Benchmark: clone with change

Script Preparation code:

class Holder {
    constructor(init) {
        Holder.internalAssign(this, init);
    }
    static has(instance, property) {
        return Object.prototype.hasOwnProperty.call(instance, property);
    }
    static internalAssign(target, source) {
        if (Holder.has(source, "a"))
            target.a = source.a;
        if (Holder.has(source, "b"))
            target.b = source.b;
        if (Holder.has(source, "c"))
            target.c = source.c;
    }
    clone() {
        return new Holder(this);
    }

    cloneWith(props) {
        const cloned = this.clone();
        Holder.internalAssign(cloned, props);
        return cloned;
    }
    cloneWith2(props) {
        const cloned = this.clone();
        Object.assign(this, props);
        return cloned;
    }

    mutate(mutation) {
        const cloned = this.clone();
        mutation(cloned);
        return cloned;
    }
}

var initHolder = new Holder({
    a: "value of a",
    b: "value of b",
    c: 1
});

Tests:

cloneWith
initHolder.cloneWith({ a: "changed a", b: "changed b" });
cloneWith2
initHolder.cloneWith2({ a: "changed a", b: "changed b" });
mutate
initHolder.mutate(x => { x.a = "changed a"; x.b = "changed b" });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
cloneWith
cloneWith2
mutate

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/94.0.4606.81 Safari/537.36

Browser/OS: Chrome 94 on Windows

View result in a separate tab

Test name	Executions per second
cloneWith	549301.3 Ops/sec
cloneWith2	768467.2 Ops/sec
mutate	1027458.9 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and its test cases.

**Benchmark Definition**

The provided JSON represents a JavaScript microbenchmark that tests the performance of three different methods for cloning and mutating an object: `cloneWith`, `cloneWith2`, and `mutate`.

*   The `clone` method creates a new instance of the `Holder` class, copying all its properties.
*   The `cloneWith` method creates a clone of the original object using `clone()`, and then updates it with new properties using `internalAssign`.
*   The `cloneWith2` method uses `Object.assign()` to update the cloned object with new properties.
*   The `mutate` method clones the original object using `clone()`, applies a transformation function to the clone, and returns the mutated object.

**Options Compared**

The benchmark compares the performance of these three methods:

1.  **`cloneWith`**: Creates a new instance of the `Holder` class, copies all properties, and then updates it with new properties.
2.  **`cloneWith2`**: Uses `Object.assign()` to update the cloned object with new properties.
3.  **`mutate`**: Clones the original object using `clone()`, applies a transformation function to the clone, and returns the mutated object.

**Pros and Cons of Each Approach**

1.  **`cloneWith`**: Pros:
    *   Can be more efficient when updating specific properties.
    *   May have better cache locality due to direct property access.
2    Cons:
    *   Requires an additional `internalAssign()` call, which may incur overhead.
*   **`cloneWith2`**: Pros:
    *   Uses a standard method for updating objects (Object.assign()).
    *   Can be more concise and easier to read.
3  Cons:
    *   May have higher overhead due to the overhead of the `Object.assign()` function.
*   **`mutate`**: Pros:
    *   Simplifies cloning and updating logic into a single method.
    *   May reduce overall object creation and property assignment overhead.
4  Cons:
    *   Requires applying a transformation function, which can be more complex.

**Special Considerations**

In the provided benchmark definition, there is no special JavaScript feature or syntax used beyond what's standard. However, in other scenarios, additional considerations might arise:

*   **ES6 Classes**: The `Holder` class uses ES6 classes, which provide a concise way to define objects and their behavior.
*   **Object Literals**: The benchmark uses object literals (`{}`) for defining objects, which is a standard JavaScript syntax.

**Alternatives**

If you wanted to implement an alternative clone or mutation method in this benchmark, some options could include:

*   Using a library like Lodash or Immutable.js for functional programming and immutable data structures.
*   Implementing a custom cloning or mutation algorithm based on specific requirements or performance characteristics.

Related benchmarks:

clone with change (version: 2)

Comparing performance of: cloneWith vs cloneWith2 vs mutate

Created: 3 years ago by: Registered User

Jump to the latest result

cloneWith

cloneWith2

mutate

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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