Why?

Logging to the console during tests can be a sign of:

• 🚫 warnings from third-party libraries such as React for improper usage
• 🤕 temporary code that shouldn't be checked into your project
• 📢 unnecessary spam in your tests window

This little library throws an error after each test if a console method was called during it. It's got some nifty features:

• 📊 Summary of which methods are called with calling arguments
• 🛫 Failures are thrown after tests finish, so your tests will fail normally if they should

stdout | src/index.test.ts > index > example test that console.logs
Whoops!

 ❯ src/index.test.ts (4)
   ❯ index (4)
     × example test that console.logs
       ⠙ [ afterEach ]
     ✓ example test that does not console.log

⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯- Failed Tests 1 ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯-

 FAIL  src/index.test.ts > index > example test that console.logs
Error: Oh no! Your test called the following console method:
  * log (1 call)
    > Call 0: "Whoops!"

Usage

console-fail-test is meant to support any (test framework) & (spy library) combination. It will auto-detect your combination if possible and use the most appropriate environment hooks and function spies it can find.

For example, in a Jest config:

// jest.config.js
module.exports = {
	setupFilesAfterEnv: ["console-fail-test/setup"],
};

Prior to [email protected], this was setup.cjs or setup.mjs.

Test Frameworks

See the Documentation link for each supported framework for how to set up console-fail-test with that framework.

Spy Libraries

If your test framework provides its own spy library, console-fail-test will by default use that library. If a supported spy library isn't detected, an internal fallback will be used to spy on console methods.

You can request a specific test library using the Node API with its API request:

require("console-fail-test").cft({
	spyLibrary: "sinon",
});

Ignoring console methods

By default, console-fail-test will error on any called console method. If you'd like allow certain methods, pass a console object to the cft API when you set it up:

require("console-fail-test").cft({
	console: {
		warn: true, // won't error on any instance of console.warn
	},
});

Development

See .github/CONTRIBUTING.md, then .github/DEVELOPMENT.md. Thanks! 📢

Contributors

💝 This package was templated with create-typescript-app using the Bingo framework.