Effector vs MobX: What are the differences?

Introduction:

Effector and MobX are both state management libraries for JavaScript applications. While they serve a similar purpose, there are key differences between the two.

1. 1. Integration with React:

Effector is designed to work seamlessly with React, providing a set of React-specific APIs to manage state. It offers hooks and components that allow for an intuitive integration with React components. On the other hand, MobX can be used with React, but it is not tightly coupled with it. It follows a more standalone approach, allowing it to be used with other frameworks or even vanilla JavaScript.

2. 2. Dependency Tracking:

Effector adopts an explicit dependency tracking mechanism, where you define dependencies between different state units explicitly. It utilizes a directed acyclic graph (DAG) to efficiently compute and update dependencies when specific state units change. MobX, on the other hand, relies on an implicit dependency tracking mechanism. It uses a transparent reactivity system that automatically infers dependencies based on the observed access and mutations of state. This can lead to a more implicit and intuitive programming model.

3. 3. Performance Optimization:

Effector focuses on performance optimization by default. It utilizes fine-grained updates, allowing only the necessary components to re-render when specific state changes occur. It also provides built-in support for batching updates, reducing the number of re-renders and improving overall performance. MobX, while highly performant, provides less granular control over updates by default. However, it offers additional mechanisms, such as the observer higher-order component, to optimize rendering and prevent unnecessary updates.

4. 4. Immutability vs Mutability:

Effector promotes immutability as a core principle. It encourages immutability by default and discourages direct mutations of state. It provides utilities to work with immutable data structures and updates state indirectly through actions and events. MobX, on the other hand, is more permissive with regard to mutability. It allows direct mutations of state while still ensuring reactivity through its observable and computed mechanisms.

5. 5. Developer Experience:

Effector puts a strong emphasis on type safety and developer experience. It provides a statically-typed API and full TypeScript support out of the box. Its API is designed to be ergonomic and intuitive, allowing for concise and expressive code. MobX, while also having TypeScript support, provides a more dynamic and flexible API that may require extra care for type safety and error handling.

6. 6. Community and Ecosystem:

Effector, being a relatively new library, has a smaller and growing community compared to MobX. The ecosystem around Effector is evolving, which means that it may have fewer third-party libraries and integrations available. MobX, on the other hand, has a larger and more established community, offering a wide range of third-party libraries, tools, and frameworks that can enhance the development experience.

In summary, Effector provides tight integration with React, explicit dependency tracking, performance optimization, immutability by default, strong developer experience, and a growing ecosystem. MobX, while also having React integration, offers implicit dependency tracking, additional performance optimization mechanisms, flexibility with mutability, a dynamic API, and a mature ecosystem.