+
+/**
+ * Intercepts the routes and returns a custom payload
+ */
+export const handlers = [
+  http.get("https://api.ubiquity.com/users", () => {
+    return HttpResponse.json(db.users.getAll());
+  }),
+];

tests/__mocks__/node.ts

@@ -0,0 +1,4 @@
+import { setupServer } from "msw/node";
+import { handlers } from "./handlers";
+
+export const server = setupServer(...handlers);

tests/__mocks__/users-get.json

@@ -0,0 +1,10 @@
+[
+  {
+    "id": 1,
+    "name": "user1"
+  },
+  {
+    "id": 2,
+    "name": "user2"
+  }
+]

tests/main.test.ts

@@ -0,0 +1,21 @@
+import { db } from "./__mocks__/db";
+import { server } from "./__mocks__/node";
+import usersGet from "./__mocks__/users-get.json";
+
+beforeAll(() => server.listen());
+afterEach(() => server.resetHandlers());
+afterAll(() => server.close());
+
+describe("User tests", () => {
+  beforeEach(() => {
+    for (const item of usersGet) {
+      db.users.create(item);
+    }
+  });
+
+  it("Should fetch all the users", async () => {
+    const res = await fetch("https://api.ubiquity.com/users");
+    const data = await res.json();
+    expect(data).toMatchObject(usersGet);
+  });
+});

tsconfig.json

@@ -104,6 +104,7 @@
 
     /* Completeness */
     // "skipDefaultLibCheck": true,                      /* Skip type checking .d.ts files that are included with TypeScript. */
-    "skipLibCheck": true /* Skip type checking all .d.ts files. */
+    "skipLibCheck": true, /* Skip type checking all .d.ts files. */
+    "resolveJsonModule": true
   }
 }