Node Stream API

Stream manipulation utilities for size limiting, buffering, and merging.

What It Does

The Node Stream API provides specialized utilities for Node.js stream processing, including size-limited uploads, stream buffering to strings, and stream merging for data pipelines.

Key Capabilities

• Size Limiting: Enforce upload size limits with automatic stream destruction
• Stream Buffering: Convert readable streams to complete strings
• Stream Merging: Combine multiple streams sequentially
• Flexible Size Parsing: Support human-readable sizes (100mb, 2gb)
• Error Integration: E11Error format for size limit violations

Main Utilities

limitSize

limitSize(sizeLimit: string): Transform

Creates Transform stream that enforces file size limits:

• Monitors cumulative chunk sizes
• Destroys stream with SizeLimitError if exceeded
• Supports formats: “10mb”, “2gb”, etc.

bufferStream

async bufferStream(stream: Readable): Promise<string>

Accumulates stream into complete UTF-8 string:

• Handles streaming errors
• Returns complete data as Promise
• Memory-efficient for moderate-sized data

mergeStreams

mergeStreams(streams: Readable[]): Readable

Combines multiple streams sequentially:

• Uses async generators
• Sequential data yielding
• Single merged output stream

SizeLimitError

Custom error class with E11Error integration:

• Type: SIZE_LIMIT_REACHED
• Includes size limit in error data

Usage Example

// Limit upload size
const limitedStream = uploadStream.pipe(limitSize('100mb'))
 
// Buffer stream to string
const content = await bufferStream(fileStream)
 
// Merge multiple data sources
const combined = mergeStreams([stream1, stream2, stream3])

Common Use Cases

• File upload size validation
• Stream consumption to strings
• Multi-source data combination
• Memory-safe stream processing
• Upload protection

What Customers Don’t Have to Build

• Size limit enforcement
• Stream buffering logic
• Stream merging utilities
• Size parsing (mb, gb, etc.)
• Error handling for streams
• Transform stream creation