Guide

xJet is a modern, extensible test and mocking toolkit designed for JavaScript and TypeScript ecosystems. It combines test definitions, matchers, mocks, spies, logging utilities, and more, aiming to offer a streamlined, expressive, and highly productive developer experience for creating robust automated tests.

Key Features

• Flexible Test Definitions:
  Define tests using familiar patterns (test, it, describe, etc.), with support for lifecycle hooks (beforeEach, afterEach, etc.) and data-driven testing.

• Advanced Mocking:
  Easily mock functions, constructors, and methods, including global and object-bound members, with features like mockImplementation,

• call history tracking, return value injection, and restoration of original implementations.

• Powerful Spies:
  Observe and assert upon function calls without altering their implementation.

• Comprehensive Matchers:
  Rich set of matchers for all common data types, including objects, numbers, strings, and functions, designed for precise assertions and clear error messages.

• Integrated Logging:
  Unified logging methods (log, info, warn, error, debug) routed to the test runner, enhancing test traceability and debugging.

• Automated Mock Management:
  Easily clear, reset, or restore all mocks globally, ensuring stateful tests remain isolated and repeatable.

• TypeScript-Friendly:
  All APIs are fully typed for maximum safety, autocomplete, and great IDE support.

• Runner Integration:
  Outputs and logs are friendly for CI pipelines, terminals, and IDEs — helping you see what’s happening in tests at a glance.

Typical Usage Example

describe('User model', () => {
    beforeEach(() => {
        xJet.resetAllMocks();
    });
    
    test('creates a user with default status', () => {
        const user = new User('Alice');
        expect(user.status).toBe('active');
    });
    
    test('logs errors on invalid input', () => {
        const logSpy = xJet.spyOn(console, 'error');
        new User(null);
        expect(logSpy).toHaveBeenCalled();
    });
    
    test('can be mocked', () => {
        const constructorMock = xJet.mock(User);
        constructorMock.mockImplementation((name) => ({ name: `Mocked ${ name }` }));
        const user = new User('Bob');
        expect(user.name).toBe('Mocked Bob');
        constructorMock.mockRestore();
    });
});

Core Modules

• Test Definition & Lifecycle:
  describe, test, it, beforeAll, afterAll, beforeEach, afterEach

• Mocking & Spying:
  xJet.mock, xJet.fn, xJet.spyOn

• Matchers:
  expect(...).toBe(...), .toEqual(...), .toHaveBeenCalled(), and more

• Logging:
  xJet.log, xJet.info, xJet.warn, xJet.error, xJet.debug

• Global Utilities:
  Utilities for managing test and mock state, configuration, and reporting

Getting Started

• Add @remotex-labs/xjet as a dependency to your project
• Initialize your test files with xJet globals available
• Use the provided APIs for defining, structuring, and verifying your tests with optimal productivity and clarity

Run: