- Refactor tests to use Node's native fs streams instead of @push.rocks/smartfile.fsStream and export default tap.start() to support ESM test runner patterns.
- Adjust build/publish: remove --web flag from build script, add pnpm override for agentkeepalive, add tspublish.json files for publish order, and add release registries/access in npmextra.json (verdaccio + npm).
- Rework project metadata in npmextra.json (namespaced @git.zone keys, tsdoc entry changes) and minor TypeScript/web fix: cast stream/web constructors to any in ts_web/plugins.ts.
- Large README rewrite: improved installation (pnpm), clearer Node vs Web entrypoints, expanded examples, and updated legal/license wording.
## 2024-11-19 - 3.2.5 - fix(nodewebhelpers)
Fix import and use correct module structure for Node.js streams in smartstream.nodewebhelpers.ts
"legal":"\n## License and Legal Information\n\nThis repository contains open-source code that is licensed under the MIT License. A copy of the MIT License can be found in the [license](license) file within this repository. \n\n**Please note:** The MIT License does not grant permission to use the trade names, trademarks, service marks, or product names of the project, except as required for reasonable and customary use in describing the origin of the work and reproducing the content of the NOTICE file.\n\n### Trademarks\n\nThis project is owned and maintained by Task Venture Capital GmbH. The names and logos associated with Task Venture Capital GmbH and any related products or services are trademarks of Task Venture Capital GmbH and are not included within the scope of the MIT license granted herein. Use of these trademarks must comply with Task Venture Capital GmbH's Trademark Guidelines, and any usage must be approved in writing by Task Venture Capital GmbH.\n\n### Company Information\n\nTask Venture Capital GmbH \nRegistered at District court Bremen HRB 35230 HB, Germany\n\nFor any legal inquiries or if you require further information, please contact us via email at hello@task.vc.\n\nBy using this repository, you acknowledge that you have read this section, agree to comply with its terms, and understand that the licensing of the code does not imply endorsement by Task Venture Capital GmbH of any derivative works.\n"
A TypeScript library to simplify the creation and manipulation of Node.js streams, providing utilities for transform, duplex, and readable/writable stream handling while managing backpressure effectively.
A TypeScript-first library for creating and manipulating Node.js and Web streams with built-in backpressure handling, async transformations, and seamless Node.js ↔ Web stream interoperability.
## Issue Reporting and Security
For reporting bugs, issues, or security vulnerabilities, please visit [community.foss.global/](https://community.foss.global/). This is the central community hub for all issue reporting. Developers who sign and comply with our contribution agreement and go through identification can also get a [code.foss.global/](https://code.foss.global/) account to submit Pull Requests directly.
## Install
To install `@push.rocks/smartstream`, you can use npm or yarn as follows:
```bash
npm install @push.rocks/smartstream --save
# OR
yarn add @push.rocks/smartstream
pnpm install @push.rocks/smartstream
```
This will add `@push.rocks/smartstream` to your project's dependencies.
The package ships with two entry points:
| Entry Point | Import Path | Environment |
|---|---|---|
| **Node.js** (default) | `@push.rocks/smartstream` | Node.js — full stream utilities, duplex, intake, wrappers, and Node↔Web helpers |
| **Web** | `@push.rocks/smartstream/web` | Browser & Node.js — pure Web Streams API (`WebDuplexStream`) |
## Usage
The `@push.rocks/smartstream` module is designed to simplify working with Node.js streams by providing a set of utilities for creating and manipulating streams. This module makes extensive use of TypeScript for improved code quality, readability, and maintenance. ESM syntax is utilized throughout the examples.
All examples use ESM / TypeScript syntax.
### Importing the Module
Start by importing the module into your TypeScript file:
For a more specific import, you may do the following:
---
### 🔄 SmartDuplex — The Core Stream Primitive
`SmartDuplex` extends Node.js `Duplex` with first-class async support, built-in backpressure management, and a clean functional API. Instead of overriding `_transform` or `_write` manually, you pass a `writeFunction` that receives each chunk along with a `tools` object.
The module provides utilities for creating transform streams. For example, to create a transform stream that modifies chunks of data, you can use the `createTransformFunction` utility:
The `writeFunction` can emit multiple chunks per input via `tools.push()`:
```typescript
constsplitter=newSmartDuplex<string,string>({
objectMode: true,
writeFunction: async(chunk,tools)=>{
constwords=chunk.split(' ');
for(constwordofwords){
awaittools.push(word);
}
// Returning nothing — output was already pushed
},
});
```
#### Final Function
Run cleanup or emit final data when the writable side ends:
```typescript
constaggregator=newSmartDuplex<number,number>({
objectMode: true,
writeFunction: async(chunk,tools)=>{
runningTotal+=chunk;
// Don't emit anything per-chunk
},
finalFunction: async(tools)=>{
returnrunningTotal;// Emitted as the last chunk
},
});
```
#### Truncating a Stream Early
Call `tools.truncate()` inside `writeFunction` to signal that no more data should be read:
Pass `debug: true` and `name` to get detailed internal logs:
```typescript
conststream=newSmartDuplex({
name:'MyStream',
debug: true,
writeFunction: async(chunk,tools)=>chunk,
});
```
---
### 🧩 StreamWrapper — Pipeline Composition
`StreamWrapper` takes an array of streams, pipes them together, attaches error listeners on all of them, and returns a `Promise` that resolves when the pipeline finishes:
You can also listen for custom events across all streams:
```typescript
pipeline.onCustomEvent('progress',()=>{
console.log('Progress event fired');
});
```
---
### 📥 StreamIntake — Dynamic Data Injection
`StreamIntake` is a `Readable` stream that lets you programmatically push data into a pipeline. It operates in object mode by default and provides a reactive observable (`pushNextObservable`) for demand-driven data production.
`SmartDuplex` is a powerful part of the `smartstream` module designed to handle backpressure effectively. Here's an example of how to create a `SmartDuplex` stream that processes data and respects the consumer's pace:
`Smartstream` facilitates easy combining of multiple streams into a single pipeline, handling errors and cleanup automatically. Here's how you can combine multiple streams:
### 🔀 Node ↔ Web Stream Converters
The `nodewebhelpers` namespace provides bidirectional converters between Node.js and Web Streams:
Consider a scenario where you need to process a large CSV file, transform the data row-by-row, and then write the results to a database or another file. With `smartstream`, you could create a pipe that reads the CSV, processes each row, and handles backpressure, ensuring efficient use of resources.
This example demonstrates reading a large CSV file, transforming each row with `createTransformFunction`, and using a `SmartDuplex` to manage the processed data flow efficiently, ensuring no data is lost due to backpressure issues.
---
### Advanced Use Case: Backpressure Handling
### 🏗️ Backpressure Handling
Effective backpressure handling is crucial when working with streams to avoid overwhelming the downstream consumers. Here’s a comprehensive example that demonstrates handling backpressure in a pipeline with multiple `SmartDuplex` instances:
`SmartDuplex` uses a `BackpressuredArray` internally, bounded by `highWaterMark` (default: 1). When the downstream consumer is slow, the stream automatically pauses the upstream producer until space is available — no manual bookkeeping required.
```typescript
import{SmartDuplex}from'@push.rocks/smartstream';
// Define the first SmartDuplex, which writes data slowly to simulate backpressure
.on('error',error=>console.error('Stream encountered an error:',error));
// Simulate data pushing with intervals to observe backpressure handling
letcounter=0;
constinterval=setInterval(()=>{
if(counter>=10){
streamIntake.signalEnd();
clearInterval(interval);
}else{
streamIntake.pushData(`Chunk ${counter}`);
counter++;
}
},50);
for(leti=0;i<100;i++){
fast.write(`chunk-${i}`);
}
fast.end();
```
In this advanced use case, a `SlowProcessor` and `FastProcessor` are created using `SmartDuplex`, simulating a situation where one stream is slower than another. The `StreamIntake` dynamically handles incoming chunks of data and the intermediary Pass-Through handles any potential interruptions.
---
### Transform Streams in Parallel
For scenarios where you need to process data in parallel:
Error handling is an essential part of working with streams. The `StreamWrapper` assists in combining multiple streams while managing errors seamlessly:
You can easily stream files and buffers with `smartstream`. Here’s a test illustrating reading and writing with file streams using `smartfile` combined with `smartstream` utilities:
By leveraging `SmartDuplex`, `StreamWrapper`, and `StreamIntake`, you can streamline and enhance your data transformation pipelines in Node.js with a clear, efficient, and backpressure-friendly approach.
```
## License and Legal Information
This repository contains open-source code that is licensed under the MIT License. A copy of the MIT License can be found in the [license](license) file within this repository.
This repository contains open-source code licensed under the MIT License. A copy of the license can be found in the [LICENSE](./LICENSE) file.
**Please note:** The MIT License does not grant permission to use the trade names, trademarks, service marks, or product names of the project, except as required for reasonable and customary use in describing the origin of the work and reproducing the content of the NOTICE file.
### Trademarks
This project is owned and maintained by Task Venture Capital GmbH. The names and logos associated with Task Venture Capital GmbH and any related products or services are trademarks of Task Venture Capital GmbH and are not included within the scope of the MIT license granted herein. Use of these trademarks must comply with Task Venture Capital GmbH's Trademark Guidelines, and any usage must be approved in writing by Task Venture Capital GmbH.
This project is owned and maintained by Task Venture Capital GmbH. The names and logos associated with Task Venture Capital GmbH and any related products or services are trademarks of Task Venture Capital GmbH or third parties, and are not included within the scope of the MIT license granted herein.
Use of these trademarks must comply with Task Venture Capital GmbH's Trademark Guidelines or the guidelines of the respective third-party owners, and any usage must be approved in writing. Third-party trademarks used herein are the property of their respective owners and used only in a descriptive manner, e.g. for an implementation of an API or similar.
### Company Information
Task Venture Capital GmbH
Registered at District court Bremen HRB 35230 HB, Germany
Task Venture Capital GmbH
Registered at District Court Bremen HRB 35230 HB, Germany
For any legal inquiries or if you require further information, please contact us via email at hello@task.vc.
For any legal inquiries or further information, please contact us via email at hello@task.vc.
By using this repository, you acknowledge that you have read this section, agree to comply with its terms, and understand that the licensing of the code does not imply endorsement by Task Venture Capital GmbH of any derivative works.
description:'A library to simplify the creation and manipulation of Node.js streams, providing utilities for handling transform, duplex, and readable/writable streams effectively in TypeScript.'
description:'A library to simplify the creation and manipulation of Node.js streams, providing utilities for handling transform, duplex, and readable/writable streams effectively in TypeScript.'
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