The core concept of Marble.js assumes that almost everything is a stream. The main building block of the whole framework is an Effect, which is just a function that returns a stream of events. With the big popularity of RxJS Observable, you can create a referential transparent program specification made up of functions that may produce side effects like network, logging, database access, etc. Using its monadic nature we can map I/O operations over effects and flat them to bring in other sequences of operations. RxJS is used as a hammer for expressing asynchronous flow with monadic manner.
Marble.js doesn't operate only over basic HTTP protocol but can be used also for general MDA (Message-Driven Architecture) solutions, including WebSocket, microservices or CQRS, where the multi-event nature fits best. Don't be scared of the complexity and abstractions — Marble.js framework, in general, is incredibly simple. For more details about its specifics, please visit the next chapters that will guide you through the framework environment and implementation details.
For those who are curious about the framework name - it comes from a popular way of visually expressing the time-based behavior of event streams, aka marble diagrams. This kind of domain-specific language is a popular way of testing asynchronous streams, especially in RxJS environments.
If you would like to get a quick glimpse of a simple RESTful API built with Marble.js, visit the following link: