stream-shift

library1.0.3jsnpmunverified

Returns the next buffer/object in a Node.js stream's readable queue without consuming it. Version 1.0.3 is the latest stable release. The package is minimal and focused, primarily used internally by higher-level stream utilities. It works on Node.js 6+ and is commonly used in modules like `pump`, `through2`, and others that need to peek into a stream's internal buffer. It is not a user-facing tool but a low-level utility for stream manipulation.

storage

npm install stream-shift

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · STREAM-SHIFT

stream-shift

storagejavascriptv1.0.3

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

shift

✓ import shift from 'stream-shift'

✗ const { shift } = require('stream-shift')

The package exports a single default function. Use default import in ESM or require in CJS.

default import (CommonJS)

✓ const shift = require('stream-shift')

✗ const { shift } = require('stream-shift')

CommonJS requires the entire module as the function.

TypeScript type

✓ import shift from 'stream-shift'

✗ import * as shift from 'stream-shift'

TypeScript type definitions are not bundled; use @types/stream-shift if needed.

Demonstrates using stream-shift to read the next buffers from a readable stream's queue without consuming them.

import shift from 'stream-shift'; import { Readable } from 'stream'; const stream = new Readable({ read() { this.push('buffer1'); this.push('buffer2'); this.push(null); } }); // Wait for data to be buffered stream.on('readable', () => { const first = shift(stream); console.log(first); // 'buffer1' const second = shift(stream); console.log(second); // 'buffer2' });

Debug

Known issues

gotchashift() returns null if the stream has ended or is in flowing mode.

fix

Always check for null before using the returned value.

affects: all

gotchashift() does not remove the item from the queue; it only reads it. The item will still be emitted on next 'data' event.

fix

Use shift() only for peeking; consume the stream normally with read() or 'data' event to advance the queue.

affects: all

gotchaCalling shift() on a stream in object mode returns the next object, not a Buffer.

fix

Ensure your stream is in object mode if you expect objects, or in binary mode for Buffers.

affects: all

Errors

Common errors & fixes

TypeError: stream.shift is not a function

Using incorrect import or calling shift as a method on the stream object.

fix

Use shift(stream) instead of stream.shift() and import shift from 'stream-shift'.

import shift from 'stream-shift'; SyntaxError: Unexpected identifier

Using ESM syntax in a CommonJS environment without a bundler or 'type': 'module' in package.json.

fix

Use const shift = require('stream-shift'); instead.

Upgrade

Version history

1.0.3latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

37 hits · last 30 days

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Resources

githubhttps://github.com/mafintosh/stream-shift ↗

packagestream-shift ↗

homepagehttps://github.com/mafintosh/stream-shift ↗