fast-is-equal

fast-is-equal

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

Why fast-is-equal?

• Lightning Speed: Up to 64.53x faster than Lodash's isEqual (average 13.21x faster across 49 test cases).
• Lightweight: Dependency-free, minimal footprint.
• Versatile: Handles primitives, objects, arrays, Maps, Sets, typed arrays, circular references, and more.
• Proven: Outperforms Lodash in 98% of benchmark cases.

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

Performance Benchmarks

fast-is-equal was tested against Lodash's isEqual across 49 diverse test cases with 1,000,000 iterations each. The results speak for themselves:

Key Highlights

• Average Speed: fastIsEqual is 13.21x faster (0.000147 ms vs. 0.001941 ms).
• Win Rate: Outperforms Lodash in 48/49 cases (98.0%).
• Peak Performance: Up to 64.53x faster for large Sets.

Top 10 Performance Gains

Test Case	fastIsEqual (ms)	Lodash isEqual (ms)	Speed Boost
Large Set (100 items)	0.000585	0.037756	64.53x
Large Map (50 entries)	0.000912	0.025252	27.70x
Map vs Set	0.000018	0.000469	26.45x
ArrayBuffer (small)	0.000068	0.001242	18.40x
Empty Map	0.000037	0.000661	18.04x
Empty Set	0.000037	0.000668	17.96x
Map with primitives	0.000081	0.001405	17.27x
Uint8Array	0.000038	0.000654	17.08x
Map (unequal)	0.000080	0.001316	16.41x
Float32Array	0.000041	0.000652	15.72x

Performance Across Categories

• Primitives: Competitive performance with smart optimizations for edge cases like NaN
• Objects: 1.45x–3.02x faster, with best gains on simple and nested structures
• Arrays: 2.40x–4.06x faster, excelling at primitive arrays and sparse arrays
• TypedArrays: 12.62x–17.08x faster, dramatically outperforming on all variants
• Special Objects: 9.43x–10.95x faster for Dates and RegExp
• Collections: 11.34x–64.53x faster for Maps and Sets, with exceptional gains on large collections
• Circular References: 3.48x–3.87x faster with optimized cycle detection

Detailed Benchmark Results

Run yarn benchmark or npm run benchmark to test locally. Full results available in benchmarks/results.txt.

Edge Cases Where Lodash Wins

Only 1 case where Lodash marginally outperforms:

• Strings: 0.85x slower

This is a ~5-nanosecond comparison at the benchmark's measurement resolution, with negligible real-world impact.

Features

• Dependency-Free: No bloat, just performance.
• Comprehensive: Supports all JavaScript types, including edge cases like circular references and typed arrays.
• Optimized: Fine-tuned for real-world use cases (e.g., API responses, state objects).

License

MIT

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