Benchmark: conditional spread vs conditional mutate

Tests:

conditional spread
const conditionallyAdd = (yes) => { return { something: 1, ...(yes ? { somethingAdded: 2 } : {}) } } conditionallyAdd(true) conditionallyAdd(false)
conditional mutation
const conditionallyMutate = (yes) => { const ret = { something: 1 } if (yes) ret.somethingAdded = 2 return ret } conditionallyMutate(true) conditionallyMutate(false)

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Test case name	Result
conditional spread
conditional mutation

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Slowest: N/A

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

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Let's dive into the world of JavaScript microbenchmarks.

The provided JSON represents two benchmark test cases: "conditional spread" and "conditional mutation". Both tests aim to measure the performance differences between two approaches: using the spread operator (`...`) or conditional mutation.

**Conditional Spread**

In the "conditional spread" test case, a function `conditionallyAdd` is defined. This function returns an object with a key-value pair `"something": 1`. The twist comes when the `yes` parameter is true; in this case, another key-value pair `{"somethingAdded": 2}` is added to the original object using the spread operator (`...`). If `yes` is false, no new properties are added.

The code:
```javascript
const conditionallyAdd = (yes) => {
  return {
    something: 1,
    ...(yes ? { somethingAdded: 2 } : {})
  }
}
```
**Conditional Mutation**

In the "conditional mutation" test case, a function `conditionallyMutate` is defined. This function returns an object with a key-value pair `"something": 1`. If the `yes` parameter is true, a new property `somethingAdded` is added to the original object using conditional statement (`if (yes)`). If `yes` is false, no new properties are added.

The code:
```javascript
const conditionallyMutate = (yes) => {
  const ret = { something: 1 }
  if (yes)
    ret.somethingAdded = 2
  return ret
}
```
**Options Comparison**

Here's a brief comparison of the two approaches:

* **Spread Operator (`...`)**:
	+ Pros:
		- More concise and readable code.
		- Easier to add new properties dynamically.
	+ Cons:
		- Can be slower due to the overhead of creating a new object.
		- May incur additional memory allocations.
* **Conditional Mutation**:
	+ Pros:
		- Often faster due to fewer object creations.
		- More predictable behavior for those familiar with the syntax.
	+ Cons:
		- Less concise and more verbose code.
		- More prone to errors, especially when dealing with nested objects.

In general, if readability is more important than performance, the spread operator might be a better choice. However, in cases where every millisecond counts, conditional mutation could provide a slight performance advantage.

**Library Considerations**

None of the provided test cases rely on external libraries or frameworks.

**Special JS Features/Syntax**

There are no special JavaScript features or syntax used in these benchmarks. The code is straightforward and uses standard ES6 syntax.

**Other Alternatives**

If you're looking for alternative approaches, consider:

* **Object Assign**: Instead of using the spread operator, you can use `Object.assign()` to create a new object with updated properties.
```javascript
const conditionallyAdd = (yes) => {
  const ret = { something: 1 };
  if (yes)
    Object.assign(ret, { somethingAdded: 2 });
  return ret;
}
```
* **Merge Objects**: You can use the `merge` function from libraries like Lodash or a custom implementation to merge objects with updated properties.
```javascript
const _ = require('lodash');

Related benchmarks:

conditional spread vs conditional mutate (version: 0)

Comparing performance of: conditional spread vs conditional mutation

Created: 3 years ago by: Guest

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conditional spread

conditional mutation

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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