AVA vs Mocha: What are the differences?

## Key Differences between AVA and Mocha

AVA and Mocha are both popular JavaScript testing frameworks, but they have some key differences that set them apart. 

1. **Concurrency**: AVA runs tests concurrently, allowing for faster test execution compared to Mocha, which runs tests sequentially. This can be beneficial for large test suites as it helps in reducing overall testing time.
2. **Syntax**: Mocha uses a simple and flexible syntax, making it easier for beginners to get started with testing. On the other hand, AVA uses a more opinionated syntax that enforces certain testing practices, providing a more structured approach to writing tests.
3. **Isolation**: AVA sandboxes each test file, running them in parallel to prevent any interference between tests. In contrast, Mocha runs all tests within the same process, potentially causing issues with test data leaking between tests.
4. **Installation**: Mocha requires additional setup and installation of assertion libraries like Chai, while AVA comes bundled with its own assertion library. This makes AVA a more lightweight and self-sufficient solution for testing.
5. **Asynchronous Testing**: AVA natively supports promises and async/await syntax for handling asynchronous operations, making it easier to write and maintain asynchronous tests. Mocha, on the other hand, may require additional setup or plugins to enable this functionality.
6. **Configuration**: Mocha provides more flexibility in configuration options, allowing users to customize test runners, reporters, and other settings. AVA, on the other hand, comes with a minimalistic configuration approach, which may be preferred by those looking for simplicity.

In Summary, AVA and Mocha differ in terms of concurrency, syntax, isolation, installation, asynchronous testing support, and configuration options.