Svelte

State of Svelte Wrap-up

Apr 28, 2023

4 min read

In this State of Svelte event, our panelists discussed updates, LTS releases, and APIs, with Node.js maintainers, technical steering committee members, and collaborators.

In this wrap-up, we will take a deeper look into these latest developments, and explore what is on the horizon for Svelte. You can watch the full State of Svelte event on the This Dot Media YouTube Channel.

Here is a complete list of the host and panelists that participated in this online event.

Hosts:

Tracy Lee, CEO, This Dot Labs, @ladyleet
Rob Ocel, Team Lead & Software Architect, @robocell

Panelists:

Scott Spence, Svelte Society, Developer Relations Engineer at Storyblok, @spences10
Brittney Postma, Founder Svelte Sirens & Software Engineer Design Systems at Provi, @BrittneyPostma
Geoff Rich, Senior Software Engineer, Ordergroove | Svelte Core Team, @geoffrich_
Simon Holthausen, Software Engineer at Vercel | Full-time Svelte maintainer, @dummdidumm_
Kevin Åberg Kultalahti, Co-founder & Technical Community Builder at Svelte Society, Main Organizer at Svelte Summit, @kevmodrome

Svelte 4

The chat got off to a great start with a discussion about Svelte 4, and what we can expect with that release. Simon spoke about how it will be more of a maintenance update than anything else.

This version of Svelte will raise the minimum required Node version and use newer versions of Typescript as well. There will also be other minor breaking changes, but the release will mainly be focused on internally updating the repository by converting it to a mono-repo. As soon as these updates are done, Simon said they will immediately begin work on Svelte 5.

Typescript and Svelte

Scott brings up the reasons for not using Typescript in Svelte. Simon said a decision was made to transition the Svelte repository from using Typescript to using Javascript.

There were questions about why types and type safety were being taken away from the repository. Simon clarified that the repository will be getting rid of .TS files, but they are not getting rid of type checking with Typescript, and the code will still be fully typed checked at the same level as before. The plan is to do it through JS Docs.

JS Docs provides the same level of type safety you get through Typescript, but there is no longer a need for a compile step when using JS Docs. There is also no need to ship any Source Maps, and it should be easier to debug.

Kevin also wanted to be clear that Typescript can still be used when building a Svelte app.

Why Svelte?

Rob notes that the official release of Svelte happened about 4 months ago, and asks the panelists how the launch has been going so far.

Kevin goes first, talking about how everyone with whom he has talked about it has been very excited about it. He talks about how the form actions and data loading are very popular. In other frameworks, you have to attach event listeners, and then do the fetching on clients. Svelte simplifies all of that, and allows you to get rid of a lot of code by using the features in Svelte.

Svelte REPL

Kevin talks about the Svelte REPL, and how it plays into why Svelte is getting so big. Svelte isn’t just easy, it’s the fact that it is social in the fact that you can share a REPL and show someone how to do something with Svelte. If you have an issue, you can usually find a solution in the Svelte REPL.

Server and Client

Geoff talks about this aspect of Svelte. He says that they were treated as two separate entities, and there was talk about how to make them more interconnected so that it’s easier to use the server data, and get it into components.

In SvelteKit, you have a load function in a separate file that defines how that data is loaded. Svelte also calls a JSON endpoint and then that component in the JSON data.

State Management

Geoff brings up the simple state management model that Svelte has, and they really don’t want to give that up by implementing too many things like short syntax.

Simon adds that there is no real reason to bloat the syntax in the Svelte files. He doesn’t want the interoperability that Svelte currently offers.

Signals vs Store

A question is brought up about Signals vs Store, and if they are the same. Simon talks more about how they are related, but they are not necessarily the same. He explains that the API for Store is a little more settled right now where the API for Signals is a little more in exploration.

Usability is also different because Signals is more primitive, and everything is composed of functions which you call in a certain way. With Stores, you wrap a store and map the values that are pushed into something different.

How the panelists found out about Svelte

The latter part of this event focused on how each panelist found Svelte and got involved with it. It was a very interesting part of the conversation to hear the backgrounds of each panelist, and why they got more and more involved with Svelte and everything that was going with it. It went very in depth, and would be worth exploring more by watching the conversation unfold on the event video.

