TypeScript 4.4 Cheat Sheet
SitePen Engineering | October 18, 2021
This cheat sheet is an adjunct to our Definitive TypeScript Guide. Originally published November 2018. Updated October 2021 for TypeScript 4.4.
This cheat sheet is an adjunct to our Definitive TypeScript Guide. Originally published November 2018. Updated October 2021 for TypeScript 4.4.
When developing web applications, choosing a UI component library is one of the earliest decisions your team has to make. Beyond reducing the amount of functionality your team has to maintain, UI component libraries shield developers from the complexities involved in designing user interactions that are accessible and behave correctly across browsers and devices.
What is Machine Learning? Machine learning is a subset of AI that is concerned with algorithms that can improve through experience. Experience in this case generally translates to being fed lots of data. What’s more interesting than what machine learning is though, is what it can do.
Originally published November 2018. Updated June 2020. This article describes the features and functionality of TypeScript 4.2. While TypeScript is very simple to understand when performing basic tasks, having a deeper understanding of how its type system works is critical to unlocking advanced language functionality.
The recent TypeScript 3.9 release primarily focuses on performance and stability, but it does include some language updates that are worth a closer look. Expansion of uncalled function checks Continuing its quest to save you from yourself, TypeScript 3.9 expands on the uncalled function checks that were introduced in version 3.7.
Intern has always taken a different path in the pursuit of flexible automated web app testing. In the early days, Intern leveraged AMD modules when most other testing frameworks were not modular or only supported CommonJS modules, allowing Intern to support modular code in any environment.
HalfStack is a series of tech conferences focused on half of the web development stack – specifically, the part you interface with.
With the boom of location-based technologies like mobile location services and the Geolocation API in the browser, we have seen the growth of mapping and location inside of applications. Alongside this we have seen numerous mapping libraries appear for the web, allowing developers to build map based experiences into their apps.
Rendering large data sets in the browser while optimizing for performance and accessibility is a complex problem. The current approach to handling long lists of data is using an infinite scroll pattern to incrementally load and render data just before the data enters the view.
If you need to build a desktop application today, Electron is an increasingly common choice. It is cross-platform and is built using the same web technologies that you probably already know. We’re long-time users of Electron at SitePen, and have previously talked about Setting up Electron with Dojo.
So you’ve built an amazing app using Dojo and now you are ready to go live. After a bit of research, you learn that traditional deployments are challenging! Luckily, the days of FTPing files are long gone, and we can rely on Docker for fast, reliable deployments.
Augmented Reality (AR) brings digital information or media and interweaves it with our experience of the real-world. In recent years Augmented Reality has become apparent in the consumer space in two major formats: head mounted displays such as the Microsoft HoloLens and the Magic Leap along with more widely available experiences on mobile devices.
One common complaint around web applications is that they can feel slow or clunky compared with native applications. Sometimes we find sites that can take a long time to load (let’s say longer than 3 seconds) and sometimes those sites feel non-interactive or ‘janky’ when we try to interact with them.
SitePen participates in a number of conferences around the world presenting new technology and ideas to engineers and designers. Recently Dylan Schiemann and Tom Dye spoke at the HalfStack Conference in London and Paul Shannon spoke at Phoenix TypeScript meetup.
WebAssembly has grown in popularity due to its ability to improve application performance and support transpilation of source code in other languages into something that may get leveraged in a web browser.
Last Thursday I was lucky enough to get over to the highly regarded web development conference ffconf in Brighton. This was my first time at the event and I can say that it lived up to and even exceeded my expectations.
Every year, Esri, the world’s largest geospatial software vendor, runs its developer summit in Europe. This conference, the Esri EU DevSummit, attracts around 350 developers working with Esri technology from across Europe, all coalescing in Berlin.
All Things Open is a large, community-created open source conference in Raleigh, North Carolina, with nearly 4,000 attendees and 20 concurrent sessions.
A common complaint of modern web apps is the concept of jank; web pages being unresponsive to user input and frame rates being low. Left unmitigated, this problem leads to a poor quality experience for end users of our web applications.
