Benchmark: 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 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(item.value1, item.value2); });
fast-deep-equal
data.forEach((item) => { equal(item.value1, item.value2); });

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:

Run details: (Test run date: 16 days ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/147.0.0.0 Safari/537.36

Browser/OS: Chrome 147 on Linux

View result in a separate tab

Test name	Executions per second
lodash	217183.5 Ops/sec
fast-deep-equal	738061.6 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**Benchmark Definition**

The benchmark measures the performance difference between two JavaScript functions:

1. `lodash.isEqual` (Lodash): A widely-used library for comparing values.
2. `equal` (Custom implementation): A custom function written in JavaScript.

**Test Cases**

There are two test cases:

1. **Lodash (`_.isEqual`)**
The benchmark defines a script that iterates over an array of objects using the `forEach` method and calls `_lodash.isEqual` on each pair of `value1` and `value2` properties.
```javascript
data.forEach((item) => {
  _.isEqual(item.value1, item.value2);
});
```
**Custom Implementation (`equal`)**

The benchmark also defines a script that iterates over the same array of objects using `forEach` and calls the custom `equal` function on each pair of `value1` and `value2` properties.
```javascript
data.forEach((item) => {
  equal(item.value1, item.value2);
});
```
**Comparison**

The benchmark compares the performance of Lodash's `_isEqual` function with the custom implementation (`equal`). This comparison is done by executing both scripts multiple times (not specified in the provided data).

**Pros and Cons**

**Lodash (`_.isEqual`)**

Pros:

* Widely used and maintained library
* Optimized for performance

Cons:

* External dependency on Lodash
* May not be suitable for situations where size matters (e.g., minified versions)

**Custom Implementation (`equal`)**

Pros:

* No external dependencies
* May have benefits when the implementation is optimized specifically for the use case

Cons:

* Requires more effort to maintain and optimize
* May lack the performance optimizations of a well-maintained library like Lodash

**Other Considerations**

The benchmark also includes some additional considerations, such as:

* Using `Array.isArray()` to check if an object is an array or not.
* Handling `NaN` (Not a Number) values using a simple trick (`a !== a && b !== b`).
* Using `Object.keys()` and `Object.prototype.hasOwnProperty.call()` for comparing object properties.

**Alternatives**

If you're considering implementing your own comparison function, you may want to explore other libraries or implementations that offer similar functionality with better performance or features. Some examples include:

* `fast-deep-equal` (not used in this benchmark)
* `deep-eq` (a JavaScript library for deep object equality)
* `compare-arrays` (a polyfill for array comparison)

Keep in mind that the best approach often depends on your specific use case and requirements.

Related benchmarks:

lodash.isEqual vs fast-deep-equal (version: 1)

Comparing performance of: lodash vs fast-deep-equal

Created: 5 years ago by: Registered User

Jump to the latest result

lodash

fast-deep-equal

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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