Benchmark: ternary undefined vs {} with Object.assign via spread operator

Tests:

With empty object
const wrapMode = 'foo'; const foo = { ...(wrapMode === 'withEllipse' ? { textOverflow: 'ellipsis' } : {}), };
With undefined
const wrapMode = 'foo'; const foo = { ...(wrapMode === 'withEllipse' ? { textOverflow: 'ellipsis' } : undefined), };

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
With empty object
With undefined

Fastest: N/A

Slowest: N/A

Latest run results:

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

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

**Benchmark Overview**

The test case measures the performance difference between two approaches:

1. Using an empty object `{}` as the second argument in the spread operator (`...`).
2. Using `undefined` as the second argument in the spread operator (`...`).

**Options Compared**

Two options are being compared:

* **Empty Object `{}`**: When using an empty object as the second argument, the code will only take on properties that are present in the first object (`wrapMode`). This is likely to be a more efficient approach.
* **Undefined `undefined`**: When using `undefined` as the second argument, the code will include all properties from the first object (`wrapMode`), even if they're not needed. This might lead to unnecessary processing and memory usage.

**Pros/Cons**

Using an empty object `{}`:

Pros:

* More efficient, as only necessary properties are taken on.
* Less memory usage, as no unnecessary properties are included.

Cons:

* May require additional checks to ensure that the `wrapMode` property is present before taking it on.
* Might lead to slightly slower startup times due to the need for additional checks.

Using `undefined`:

Pros:

* Easier to implement, as no additional checks are required.
* Faster startup times, as all properties are included upfront.

Cons:

* More memory usage, as unnecessary properties are included.
* Potentially slower performance due to unnecessary processing and property lookups.

**Library and Special JavaScript Features**

There is no specific library mentioned in the benchmark definition or test cases. However, the use of the spread operator (`...`) suggests that modern JavaScript features, specifically `Object.assign` with a spread operator, are being tested.

**Special JavaScript Feature**

The feature being tested is the spread operator (`...`) with `Object.assign`. This allows for more concise and expressive code when merging objects.

**Alternative Approaches**

If an empty object `{}` or `undefined` approach is not suitable, other alternatives could include:

* Using a library like Lodash's `_.merge()` function to merge objects.
* Implementing a custom `merge()` function using `Object.assign()`.
* Using a different data structure, such as a hash map, to store and retrieve properties.

Keep in mind that these alternatives may have their own performance implications and trade-offs.

Related benchmarks:

ternary undefined vs {} with Object.assign via spread operator (version: 0)

Comparing performance of: With empty object vs With undefined

Created: 3 years ago by: Guest

Jump to the latest result

With empty object

With undefined

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):