Resize Observer allows developers to receive notifications when the size of an element’s content rectangle changes. This helps manage a variety of application layout scenarios including responsive application layout, flexible layouts such as split panes, or dynamic changes in content within an element in a page.
Nest is a scalable framework for building server-side applications. It is authored in TypeScript and relies on the Express framework.
At the recent TSConf, SitePen engineer Sarah Higley delivered a talk titled Escape the Office: Designing Interfaces for Other Developers. The moment you step into any large project or open source venture you must accept that code you write gets used in ways you did not originally intend.
At the recent NEJSConf, SitePen engineer Sarah Higley delivered a talk titled Don’t forget your keys. People tend to assume everyone navigates the world in the same way they do: on two legs, responding to visual cues, hearing speech, reading emotion. For developers, this often means web accessibility comes as an afterthought, if at all.
WebAssembly is an emerging standard for a low-level assembly-like language in a compact binary format that runs with near-native performance, and is available as a compilation target for a variety of languages.
Intern Recorder is a Chrome extension that can kickstart the process of creating functional tests for Intern. It was initially released in 2015 users of Intern authored test suites as AMD modules.
We have somehow reached a point in time where the integration of life in digital and physical spaces has spawned scores of scholarly articles with titles like “The emerging online life of the digital native.” In a practical sense, it has become increasingly difficult to participate in society without using the internet in some form.
It is like the old proverb, “It takes a village to raise a web framework.” As we explored in the previous post, choosing a framework goes beyond the technical features of a framework and this is certainly true when it comes to the wider community, which includes considerations like licensing, how open the framework is,
Automating browsers provide many benefits including faster execution of repetitive tasks, ability to parallelise workloads and improved test coverage for your website.
For a web framework to be effective, it should offer you more than just functionality. It doesn’t matter how much hard work you put into your application if it breaks when people use it.
Why should you care about streams? On the modern web platform, many interesting features appear which enable new functionality which were not previously possible, for example, Web Bluetooth, Background Sync & Web VR.
As we create and improve open source software, and build many applications for our customers, we’re constantly looking for things that will improve the software we create. Part of this is looking at an often dizzying array of proposed and emerging standards, and finding those that feel efficient and ready for use.
Unless you have a time machine or a TARDIS, it’s pretty rare to have solid documentation in place before an open source project is released! While we’re getting close to a beta release with the Intern 4 and while we still have a fair amount of documentation and refinements to complete, a number of people
Let’s figure out how to play our album.
As new user interface component frameworks are created and old frameworks are replaced with emerging technologies, methods for styling those components must change with them. Long gone are the days of creating a simple HTML component and importing a simple CSS file with corresponding class names.
Traditionally, engineers use mixins, decorators, inheritance, and plain code duplication to add common functionality to a handful of components. Mixins and decorators can modify the target object in such a way that you are never really sure what methods are safe to override without unwanted side effects.
Previously on Web Frameworks, we looked at how various frameworks deal with the concept of applications. Akin to listening to the whole album, we got a sense of how the frameworks pull it all together.
Applications built with web technologies, something that was a curiosity a few short years ago, have emerged onto the scene as a must have for most organizations. Transcending websites and providing users with a more open and unbounded experience, web applications are everywhere.
As businesses expand into new markets and existing markets become more diverse, it is increasingly rare that enterprise applications can expect to serve speakers of only one language, with identical expectations for how they should be addressed or be presented data.
We have previously discussed the look and feel of web frameworks. While we often become interested in a framework based on the stylishness of the widgets and applications it can create, this may lead to a similar approach to how we have historically selected music.
While instruments such as guitar and drums are part of a band, how they are used by the musicians define the style of the band’s music. Similarly, the elements of an application user interface connected together define the user experience.
Whether it is Top 40 or classical or R&B, artists and music have a recognizable look and feel.
For a concise read on why the enterprise should care about using TypeScript in its applications, look no further than Remo Jansen of the Aon Centre for Innovation and Analytics’ presentation on the 6 reasons you should be using TypeScript.
TypeScript 2.3 is the latest version in the quarterly release cycle from the TypeScript team. This release contains several useful additions to TypeScript which we have already started to leverage within some of our current projects.
dojox/gfx is Dojo 1.x’s vector graphics library, with support for SVG, Canvas, and other legacy rendering environments through a drawing API based on the semantics of SVG. This API also provides the foundation for dojox/charting. Often the biggest challenge in working with vector graphics is the large number of possible configuration settings and permutations.
