@nan0web/transformer

Basic and agnostic transformer.

|Package name|Status|Documentation|Test coverage|Features|Npm version| |---|---|---|---|---|---| |@nan0web/transformer |🟢 99.7% |🧪 English 🏴󠁧󠁢󠁥󠁮󠁧󠁿Українською 🇺🇦 |🟢 100.0% |✅ d.ts 📜 system.md 🕹️ playground |— |

Description

The @nan0web/transformer package provides a lightweight and flexible foundation for sequential data transformation. It allows you to chain multiple transformation steps (transformers) that can encode and decode data in a predictable, composable way.

A Transformer instance collects transformer objects and applies their encode or decode methods in sequence. Each transformer may implement one or both methods, and the process is fully asynchronous, allowing integration with async operations.

This package is ideal for:

• Building data pipelines (e.g., encryption, compression, formatting)
• Creating serialization/deserialization layers
• Developing middleware-like processing sequences
• Any scenario where data must pass through multiple stages of transformation

Installation

How to install with npm?

npm install @nan0web/transformer

How to install with pnpm?

pnpm add @nan0web/transformer

How to install with yarn?

yarn add @nan0web/transformer

Usage

Basic Transformation

Create a Transformer and add transformer objects with encode and/or decode methods.

How to chain multiple encoders?

import { Transformer } from '@nan0web/transformer'
const transformer = new Transformer()

const upperCase = {
	encode: async (data) => data.toUpperCase(),
	decode: async (data) => data.toLowerCase()
}

const addPrefix = {
	encode: async (data) => `[ENC] ${data}`,
	decode: async (data) => data.replace(/^\[ENC\]\s/i, '')
}

transformer.addTransformer(upperCase)
transformer.addTransformer(addPrefix)

const encoded = await transformer.encode("hello world")
console.info(encoded) // [ENC] HELLO WORLD

const decoded = await transformer.decode(encoded)
console.info(decoded) // hello world

How to add and remove transformers dynamically?

import { Transformer } from '@nan0web/transformer'
const transformer = new Transformer()

const spyTransformer = {
	encode: async (data) => `${data} • spy`,
	decode: async (data) => data.replace(/ • spy$/, '')
}

transformer.addTransformer(spyTransformer)
console.info(transformer.transformers) // ← [spyTransformer]

transformer.removeTransformer(spyTransformer)
console.info(transformer.transformers) // ← []

Skip Non-Implementing Transformers

Transformers without encode or decode methods are skipped automatically.

How to ensure only transformers with encode/decode are applied?

import { Transformer } from '@nan0web/transformer'
const transformer = new Transformer()

const validEncoder = {
	encode: async (data) => data + "•encoded"
}

const invalidTransformer = {
	process: async (data) => data
}

transformer.addTransformer(validEncoder)
transformer.addTransformer(invalidTransformer)

const result = await transformer.encode("data")
console.info(result) // data•encoded

Asynchronous Transformers

All transformations are async, enabling integration with promises and async operations.

How to use asynchronous transformations with delays?

import { Transformer } from '@nan0web/transformer'
const transformer = new Transformer()

const delayEncode = {
	encode: async (data) => {
		await new Promise(r => setTimeout(r, 10))
		return `[DELAYED] ${data}`
	}
}

transformer.addTransformer(delayEncode)
const result = await transformer.encode("test")
console.info(result) // [DELAYED] test

API

Transformer

A class that manages a sequence of transformers.

• Constructor

  • new Transformer() — creates an empty transformer chain.

• Properties

  • transformers – array of transformer objects added via addTransformer.

• Methods

  • encode(data) – applies all encode methods in sequence.
  • decode(data) – applies all decode methods in sequence.
  • addTransformer(t) – adds a transformer object to the chain.
  • removeTransformer(t) – removes a specific transformer object from the chain.

All methods return promises and are await-safe.

Java•Script

Uses d.ts files for autocompletion

CLI Playground

Run local experiments using the playground script.

How to run playground script?

# Run the playground
npm run play

Contributing

This project follows strict testing and linting rules.

How to contribute? - check here

License

Licensed under ISC.

How to license ISC? - check here