Conclusion

The panelists were very engaged, and there was a lot of dialogue about Svelte and the exciting things being done. The panelists also finished by bringing up ways to get involved with the Svelte community. You can watch the full State of Svelte event on the This Dot Media Youtube Channel.

This Dot is a consultancy dedicated to guiding companies through their modernization and digital transformation journeys. Specializing in replatforming, modernizing, and launching new initiatives, we stand out by taking true ownership of your engineering projects.

We love helping teams with projects that have missed their deadlines or helping keep your strategic digital initiatives on course. Check out our case studies and our clients that trust us with their engineering.

Bruce Wiggleston

@brucerw3 @BruceRW3

Introducing the All New SvelteKit and SCSS Kit for starter.dev

Introduction At This Dot Labs, we love Svelte. We've even created a starter.dev kit for SvelteKit that you can use to scaffold your next frontend project using SCSS, TypeScript, Vitest and Storybook. What is starter.dev? Starter.dev helps developers get started building web apps with a variety of frameworks, showcasing how various libraries can fit together to solve similar problems. To do that, This Dot Labs has built a series of showcase apps that recreate the experience of using GitHub. What is SvelteKit? How is it unique? SvelteKit is a full-stack framework that gives you the best of both worlds: the page is server-side rendered on your first visit, but when you navigate to other pages, they are client-side rendered. SvelteKit gives you levers for your pages to use SSR (server-side rendering), CSR (client-side rendering), SSG (static site generation), SPA (single page application) & MPA (multi page application). The core of SvelteKit provides a highly configurable rendering engine. Why SvelteKit and not Svelte? SvelteKit isn’t built on top of Svelte, but it’s a backend web framework where Svelte is used as the view layer. In theory, you could rip it out and replace it with another component framework that supports server-side rendering, and the same is true for other web frameworks. This allows us to deploy everything as a Node server, or even use Vercel and serverless functions. Other reasons to use SvelteKit include: 1. Pages (file based routing) 2. Endpoints (API routes) 3. Nested layouts (way more powerful than just nesting files because the segment of the URL maps to your component hierarchy) 4. Hot module replacement (instant updates in the browser when you make a change preserving application state) 5. Preprocessing (TypeScript, SCSS, and Pug among others) 6. Building component libraries (creating and publishing npm packages) 7. Deployment options (adapters for any platform) Building a SvelteKit showcase presented several challenges given its uniqueness and different approach to building web apps. This blog post details what we chose to include in our SvelteKit GitHub clone, and how we integrated them. Project Structures and Naming Conventions SvelteKit has unique conventions in its project structure and naming conventions. Project Files src This is the meat of the project: - lib contains your library code, which can be imported via the $lib alias, or packaged up for distribution using svelte-package. It can be imported by using the $lib/* alias. - server contains your server-only library code. SvelteKit will prevent you from importing these in client code. - components contain single responsibility components that are imported in our routes. They typically contain three files: .spec.ts for unit tests, .svelte and .stories.ts for storybook stories. Barrel files were not necessary here. - images contains images that can be imported, and used in the project. - stores contains state that needs to be accessed by multiple unrelated components, or by a regular JS module. - styles contains styles that can be imported in our Svelte applications. - params contains any param matchers your app needs - routes contains the routes of your application - app.html is your page template — an HTML document containing the following placeholders: - %sveltekit.head% — link and script elements needed by the app, plus any head content - %sveltekit.body% — the markup for a rendered page. This should live inside a or other element, rather than directly inside the body element, to prevent bugs caused by browser extensions injecting elements that are then destroyed by the hydration process. SvelteKit will warn you in development if this is not the case - %sveltekit.assets% — either paths.assets, if specified, or a relative path to paths.base - %sveltekit.nonce% — a CSP nonce for manually included links and scripts, if used - hooks.server.ts contains your application's hooks static Any static assets that should be served as-is, like robots.txt or favicon.png, go in here. svelte.config.js This file contains your Svelte and SvelteKit configuration. tsconfig.json Since SvelteKit relies on certain configuration being set a specific way, it generates its own .svelte-kit/tsconfig.json file, which your own config extends. vite.config.js A SvelteKit project is really just a Vite project that uses the @sveltejs/kit/vite plugin, along with any other Vite configuration. Routing To get a deep dive of how routing works with SvelteKit, please check out this article. SCSS SvelteKit supports a number of CSS preprocessors. For people who are new to Svelte or SvelteKit, the syntax for using SCSS or SASS is simple, just need to add the lang="sass" attribute to the style tag. ` ` Then add SCSS support with the svelte-preprocess package. ` Why SCSS and not Tailwind? Tailwind CSS has been used by several other starter kits. We otherwise decided to go with SCSS as the syntax is simple and easily understood by even beginners. Vitest Test Driven Development (TDD) is one of the best ways to ensure your code works like it's supposed to work. It can also help you create reliable builds during continuous deployments. Vitest is an up-and-coming testing framework which has similar functionality to Jest. Since we are using Vite as our build tool for Svelte in this kit, Vitest has very good integration with Vite, and offers a similar testing environment without needing extra configuration. To test Svelte components that seemed to be hard to test. Such as two-way bindings, name slots, Context API, etc., we need to add more configuration. We added @testing-library/svelte, jsdom and @testing-library/jest-dom that allow for similar functionality as Jest. ` We ensured the $lib alias is supported in our tests by resolving the alias in our vite.config.ts. We also added a setupTest.ts to add @testing-library/jest-dom matchers & mocks of SvelteKit modules. ` ` If you want to see some test recipes you can use on your SvelteKit projects, check out our SvelteKit-SCSS Github showcase. Storybook Like many of the other starter.dev kits, the SvelteKit starter uses Storybook to interactively view and build components in isolation. For more information on Storybook and SvelteKit visit the article. Linting ESLint and Prettier are useful tools for keeping the project neat and consistent among multiple contributors. To quickly format your project, run: ` Running ESLint and Prettier as part of your git workflow is important because it helps you fail fast. This helps us, as contributors, to have a more consistent production codebase. We achieved this in our SvelteKit-SCSS Github showcase with the help of Husky, lint-staged and Prettier. How does lint-staged work? It's specifically designed to work on "staged" files, which are files you've changed or created, but haven't yet committed to your project. Working on staged files limits the number of files you need to lint at any given time, and makes the workflow faster. We configured lint-staged in our package.json. This runs Prettier pre-commit, and ensures the code is up to our ESLint standards. ` The commands you configure will run "pre-commit". As you're attempting to commit files to your project you'll see ESLint run in your terminal. Once it's done you may have successfully committed, or find yourself with linting errors you need to fix before you're able to commit the code. This works hand-in-hand with husky. Husky uses distinct bash files with filenames that match the workflow step they correspond to, e.g. "pre-commit". ` Running ESLint, or Prettier as part of your git workflow is important because it helps you fail fast, which helps contributors have a more consistent production codebase. Conclusion SvelteKit is a relatively new and novel framework. The structure represents our best judgment of how a basic SvelteKit application should be. We welcome everyone to take a look, and contribute back to the SvelteKit-SCSS and our SvelteKit-SCSS Github showcase if you have any improvements that you would like to propose!...

Apr 12, 2023

7 mins

SvelteCSS

Svelte 4: Unveiled Speed Enhancements and Developer-Centric Features

Svelte 4: Unveiled Speed Enhancements and Developer-Centric Features Svelte, a widely favored framework for building user interfaces, unveiled its much-anticipated version 4 on June 22. This major release, while paving the way for future advancements, brings a plethora of remarkable enhancements. Focusing on enriching the development experience and boosting performance, Svelte 4 is indeed reshaping the landscape of frontend development. In this post, we'll delve into the specifics of this exciting release, covering the significant performance boosts, enriched developer tools and features, revamped websites, and simplified migration guide. A Deeper Look at Performance Enhancements Svelte 4 delivers remarkable improvements in performance, focusing on shrinking the Svelte package size, and enhancing hydration efficiency. Streamlined Svelte Package Svelte 4 has substantially slimmed down, reducing its overall package size from 10.6 MB to a sleek 2.8 MB - a 75% decrease. This reduction in dependencies from 61 to 16 not only lightens Svelte but also optimizes SvelteKit, significantly accelerating the REPL experience and npm install times. For instance, npm install times have been trimmed from over 5 minutes to less than a minute, a leap in quality that any developer will appreciate. NPM I Before: NPM I After: Bundle Size Before: Bundle Size After: Optimized Hydration and Performance Scores Alongside the impressive package size reduction, Svelte 4 offers more efficient code hydration, reducing the generated code size for the SvelteKit website by nearly 13%. This leaner codebase contributes to higher performance on benchmarks like Google Lighthouse. The performance score for the new Svelte 4 starter on starter.dev has soared from 75% to a near perfect 95+%. Overall, the performance enhancements introduced with Svelte 4 mean a faster, more efficient, and smoother developer experience. Before: After: Enhanced Developer Experience in Svelte 4 Localized Transitions Transitions in Svelte 4 are local by default, preventing potential conflicts during page loading. ` Improved Web Component Authoring Web Components authoring is simplified with the dedicated customElement attribute in svelte:options. ` Stricter Type Enforcement Svelte 4 introduces stricter types for createEventDispatcher, Action, ActionReturn, and onMount. ` These changes collectively offer a streamlined, robust, and efficient coding experience. Revamped Svelte Websites With Svelte 4, the team has also revamped its main website, offering an improved and more user-friendly experience. The Tutorial Website The Svelte tutorial website has been overhauled for an enhanced learning journey. New improvements include a visible file structure, fewer elements in the navbar, smoother navigation between sections, and a new dark mode. The Svelte Website The primary Svelte website received a makeover too, including better mobile navigation, improved TypeScript documentation, and a handy dark mode. These website updates aim to provide a more engaging, intuitive, and user-friendly experience for all Svelte users. A Smooth Migration to Svelte 4 Transitioning from Svelte 3 to Svelte 4 is designed to be as straightforward as possible. The Svelte team has provided an updated migration tool to simplify this process. Here is a step-by-step guide for the transition: 1. Run the Svelte migration tool. ` 2. Remove Svelte 3 packages. ` 3. Update your eslintrc.json configuration file. ` 4. Upgrade Storybook related packages to the latest v7. Note: as of the publishing of this article, the latest version is 7.0.26. ` Do note that the minimum version requirements have changed. You will now need: - NodeJS 16 or higher - SvelteKit 1.20.4 or higher - TypeScript 5 or higher For more detailed instructions and information, please refer to the official Svelte 4 migration guide or you can take a look at our Svelte 4 starter kit on starter.dev. The focus is to ensure a hassle-free transition, allowing developers to take advantage of the new features and enhancements Svelte 4 offers without significant obstacles. Conclusion Svelte 4, with its performance enhancements and streamlined development process, offers a new pinnacle in the realm of JavaScript frameworks. If you're keen on shifting from Svelte 3 to Svelte 4, a comprehensive migration guide is provided to facilitate a smooth transition. For a quick start with Svelte 4, check out our ready-to-use Svelte Kit with SCSS Starter Kit. In addition, we've developed two showcases demonstrating Svelte 4's power: 1. Svelte Kit with SCSS & 7GUIs - A comprehensive demo showcasing various UI challenges. 2. GitHub Replica Showcase - A clone of the popular code hosting platform, GitHub, demonstrating the potential of Svelte 4 in building complex and high-performance web applications. In conclusion, Svelte 4 brings numerous performance improvements and enriches the development experience, thereby increasing developer productivity and enabling the creation of more efficient applications. Its thoughtful design, alongside the streamlined migration process, is set to expand its adoption in the web development community....

Jul 26, 2023

5 mins

Svelte

State of RxJS Wrap-up

In this State of RxJS event, our panelists discussed the current state of RxJS and the upcoming features and improvements of the highly anticipated RxJS 8 release. In this wrap-up, we will talk about panel discussions with RxJS core team members, which is an in-depth exploration of the upcoming RxJS 8 release, highlighting its key features and performance enhancements. You can watch the full State of RxJS event on the This Dot Media YouTube Channel. Here is a complete list of the host and panelists that participated in this online event. Hosts: - Tracy Lee, CEO, This Dot Labs, @ladyleet - Ben Lesh, RxJs Core Team Lead, @BenLesh Panelists: - Mladen Jakovljević, Frontend Web Developer, RxJS Core Team member, @jakovljeviMla - Moshe Kolodny, Senior Full Stack Engineer at Netflix, Previous RxJS Lead at Google, @mkldny - Marko Stanimirović, NgRx Core Team Member | GDE in Angular, @MarkoStDev State of RxJS Ben kicks off the discussion by updating everyone on the current state of RxJS. He starts off by recommending those using RxJS v6 to update to the current version 7.4 because it is about half the size of v6, and he says that v8 will reduce the size even further. There are also performance updates with 7.4 where the speeds improved 30 fold. RxJS version 8 is currently in alpha! There are not as many breaking changes with this version. The major breaking change in this version is that they are removing the long deprecated APIs. They are really wanting people to try things in the alpha version, especially the 408 loops to subscribe to observables. It is an interesting way to consume observables that use the platform, and may work really well with other people’s async await usage. Operators The team is currently trying to figure out a way to show people how they develop operators by giving them the means of developing operators. They currently have a problem where they externally tell people to develop an operator with this, you subscribe, and then you give this kind of hand rolled Observer there. Internally, they have a createOperatorSubscriber which replaces the operate function. They want a reference where you can see how to develop an operator using the ones already there to build your own. There is also a plan to make sure that the RxJS library works as a utility library to work with any Observable that matches the contract. Docs Mladen gives an update of the docs for RxJS. He explains that there aren’t a lot of updates currently with the docs. He explains that there were some issues in the past with exporting operators from two places. There was also an issue with the Docs app build running in the pipeline. He explains that these issues should now be resolved, and that there hopefully won’t be any more issues there. Pull requests are always welcome when working with RxJS docs. They try to stay on top of merge requests as well. NgRx Marko talks about NgRx and RxJS. He explains that RxJS is the main engine of NgRx for almost all of the libraries, especially State Management. A few packages, like direct store, implements a Redux pattern, but uses RxJS under the hood. Pipe Moshe brings up the typings for pipe. All of RxJS’s pipe methods and functions, including the new RxJS function, will work with any unary function. General Questions One of the first questions brought up was if RxJS should not be associated with Angular anymore. Ben brings up the fact that recently, there have been a lot of React people downloading RxJS. Another question was why NgRx is switching to Signals. Marco talks about how NgRx is a group of libraries that is used in Angular. NgRx needs to be in accordance with Angular. One main reason is because of the performance improvements with the change detection strategy. There were also other questions about contributing to RxJS and coming up with a way to utilize the docs for that. There are also questions about the RxJS community, and that there currently isn’t a discord or anything like that for it right now. Conclusion The panelists were very engaged, and there was a lot of dialogue about RxJS and the future that is to come with it. The question and answer portion at the end covered some great material that all the panelists took part in answering. You can watch the full State of RxJS event on the This Dot Media Youtube Channel....

May 22, 2023

4 mins

RxJS

The Future of JavaScript Package Handling and Open Source with Darcy Clarke

Darcy Clarke shares his thoughts on package distribution, open-source sustainability, and vlt.sh, a new package manager which he has been building with npm Creator Isaac Schlueter and Node TSC member Ruy Adorno. This conversation with Tracy Lee, Adam Rackis, and Ben Lesh sheds light on the challenges faced by developers, the imperative for enhanced tools, and the significance of collaboration and innovation within the community. Darcy Clarke pressed the need for simplified package authoring, advocating for improved tools within the JavaScript ecosystem to streamline processes and boost developer productivity. He underscored the hurdles encountered by package authors and the potential for innovation in this domain. As JavaScript continues, the need for efficient package distribution and management tools becomes increasingly paramount. Download this episode here....

Apr 12, 2024

1 min

Engineering Leadership

State of Svelte Wrap-up

Svelte 4

Typescript and Svelte

Why Svelte?

Svelte REPL

Server and Client

State Management

Signals vs Store

How the panelists found out about Svelte

Conclusion

Bruce Wiggleston

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