Benchmark: element matches selector variations

HTML Preparation code:

<main data-bench-element="container"><article data-bench-ignore="true"><hgroup class="attribution"><h1 class="title">Title</h1><h2 data-bench-ignore="true">Subtitle</h2></hgroup></article></main>

Script Preparation code:

var h1 = document.querySelector('h1');
var h2 = document.querySelector('h2');
var article = document.querySelector('article');
var hgroup = document.querySelector('hgroup');

Tests:

class on target element
h1.matches('.title');
data on target element
h2.matches('*[data-bench-ignore]');
data nested star
h1.matches('*[data-bench-ignore], *[data-bench-ignore] *');
less nested star
hgroup.matches('*[data-bench-ignore], *[data-bench-ignore] *');
nested without star
h1.matches('article[data-bench-ignore] h1');
nested selector with tag
document.querySelector('article[data-bench-ignore] h1');
selector all with star data
document.querySelector('*[data-bench-ignore] *');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
class on target element
data on target element
data nested star
less nested star
nested without star
nested selector with tag
selector all with star data

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Measuring performance of JavaScript queries is crucial in web development, and MeasureThat.net provides an excellent platform for this purpose.

The provided benchmark tests the performance of the `matches()` method in JavaScript, which is used to query an element based on a CSS selector or attribute. The test cases cover various scenarios, including:

1. **Selector patterns**: The first three test cases (`class on target element`, `data on target element`, and `less nested star`) focus on different types of selectors (class, data attribute, and less nested star). These tests measure the performance of the `matches()` method with varying levels of nesting.
2. **Nested queries**: The next two test cases (`nested without star` and `nested selector with tag`) introduce nested queries, which require the browser to evaluate multiple CSS selectors in a single operation. This adds complexity to the query, making it more challenging for the browser's engine to optimize.
3. **All-star selector**: The last two test cases (`selector all with star data` and its variants) focus on selecting all elements that match a specific attribute (in this case, `data-bench-ignore`). These tests measure the performance of the `matches()` method when dealing with complex attribute queries.

Now, let's discuss the pros and cons of each approach:

**Selector patterns:**

* **Pros**: This approach allows for a thorough understanding of how different selector types affect performance. It helps developers identify areas where optimization is necessary.
* **Cons**: Testing individual selector patterns might not provide enough context on how to apply these optimizations in real-world scenarios.

**Nested queries:**

* **Pros**: These tests simulate common use cases, such as querying elements with nested attributes or CSS classes. This helps ensure that the browser's engine can handle complex queries efficiently.
* **Cons**: Nested queries can be computationally expensive, and excessive nesting might lead to performance degradation. MeasureThat.net helps identify optimization strategies for these scenarios.

**All-star selector:**

* **Pros**: These tests help developers understand how attribute selectors work and optimize their code accordingly. This is particularly important when dealing with complex attributes or queries.
* **Cons**: All-star selectors can be computationally expensive, and excessive usage might lead to performance issues. MeasureThat.net helps identify strategies for optimizing these scenarios.

The use of `data-bench-ignore` attribute in the HTML preparation code serves as a mechanism to exclude certain elements from the benchmark results. This allows MeasureThat.net to focus on the performance-critical aspects of the `matches()` method.

MeasureThat.net also skips preambles (unnecessary overhead) by using an immediate function (`(function() { ... })`) to execute the script preparation code and HTML content, which helps eliminate unnecessary computation.

When it comes to special JavaScript features or syntax, MeasureThat.net doesn't explicitly mention any specific features. However, the tests cover various scenarios, including:

* Attribute selectors (`[data-bench-ignore]`)
* CSS classes (`h1`, `h2`)

Other alternatives for measuring performance and optimizing JavaScript queries include:

* **Benchmarking libraries**: Tools like BenchmarkJS, jsperf, or Perfbench provide a framework for creating and running benchmarks.
* **Browser-specific performance tools**: Each browser has its own set of performance tools and extensions that can help identify optimization opportunities. For example:
	+ Chrome DevTools (DevTools) provides advanced profiling and benchmarking capabilities.
	+ Firefox Developer Edition includes the Firefox Web Developer's Toolset, which offers performance analysis and optimization features.
* **CI/CD pipelines**: Integrating performance testing into continuous integration and delivery (CI/CD) pipelines helps ensure that code changes are thoroughly tested for performance issues before deployment.

By using MeasureThat.net in conjunction with these alternatives, developers can gain a deeper understanding of their JavaScript query performance and optimize their code for better results.

Latest run results:

Run details: (Test run date: 8 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36

Browser/OS: Chrome 122 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
class on target element	15563078.0 Ops/sec
data on target element	14964935.0 Ops/sec
data nested star	10984939.0 Ops/sec
less nested star	11903179.0 Ops/sec
nested without star	11525582.0 Ops/sec
nested selector with tag	4988918.5 Ops/sec
selector all with star data	2808924.0 Ops/sec

Related benchmarks:

element matches selector variations (version: 0)

Testing element query and matches against various nesting and selector patterns

Comparing performance of: class on target element vs data on target element vs data nested star vs less nested star vs nested without star vs nested selector with tag vs selector all with star data

Created: 8 months ago by: Registered User

Jump to the latest result

class on target element

data on target element

data nested star

less nested star

nested without star

nested selector with tag

selector all with star data

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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