Node.js：Jest测试框架

npm install -D jest babel-jest babel-core babel-preset-env regenerator-runtime

{
  "type": "module",
  "scripts": {
    "test": "jest --verbose"
  },
  "devDependencies": {
    "babel-core": "^6.26.3",
    "babel-jest": "^28.1.3",
    "babel-preset-env": "^1.7.0",
    "jest": "^28.1.3",
    "regenerator-runtime": "^0.13.9"
  }
}

{
  "presets": ["env"]
}

export default {
  sum(a, b) {
    return a + b
  },
}

import functions from '../src/functions'
test('sum(2 + 2) 等于 4', () => {
  expect(functions.sum(2, 2)).toBe(4)
})

$ npx jest
 PASS  tests/functions.test.js
  ✓ sum(2 + 2) 等于 4 (1 ms)
Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        1.141 s
Ran all test suites.