Benchmark: arty lodash.isEqual vs fast-deep-equal

HTML Preparation code:

<script src="https://cdn.jsdelivr.net/npm/lodash@4.17.20/lodash.min.js"></script>

Script Preparation code:

function equal(a, b) {
  if (a === b) return true;

  if (a && b && typeof a == 'object' && typeof b == 'object') {
    if (a.constructor !== b.constructor) return false;

    var length, i, keys;
    if (Array.isArray(a)) {
      length = a.length;
      if (length != b.length) return false;
      for (i = length; i-- !== 0;)
        if (!equal(a[i], b[i])) return false;
      return true;
    }



    if (a.constructor === RegExp) return a.source === b.source && a.flags === b.flags;
    if (a.valueOf !== Object.prototype.valueOf) return a.valueOf() === b.valueOf();
    if (a.toString !== Object.prototype.toString) return a.toString() === b.toString();

    keys = Object.keys(a);
    length = keys.length;
    if (length !== Object.keys(b).length) return false;

    for (i = length; i-- !== 0;)
      if (!Object.prototype.hasOwnProperty.call(b, keys[i])) return false;

    for (i = length; i-- !== 0;) {
      var key = keys[i];

      if (!equal(a[key], b[key])) return false;
    }

    return true;
  }

  // true if both NaN, false otherwise
  return a!==a && b!==b;
};

                
// 1 level deep
var excludedProps = [
	'prop4', 'prop6',
];
var data = [
                    {
                        description: 'equal numbers',
                        value1: 1,
                        value2: 1,
                        equal: true,
                    },
                    {
                        description: 'not equal numbers',
                        value1: 1,
                        value2: 2,
                        equal: false,
                    },
                    {
                        description: 'number and array are not equal',
                        value1: 1,
                        value2: [],
                        equal: false,
                    },
                    {
                        description: '0 and null are not equal',
                        value1: 0,
                        value2: null,
                        equal: false,
                    },
                    {
                        description: 'equal strings',
                        value1: 'a',
                        value2: 'a',
                        equal: true,
                    },
                    {
                        description: 'big object',
                        value1: {
                            prop1: 'value1',
                            prop2: 'value2',
                            prop3: 'value3',
                            prop4: {
                                subProp1: 'sub value1',
                                subProp2: {
                                    subSubProp1: 'sub sub value1',
                                    subSubProp2: [
                                        1,
                                        2,
                                        { prop2: 1, prop: 2 },
                                        4,
                                        5,
                                    ],
                                },
                            },
                            prop5: 1000,
                            prop6: new Date(2016, 2, 10),
                        },
                        value2: {
                            prop5: 1000,
                            prop3: 'value3',
                            prop1: 'value1',
                            prop2: 'value2',
                            prop6: new Date('2016/03/10'),
                            prop4: {
                                subProp2: {
                                    subSubProp1: 'sub sub value1',
                                    subSubProp2: [
                                        1,
                                        2,
                                        { prop2: 1, prop: 2 },
                                        4,
                                        5,
                                    ],
                                },
                                subProp1: 'sub value1',
                            },
                        },
                        equal: true,
                    },
                ];

Tests:

lodash
data.forEach((item) => { _.isEqual( _.omit(item.value1,excludedProps), _.omit(item.value2,excludedProps)); });
fast-deep-equal
data.forEach((item) => { equal(item.value1, item.value2, excludedProps); });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
lodash
fast-deep-equal

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

I'll break down the benchmark definition and explain what's being tested, compared, and their pros/cons.

**Benchmark Definition**

The benchmark is testing two functions: `_.isEqual` from the Lodash library and `fast-deep-equal`. Both functions are used to compare two objects for equality.

**What is tested?**

* The test case consists of 7 individual test cases (`data.forEach`) that iterate over an array of objects.
* Each object has two properties (`value1` and `value2`) with different values, including numbers, arrays, null, and dates.
* The benchmark tests the performance of both `_.isEqual` and `fast-deep-equal` functions to compare these two objects.

**Options compared**

The benchmark compares two options:

1. **Lodash's _.isEqual**: A widely-used library function that recursively checks for deep equality between objects.
2. **fast-deep-equal**: A custom implementation of deep equality checking, likely optimized for performance.

**Pros and Cons of each approach**

**_.isEqual (Lodash)**

Pros:

* Wide adoption and familiarity in the developer community
* Handles various edge cases, such as NaNs, dates, and null/undefined values
* Well-tested and stable

Cons:

* May be slower than custom implementations due to overhead of library functions
* Additional dependency on Lodash library

**fast-deep-equal**

Pros:

* Optimized for performance, potentially faster execution
* No additional dependencies or library overhead

Cons:

* May not handle all edge cases as thoroughly as _.isEqual
* Requires manual implementation and testing to ensure correctness

**Other considerations**

* The benchmark uses a custom `equal` function that simply checks for reference equality (`a === b`). This is likely done to isolate the performance difference between `_._isEqual` and `fast-deep-equal`.
* The `excludedProps` array defines which properties are ignored during comparison. Both functions use this array, but `_.isEqual` also uses a more comprehensive approach to ignore properties.

**Alternatives**

Other alternatives for deep equality checking include:

* JSON.stringify() + === (a simple, but not optimized, approach)
* deep-equal-js (another lightweight implementation)
* Recurse.js (a recursive function for checking equality)

Note that these alternatives might have different performance characteristics and may require additional considerations.

The benchmark result shows the performance difference between `fast-deep-equal` and `_._isEqual`, with `fast-deep-equal` outperforming Lodash's implementation.

Related benchmarks:

arty lodash.isEqual vs fast-deep-equal (version: 0)

Comparing performance of: lodash vs fast-deep-equal

Created: 2 years ago by: Guest

Jump to the latest result

lodash

fast-deep-equal

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):