Let's dive into the world of JavaScript microbenchmarks.

Benchmark Definition

The benchmark is designed to compare two approaches for rendering HTML templates in a browser: innerHTML and insertAdjacentHTML. The benchmark uses the template element, which is a Web Components API that allows creating and manipulating HTML templates.

Script Preparation Code

There is no script preparation code provided for this benchmark. This means that the JavaScript engine will create the template element and assign it to the template variable without any additional setup or initialization code.

Html Preparation Code

Similarly, there is no html preparation code provided for this benchmark. The HTML code for the test case is hard-coded directly into the Benchmark Definition JSON:

const template = document.createElement("template");
template.innerHTML = "<div></div>";

or

const template = document.createElement("template");
template.insertAdjacentHTML("afterbegin", "<div></div>");

Individual Test Cases

There are two test cases in this benchmark:

1. innerHTML: This test case creates a new template element and assigns an HTML string to its innerHTML property.
2. insertAdjacentHTML: This test case also creates a new template element, but instead of assigning an HTML string to its innerHTML property, it uses the insertAdjacentHTML method to insert an HTML fragment into the template.

Library and Purpose

In this benchmark, the Web Components API (template) is used to create and manipulate HTML templates. The template element is a new addition to the Web Components API, introduced in Chrome 85 (released in March 2020).

Special JS Feature or Syntax

The benchmark uses the insertAdjacentHTML method, which was introduced in ECMAScript 2019 (ES11). This method allows inserting HTML fragments into an element without the need for innerHTML or other methods.

Pros and Cons of Different Approaches

1. innerHTML: This approach is widely supported across browsers but can be slower due to the overhead of parsing and sanitizing user-supplied HTML.
   • Pros: Easy to use, well-supported by most browsers.
   • Cons: Can be slow, less efficient than other approaches.
2. insertAdjacentHTML: This approach provides better performance and efficiency compared to innerHTML, as it avoids parsing and sanitizing user-supplied HTML.
   • Pros: Faster, more efficient, and less error-prone.
   • Cons: May not be supported by older browsers.

Other Alternatives

Some other alternatives for rendering HTML templates in a browser include:

1. DOM manipulation: Using traditional DOM methods (e.g., createElement, appendChild) to build and render the HTML template.
2. Shadow DOM: Using Shadow DOM, which allows creating isolated DOM trees that can be used for templating purposes.

However, Web Components API (template) is a popular choice for building reusable UI components and templates due to its simplicity and flexibility.

Additional Considerations

When choosing an approach for rendering HTML templates in a browser, consider factors such as:

1. Browser support: Ensure the chosen approach is supported by your target browsers.
2. Performance: Choose an approach that balances performance with ease of use and maintainability.
3. Security: Be aware of potential security risks associated with user-supplied HTML.

I hope this explanation helps you understand what's being tested in MeasureThat.net!