Flowlet

Note

🌀 A minimal and fluent flow control utility for TypeScript — sync and async steps made clean.

Flowlet helps you build elegant, composable flows where each step can be synchronous or asynchronous. With a small API and expressive syntax, it simplifies chaining operations, transforming data, and handling side effects clearly and predictably.

🚀 Features

• ✨ Fluent API for chaining logic
• 🔁 Supports both sync and async flows
• 🔍 tap for debugging or side effects
• 🔄 step, asyncStep, map, and then for maximum clarity
• 🪶 Lightweight and TypeScript-native

📦 Installation

npm install flowlet

🧩 Basic Usage

import { Flow } from "flowlet";

const getUser = ({ user }: { user: string }) => ({ password: "123" });
const encryptPassword = ({ password }: { password: string }) => ({
  token: "abc",
});
const writeLog = async ({ token }: { token: string }) => {
  console.log("Writing log...");
  await new Promise((res) => setTimeout(res, 1000));
  return { token };
};

const result = await Flow.start({ user: "admin" })
  .step(getUser)
  .step(encryptPassword)
  .tap(({ token }) => console.log("Token:", token))
  .asyncStep(writeLog)
  .then((pipe) => pipe.step(({ token }) => ({ body: token })));

console.log("Response:", result.end());

📘 API Reference

Method	Description	Returns
Flow.start(data)	Starts a new flow with the given context.	Flow<T>
.step(fn)	Applies a synchronous transformation to the flow context.	Flow<U>
.asyncStep(fn)	Applies an asynchronous transformation to the flow context.	AsyncFlow<U>
.then(fn)	Resumes the flow after an async step. Receives a new Flow.	Promise<Flow<U>>
.tap(fn)	Runs a side-effect or debug function without altering the context.	Flow<T>
.end()	Returns the final resolved context from the flow.	T

Note

Type variables: T is the current context type, U is the result type after transformation.

📘 Why Flowlet?

Traditional chaining often mixes sync and async logic in a way that’s hard to follow. Flowlet brings structure, readability, and elegance to your data processing logic — like a mini pipeline engine, without the overhead.

🛠️ License

MIT © CodeHiveColombia