Question 1

How to get started with Cycle.js and RxJS?

Accepted Answer

Install @cycle/rxjs-run and @cycle/dom packages, then define your main function as a pure function that takes sources like DOM events and returns sinks. The official documentation provides examples on setting up the runtime with RxJS for reactive streams.

Question 2

Cycle.js vs React: which is better for functional programming?

Accepted Answer

Cycle.js is built from the ground up on functional reactive principles, enforcing pure functions and side effect separation, while React uses a more imperative approach with hooks. Cycle.js offers more predictability, but React has a larger ecosystem and easier onboarding.

Question 3

What are best practices for testing Cycle.js applications?

Accepted Answer

Since apps are pure functions, test by mocking observable sources (e.g., simulated DOM events) and asserting on sinks. Use testing utilities from stream libraries like xstream or RxJS to control streams and verify outputs, leveraging the framework's predictable nature.

Question 4

How does Cycle.js handle state management compared to Redux?

Accepted Answer

Cycle.js models state as observable streams within pure functions, eliminating the need for a separate library like Redux. State flows reactively through functions, reducing boilerplate and enforcing unidirectional data flow without explicit dispatchers.

Question 5

Is Cycle.js production-ready for large-scale applications?

Accepted Answer

Yes, with caveats: its modularity and isolation features support large codebases, but the smaller ecosystem may require more custom tooling. Success depends on the team's comfort with FRP and willingness to invest in learning and maintenance.

Question 6

How to perform HTTP requests in Cycle.js?

Accepted Answer

Use the @cycle/http package to define HTTP sources and sinks in your main function. Emit requests as streams and handle responses reactively, integrating with other streams for data flow, as detailed in the package documentation.

Question 7

What stream library should I use with Cycle.js: xstream, RxJS, or Most.js?

Accepted Answer

Xstream is lightweight and designed for Cycle.js, RxJS has a larger community and more operators, and Most.js focuses on performance. Choose based on project size, feature needs, and team familiarity, as all are supported through dedicated run packages.

@cycle/http

What is @cycle/http?

Overview

Use Cases

Best For

Found a gem we're missing?

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions