uniqs

library2.0.0jsnpmunverified

uniqs is a lightweight JavaScript utility designed to create unique lists and unions of multiple lists, defining uniqueness based on strict object equality. Currently at version 2.0.0, this package distinguishes itself by prioritizing simplicity and a minimal footprint over raw performance, making it a suitable alternative to more comprehensive libraries like Lodash or Underscore for basic deduplication tasks. Its primary purpose is to provide a straightforward function for de-duplicating items and combining arrays without complex features or external dependencies, making it ideal for scenarios where bundle size and directness are critical. Items are maintained in their first-appearance order, reflecting their initial encounter in the input lists.

serialization data

npm install uniqs

github ↗package ↗

INSTALL

IMPORT

SIG · UNIQS

uniqs

serializationjavascriptv2.0.0

Install

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Import

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Disk

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Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

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

uniqs

✓ const uniqs = require('uniqs');

✗ import { uniqs } from 'uniqs';

The package primarily uses CommonJS `require` for its default function export. While ESM `import uniqs from 'uniqs'` may work in some environments, it's not explicitly stated or guaranteed by the README.

uniqs

✓ import uniqs from 'uniqs';

✗ const { uniqs } = require('uniqs');

For ESM environments, assuming a default export, this is the standard import. Attempting to destructure it as a named export from CommonJS will fail.

Demonstrates deduplication of a single list, union of multiple lists, and handling of mixed individual items and lists.

const uniqs = require('uniqs'); // Example usage to deduplicate a list const foo = { id: 23 }; const list = [3, 2, 2, 1, foo, foo]; const uniqueList = uniqs(list); console.log('Unique list:', uniqueList); // Expected: [3, 2, 1, { id: 23 }] // Example usage to create a union of multiple lists const listA = [2, 1, 1]; const listB = [2, 3, 3, 4]; const listC = [4, 3, 2]; const unionList = uniqs(listA, listB, listC); console.log('Union list:', unionList); // Expected: [2, 1, 3, 4] // Example with individual items and a list const mixedInput = uniqs(3, 2, 2, [1, 1, 2]); console.log('Mixed input:', mixedInput); // Expected: [3, 2, 1]

Debug

Known issues

gotchauniqs uses a simple `indexOf`-based deduplication, resulting in O(n^2) time complexity for the combined list. This can lead to significant performance degradation on large arrays (thousands of items or more).

fix

For performance-critical applications or very large datasets, consider alternatives like JavaScript's native `Set` or `Lodash.uniq` which offer better time complexity (O(n)).

affects: >=1.0.0

gotchaUniqueness is determined solely by strict (`===`) object equality. This means two objects with identical properties but different references (e.g., `{a: 1}` and another `{a: 1}`) will be considered distinct items.

fix

To deduplicate objects based on deep equality, you must implement custom serialization (e.g., `JSON.stringify`) or a custom comparison logic before passing them to `uniqs`, or use a library that supports deep comparisons.

affects: >=1.0.0

breakingThe transition to version 2.0.0 implies potential breaking changes as per semantic versioning. While specific details are not provided in the excerpt, developers upgrading from 1.x should expect behavioral shifts.

fix

Review the package's changelog or release notes for version 2.0.0 to understand specific breaking changes and update your codebase accordingly.

affects: >=2.0.0

Errors

Common errors & fixes

Expected [ { a: 1 }, { a: 1 } ] to be unique, but got two distinct objects.

`uniqs` uses strict (===) equality, so two different object instances, even with identical content, are considered unique.

fix

If you need deep equality, serialize objects (e.g., `JSON.stringify`) or use a custom comparison function before passing them to `uniqs`, or switch to a library that supports deep equality.

Application hangs or runs very slowly when processing a large array with `uniqs`.

The internal implementation of `uniqs` has O(n^2) complexity, making it inefficient for very large input arrays due to repeated `indexOf` calls.

fix

For performance-critical applications with large datasets, use JavaScript's built-in `Set` for O(n) performance with primitive values, or a more optimized library function like Lodash's `uniq` for objects.

Upgrade

Version history

2.0.0latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

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Resources

githubhttps://github.com/fgnass/uniqs ↗

packagehttps://www.npmjs.com/package/uniqs ↗