KnowDev Jest Extensions 🃏

📋 Usage

npm install --save @knowdev/jest

jest.config.js

module.exports = {
  setupFilesAfterEnv: ["jest-extended", "@knowdev/jest"],
};

📖 Reference

toBeAsyncIterator()

Checks that a special symbol, subject[Symbol.asyncIterator], exists and is a function. Does not exercise iterator

expect(subject).toBeAsyncIterator();

toBeClass()

Attempts to instantiate subject

expect(subject).toBeClass();

toBeCalledWithInitialParams()

Unlike toHaveBeenCalledWith(), which matches the entire set of parameters, toBeCalledWithInitialParams() only matches the first n parameters. E.g., if you want to test only the first parameter

# Passes:
mockFunction(1, 2, 3);
expect(mockFunction).toBeCalledWithInitialParams(1, 2);

# Fails:
mockFunction(1);
expect(mockFunction).toBeCalledWithInitialParams(1, 2);

toThrowProjectError(), toThrowProjectErrorAsync()

Checks that the thrown error is an instance of ProjectError. Can be called with any of the following matchers, which much all match:

String (matches as a substring)
RegExp
ProjectError class

expect(() => functionCall(...params)).toThrowProjectError();

expect(() => functionCall(...params)).toThrowProjectError(InternalError, "Internal Application", /internal application/i);

🚀 Deployment

npm run publish

📝 Changelog

1.0.2: Split toThrowProjectError() into sync and totoThrowProjectErrorAsync() versions
1.0.1: toThrowProjectError() supports async functions
1.0.0: arbitrary starting point
0.4.0: adds toThrowProjectError() (unpublished)
0.3.0: adds toBeAsyncIterator()
0.2.0: adds toBeCalledWithInitialParams()
0.1.0: adds toBeClass()

nullfame/knowdev-jest