Benchmark: Lodash isEqual test v4.17.21

HTML Preparation code:

<script src="https://cdn.jsdelivr.net/npm/lodash@4.17.21/lodash.min.js"></script>

Script Preparation code:

// 1 level deep
window.foo1 = { a: 1, b: 2, c: { a: 1, b: 2, c: { a: 1, b: 2 } } };
window.bar1 = { a: 1, b: 3, c: { a: 1, b: 2, c: { a: 1, b: 2 } } };

// 2 levels deep
window.foo2 = { a: 1, b: 2, c: { a: 1, b: 2, c: { a: 1, b: 2 } } };
window.bar2 = { a: 1, b: 2, c: { a: 1, b: 3, c: { a: 1, b: 2 } } };

// 3 levels deep
window.foo3 = { a: 1, b: 2, c: { a: 1, b: 2, c: { a: 1, b: 2 } } };
window.bar3 = { a: 1, b: 2, c: { a: 1, b: 2, c: { a: 1, b: 4 } } };

Tests:

_.isEqual Level 1
_.isEqual(window.foo1, window.bar1)
JSON.stringify Level 1
JSON.stringify(window.foo1) === JSON.stringify(window.bar1);
_.isEqual Level 2
_.isEqual(window.foo2, window.bar2)
JSON.stringify Level 2
JSON.stringify(window.foo2) === JSON.stringify(window.bar2);
_.isEqual Level 3
_.isEqual(window.foo3, window.bar3)
JSON.stringify Level 3
JSON.stringify(window.foo3) === JSON.stringify(window.bar3);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
_.isEqual Level 1
JSON.stringify Level 1
_.isEqual Level 2
JSON.stringify Level 2
_.isEqual Level 3
JSON.stringify Level 3

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/129.0.0.0 Safari/537.36

Browser/OS: Chrome 129 on Windows

View result in a separate tab

Test name	Executions per second
_.isEqual Level 1	1414764.0 Ops/sec
JSON.stringify Level 1	1422227.9 Ops/sec
_.isEqual Level 2	932289.2 Ops/sec
JSON.stringify Level 2	1417328.4 Ops/sec
_.isEqual Level 3	704326.8 Ops/sec
JSON.stringify Level 3	1425330.8 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated 2 months ago):

LLMs can make mistakes. Check important info.

The provided benchmark tests evaluate different methods of comparing deeply nested JavaScript objects for equality. Specifically, it contrasts two approaches: using the Lodash library's `_.isEqual` function and a straightforward comparison using `JSON.stringify`.

### Benchmark Overview

The benchmark is structured around three test cases, each with varying levels of nesting in the JavaScript objects being compared:

1. **Level 1**: Simple comparison with a single level of objects.
2. **Level 2**: Moderate depth with two levels of nested objects.
3. **Level 3**: More complex structure featuring three levels of nested objects.

### Methods Compared

There are two methods that are evaluated for equality:

1. **Lodash's `_.isEqual`**
   - **Description**: This is a utility function from the Lodash library that performs a deep comparison between two values to determine if they are equivalent.
   - **Pros**:
     - Handles many data types effectively, including arrays and objects.
     - Accounts for special cases like NaN or different value types (e.g., different objects, functions).
     - Generally optimized for performance in real-world scenarios.
   - **Cons**:
     - Requires the inclusion of an external library, increasing dependency and potentially bundle size.
     - May not always be as fast for simple cases compared to more direct methods.
 
2. **Simple Comparison using `JSON.stringify`**
   - **Description**: This method serializes both objects into JSON strings and compares the strings for equality.
   - **Pros**:
     - Easy to implement without any external libraries. It's a lightweight approach.
     - Can be fast for simple objects since it leverages built-in JavaScript functionality.
   - **Cons**:
     - Fails for objects containing functions, undefined values, or special values like `NaN`, which will not be serialized accurately.
     - Performance can degrade with complex or deeply nested structures due to the serialization overhead.
     - Order of properties matters; two object literals that differ only in property order will be considered unequal.

### Benchmark Results

The benchmark results show the number of executions per second for each method at varying levels of depth. Here’s a summary:

- **Fastest Execution**: The `JSON.stringify` method achieved higher execution speeds than `_.isEqual` across all levels of nesting, especially noticeable at Level 1 and Level 2.
- **Performance Degradation**: In-depth comparisons (Level 3) showed a marked decrease in performance for `_.isEqual`, indicating that the function struggles more with complex structures, whereas `JSON.stringify` remained consistently more performant but would still be limited by its serialization approach.

### Considerations and Alternatives

Given the differences demonstrated in the benchmark:

- **Alternative Libraries**: Other libraries like [Ramda](https://ramdajs.com/) or [DeepEqual](https://www.npmjs.com/package/deep-equal) can also be used for deep comparisons, each with their own set of trade-offs regarding performance, size, and feature sets.
  
- **Native Solutions**: In scenarios where object structures are not deeply nested and the performance overhead of serialization is acceptable, using `JSON.stringify` can suffice. However, for comprehensive equality checking in production applications, using libraries like Lodash or exploring other specialized libraries would be more robust.

- **When to Use Which**: For quick scripts or prototyping, `JSON.stringify` might be sufficient. For production code dealing with a variety of data types or requiring precise comparison logic, `_.isEqual` or other libraries are recommended.

This benchmarking exercise provides valuable insights into the performance characteristics of these methods and helps guide developers in choosing the right approach for object comparison based on their specific needs.

Related benchmarks:

Lodash isEqual test v4.17.21 (version: 0)

Comparing performance of: _.isEqual Level 1 vs JSON.stringify Level 1 vs _.isEqual Level 2 vs JSON.stringify Level 2 vs _.isEqual Level 3 vs JSON.stringify Level 3

Created: 2 months ago by: Guest

Jump to the latest result

_.isEqual Level 1

JSON.stringify Level 1

_.isEqual Level 2

JSON.stringify Level 2

_.isEqual Level 3

JSON.stringify Level 3

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated 2 months ago):