Sinon.JS VS webpack

If you are using a mocking library, such as sinon, jest-mock, or ts-mockito, make sure that it is compatible with Jest. You may need to install additional packages or configure them in your configuration file. For example, to use sinon with Jest, you can install the sinon-jest package and add the following to your configuration file:

Mocha is a test runner, Chai is an assertion library, Sinon is a mocking library, this normally the combination you would need to use if you choose mocha, but there are others.

Instead, use pure functions + dependency inject your stubs (e.g. parameter to function). Also note, no need for Sinon or some other test double library. JavaScript is so good nowadays to easily make objects/classes/functions or any combination thereof on the fly that are terse.

I've had some good experiences with Ava + Sinon. I've personally disliked Jest because it seemed to do some weird trickery in the background that prevented me from using ES modules.

🤖 You can use the Mocha testing framework with the Chai assertion library to write tests for your Express controller. You can also use the Sinon library to mock the database calls. This will allow you to test the controller without actually making a call to the database. You can also use the SuperTest library to make HTTP requests to the controller and test the response.

You can use sinon js to create a mock version of your http library (axios) that responds with the data you’re expecting.

Assertions are the checkpoints of our test block that confirm if an automated test has passed or failed. Cypress bundles the Chai, jQuery, and Sinon.JS libraries for assertions. They check the desired, expected application in which the test is running. A complete listing of assertions can be found in the documentation here.

ES module is basically a "class" that you inject dependencies into through imports. And for tests you just use something like sinon to swap module dependencies for mocks.

You can use a tool like sinon to pass in your own function instead of the real moment library. From there you can write tests that ensure moment was invoked appropriately.

Let's configure tests with mocha, chai and sinon on Typescript in a few steps.

There are various tools available that manage the size of bundled assets. We are going to use the example of a popular and widely used bundler named Webpack, and practically look at many of the optimization techniques it offers.

Homepage: https://webpack.js.org/

Click "Start Test." WebPageTest generates a comprehensive report with details about the loading process, including time to first byte (TTFB), page load time, and visual progress. ### Setting Benchmarks with Lighthouse Start with Lighthouse audits to maximize the performance of your React application. Evaluate Lighthouse's scores and suggestions with careful consideration. Next, set benchmarks that are in line with industry norms or customized to meet your unique performance goals. Lastly, pay close attention to the places in your application where it needs work. You can improve your React application's effectiveness by carefully following these procedures, which will guarantee that it satisfies the required performance requirements. ### Analyzing Performance Results with WebPageTest In order to fully evaluate your webpage's performance, launch WebPageTest with a variety of systems, simulating a variety of user scenarios. Examine the waterfall chart carefully to identify loading patterns and bottlenecks, which are essential for improving the user experience. To see the page's rendering process over time and do a thorough examination, use filmstrip views. To effectively assess performance, pay special attention to measures such as time to first byte (TTFB), start render time, and fully loaded time. Also, a better understanding of performance variances is made possible by comparing findings across various test designs, which helps make well-informed recommendations for improving webpage responsiveness and efficiency. ## Impact of third-party libraries on React app performance Third-party library integration can speed up development while improving functionality in our React application. It's crucial to consider the possible effects on performance, though. Because heavy or poorly optimized libraries might negatively impact the speed and usability of our application. ### Bundle Size Look at the distribution file sizes related to the library, and use tools such as Bundlephobia or Webpack Bundle Analyzer to fully evaluate their impact on your bundle size. This thorough analysis enables you to make well-informed decisions about whether to include the library, making sure that its contribution minimizes superfluous bulk in your application's codebase and is in line with your optimization goals. ### Network Requests Analyze how the third-party library affects network requests to maximize performance. Reduce the number of requests made overall by minimizing external dependencies. This will enhance the user experience and loading speeds. Select appropriate libraries, maximize asset delivery, and leverage code splitting to load components asynchronously. You may improve the effectiveness and responsiveness of your application and provide users with a better experience by cutting down on pointless network queries. ### Execution Time Examine the library's code for any possible performance problems or bottlenecks in order to analyze the runtime performance of the library. Look for places where the code may execute slowly or inefficiently. You may ensure smoother operation inside your application by identifying and addressing any areas of the library's implementation that may be impeding ideal performance by doing a comprehensive assessment. ### Code Splitting for Third-Party Libraries Implementing code splitting is an effective strategy to load third-party libraries only when they are required, reducing the initial page load time. Use dynamic imports to load the library lazily:

Thanks for the thorough answer!

I confess I wasn't thinking about a particular build tool. My recent experience has been with Vite, where I took a similar approach to what you describe, but haven't had to dig deep into bundle performance because that's not a bottleneck for our application. The last time I did deeper work on the subject was years ago with Webpack.

I thought Webpack at least did dead-code elimination before splitting things into chunks. If I'm reading this random GitHub issue[1] right (and the asker is also right), Webpack does partially behave as I expected, but the pre-chunking optimization pass occurs before things like constant expression evaluation.

[1] https://github.com/webpack/webpack/issues/16672

Webpack is a powerful and widely-used module bundler for JavaScript applications. It’s known for its flexibility and extensive plugin system, making it a popular tool in complex web development projects.

Thats all about Webpack Basic, there are lots of feature of webpack, You can check here: https://webpack.js.org/

Many web pages use CSS and JavaScript files to handle various features and styles. Each file, however, requires a separate HTTP request, which can slow down page loading. Concatenation comes into play here. It involves combining multiple CSS or JavaScript files into a single file. As a result, pages load faster, reducing the time spent requesting individual files. Gulp, Grunt, and Webpack are some of the tools that can assist you in speeding up the concatenation process. They enable seamless merging of many files during development, ensuring deployment readiness.

Once you build a simple Vite backend integration, try not to complicate Vite's configuration unless you absolutely must. Vite has become one of the most popular bundlers in the frontend space, but it wasn't the first and it certainly won't be the last. In my 7 years of building for the web, I've used Grunt, Gulp, Webpack, esbuild, and Parcel. Snowpack and Rome came-and-went before I ever had a chance to try them. Bun is vying for the spot of The New Hotness in bundling, Rome has been forked into Biome, and Vercel is building a Rust-based Webpack alternative.

Webpack is a module bundler, the main purpose of which is to bundle JavaScript files to make them usable in a browser.