set up jest

node-jest-testing.md

Testing node using Jest

Install

• Install jest as a dev dependency

nmp i jest --save-dev

Set up directories

• Create a test directory in main project directory
• Create a test/fixtures directory for static content, db connection, etc
• Create a test/__mocks__ directory for mocked classes

Add to Package.json

• Add a start script in package.json

"test": "jest"

• Use env-cmd module to load tests with necessary .env variables
• Add -i or --runInBand options to run tests serially
• Add --watch to watch files for changes and rerun tests related to changed files.

"test": "env-cmd -f ./test.env jest --runInBand --watch"

• Add root property to package.json for jest config

  "test": "env-cmd -f ./test.env jest --runInBand --watch",
  "jest": {
    "testEnvironment": "node"
  }

Testing a node api with jest

• Install supertest as a dev dependency

npm install supertest --save-dev