In our recent post about the key features in ES2017, I was reminded just how much the standards process has changed in the past 15 years. As someone who tried to get involved early to improve standards, the process was broken and I was quickly discouraged.
As many of you know, Dojo 2 is being built on TypeScript. Many of us involved in Dojo 2 believe that TypeScript brings several advantages to developing with web technologies these days.
As we near the finalization of the proposal, it’s looking like ES8 is going to deliver much more than the simple updates of its ES7 predecessor! We wanted to take a few moments to highlight our 5 favorite things about the upcoming 2017 release.
The TypeScript team recently announced the TypeScript 2.2 release candidate which will contain key improvements to the TypeScript language.
Web applications can be deployed to many environments, including desktops, tablets, and mobile devices. We can even deploy web applications natively using a wrapper such as Apache Cordova to gain access to device features such as GPS, battery, and accelerometer data.
The motivation for Intern 4 is to make it easier to author tests with ES6+ features within tests, with or without transpilation. Want to skim? Here’s the Intern Roadmap which lists our high level status for each Intern release going forward.
Introducing Milestone Mayhem With years of building large scale web apps, we’ve experienced almost everything that goes right and wrong during software development projects.
As the new year starts to unfold, it’s time to take a quick look at the things our team at SitePen resolves to do this year.
Thanks to a generous Mozilla Open Source Support program award, Intern has expanded its testing ecosystem to include new and robust sets of tools. Engineers can now easily write tests to benchmark sections of code, test for accessibility (a11y) support, and test for visual differences.
Intern already has a wide array of capabilities and today we’re pleased to announce one more: accessibility testing.
Today we’re pleased to announce the release of Intern 3.4. This release brings usability enhancements and bugfixes, including a new benchmarking mode! We’ve outlined some of the features below, but as always, visit the release notes for more details. A number of contributors made this release possible.
This October, we delivered meetup talks on WebVR in London and Phoenix on the same day to share our early efforts in exploring WebVR with TypeScript, Dojo 2, Intern, and A-Frame.
The official name of the rebranded and relaunched merging of the jQuery Foundation and the Dojo Foundation is the JS Foundation. SitePen is excited to be a member of this new organization!
With Intern you can easily run tests using your local machine’s web browser or on any other machine running a Selenium server. Sometimes a project will need to be tested across a wide range of platforms and browsers, more than an individual user or even an enterprise may have available.
Recently on GitHub, someone accused Dojo 2 of being vapourware. This opinion came from a position of misinformation. I was glad the individual then engaged with the Dojo 2 project to understand where we are today. We are making swift progress and a beta is on the horizon.
We were recently asked about options for mixing Dojo widgets and Angular 2 components into the same application: Is it possible to render an Angular 2 component and Dojo widgets on the same page? Are there any special configuration settings needed? What’s the best way for Angular 2 and Dojo to communicate and/or send messages?
Today, we’re very happy to announce the release of Intern 3.3! This is the result of several months of work to improve Intern and its Dig Dug and Leadfoot dependencies, as well as the introduction of a new intern-cli package to make command-line testing configuration even easier.
Intern makes writing high-quality tests easier and now running the tests is even easier using intern-cli. This package provides an intern command that has a POSIX-like interface, using familiar flags and options like –help. It follows some conventions that make running Intern simpler, and provides plenty of inline help.
A quintessential British tradition is the pub quiz, a test of a group’s knowledge of obscure facts and trivia, typically shared over dinner and drinks at a pub.
In this installment of our series on building web applications, we look at the SitePen approach to solving challenges in web application development. We employ all of the solutions described in part 2 of the blog series. Additionally, we have some overarching principles we apply to our work.
While there are many challenges today with building web applications, there are also many options to address the issues we face with technology, process, and people, allowing us to reap the benefits of the web as an application platform.
Web applications provide many benefits. Most organizations seek to improve the efficiency and effectiveness of business processes through the use of software. The benefits of web applications include: Simple distribution model for end users (e.g.