fast-is-equal

Blazing-fast equality checks, minus the baggage. A lean, standalone alternative to Lodash’s isEqual—because speed matters.

Installation

Using yarn:

yarn add fast-is-equal

Using npm:

npm install fast-is-equal

Usage

import { fastIsEqual } from 'fast-is-equal';

console.log(fastIsEqual(1, 1)); // true
console.log(fastIsEqual({ a: 1 }, { a: 1 })); // true
console.log(fastIsEqual([1, 2], [1, 3])); // false

Features

• Lightweight and dependency-free.
• Handles primitives, objects, arrays, Maps, Sets, circular references, and more.
• Optimized for performance (see benchmarks).

Benchmarks

fast-is-equal outperforms Lodash’s isEqual in most cases. Run npm run benchmark locally to compare: ```bash Performance Comparison: fastIsEqual vs Lodash isEqual Iterations per test case: 1000000

Test Case 1: Numbers fastIsEqual: 0.000003 ms Lodash isEqual: 0.000006 ms Difference (fastIsEqual - Lodash): -0.000002 ms fastIsEqual is 1.62x faster than Lodash

Test Case 2: Strings fastIsEqual: 0.000005 ms Lodash isEqual: 0.000005 ms Difference (fastIsEqual - Lodash): -0.000000 ms fastIsEqual is 1.08x faster than Lodash

Test Case 3: Booleans fastIsEqual: 0.000005 ms Lodash isEqual: 0.000005 ms Difference (fastIsEqual - Lodash): -0.000000 ms fastIsEqual is 1.06x faster than Lodash

Test Case 4: NaN fastIsEqual: 0.000006 ms Lodash isEqual: 0.000012 ms Difference (fastIsEqual - Lodash): -0.000006 ms fastIsEqual is 1.98x faster than Lodash

Test Case 5: Simple Object (equal) fastIsEqual: 0.000097 ms Lodash isEqual: 0.000271 ms Difference (fastIsEqual - Lodash): -0.000174 ms fastIsEqual is 2.80x faster than Lodash

Test Case 6: Simple Object (unequal) fastIsEqual: 0.000105 ms Lodash isEqual: 0.000271 ms Difference (fastIsEqual - Lodash): -0.000165 ms fastIsEqual is 2.57x faster than Lodash

Test Case 7: Nested Object (equal) fastIsEqual: 0.000184 ms Lodash isEqual: 0.000835 ms Difference (fastIsEqual - Lodash): -0.000651 ms fastIsEqual is 4.53x faster than Lodash

Test Case 8: Nested Object (unequal) fastIsEqual: 0.000197 ms Lodash isEqual: 0.000850 ms Difference (fastIsEqual - Lodash): -0.000653 ms fastIsEqual is 4.31x faster than Lodash

Test Case 9: Array of Primitives (equal) fastIsEqual: 0.000017 ms Lodash isEqual: 0.000102 ms Difference (fastIsEqual - Lodash): -0.000085 ms fastIsEqual is 5.95x faster than Lodash

Test Case 10: Array of Primitives (unequal) fastIsEqual: 0.000015 ms Lodash isEqual: 0.000103 ms Difference (fastIsEqual - Lodash): -0.000088 ms fastIsEqual is 6.79x faster than Lodash

Test Case 11: Array of Objects (equal) fastIsEqual: 0.000078 ms Lodash isEqual: 0.000638 ms Difference (fastIsEqual - Lodash): -0.000560 ms fastIsEqual is 8.15x faster than Lodash

Test Case 12: Circular Reference fastIsEqual: 0.000095 ms Lodash isEqual: 0.000493 ms Difference (fastIsEqual - Lodash): -0.000399 ms fastIsEqual is 5.22x faster than Lodash

Test Case 13: Map (equal) fastIsEqual: 0.000074 ms Lodash isEqual: 0.001383 ms Difference (fastIsEqual - Lodash): -0.001309 ms fastIsEqual is 18.67x faster than Lodash

Test Case 14: Map (unequal) fastIsEqual: 0.000076 ms Lodash isEqual: 0.001330 ms Difference (fastIsEqual - Lodash): -0.001255 ms fastIsEqual is 17.59x faster than Lodash

Test Case 15: Set (equal) fastIsEqual: 0.000073 ms Lodash isEqual: 0.000949 ms Difference (fastIsEqual - Lodash): -0.000876 ms fastIsEqual is 13.07x faster than Lodash

Test Case 16: Set (unequal) fastIsEqual: 0.000070 ms Lodash isEqual: 0.000930 ms Difference (fastIsEqual - Lodash): -0.000860 ms fastIsEqual is 13.22x faster than Lodash

Test Case 17: Empty Object vs Array fastIsEqual: 0.000009 ms Lodash isEqual: 0.000043 ms Difference (fastIsEqual - Lodash): -0.000034 ms fastIsEqual is 4.74x faster than Lodash

Test Case 18: Map vs Set fastIsEqual: 0.000018 ms Lodash isEqual: 0.000469 ms Difference (fastIsEqual - Lodash): -0.000452 ms fastIsEqual is 26.55x faster than Lodash

Average Performance: fastIsEqual: 0.000063 ms Lodash isEqual: 0.000483 ms fastIsEqual is on average 7.71x faster than Lodash

## License
MIT

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