Learn 11ty, Dart and Playwright

Playwright is a framework for reliable end-to-end testing of modern web apps.

playwright

Playwright provides a simple library that you can install via npm for automating various browser engines. That is what we demo in this lesson.

Playwright Library for Browser Automation

In this lesson we look at the Playwright Test concept of Fixtures. We demo the creation of various fixtures and explain the idea behind browser, context and page.

Playwright Test Fixtures, Browser Context and Page

In this lesson we demonstrate how you can create Page Objects in Playwright. The Page Object Model (lovingly called pom) is a great way to simplify your test code and make it more easy to understand and maintain in the long run.

Page Object Model Pattern with Playwright

In this lesson we look at various ways you can select different elements on page using Playwright Selectors. We also demo playwright selector engines and selector chaining

Playwright Selectors

A common post mortem debugging tool for e2e tests is screenshots and videos. These can be enabled via options in the Playwright config and that is what we demo in this lesson.

Capture Failed Test Videos and Screenshots with Playwright

Playwright provides a powerful tool in the form of the trace viewer to help you debug any issues in your test after they have failed. That is exactly what we demo in this lesson.

Postmortem Debugging Failed Tests with the Playwright Trace Viewer

In this lesson we introduce the codegen feature of Playwright which can be used to quickly generate automation / test code.

Quickly Generate Playwright Tests with Codegen

In this lesson we look at how you can use the playwright inspector to debug any issues in your tests. We run through a sample test and guide you through the various portions of the playwright inspector UI.

Debugging Playwright Tests with Inspector

GitHub fosters a fast, flexible, and collaborative development process that lets you work on your own or with others.

github

In this lesson we look at why you would need to generate snapshots on your CI server. We follow this up by creating a simple Github Action that will generate new snapshots against a pull request once you leave a specially formatted "slash command" style comment.

Generate Playwright Snapshots on your CI Server

In this lesson we look at how you can do simple VRT (visual regression testing) using Playwright tests.

Visual Regression Testing with Playwright

Visual Studio Code is an integrated development environment (IDE) built and maintained by Microsoft. It is offered free of charge.

vscode

We look at the various features of the VSCode Extension for Playwright and how it can help you with your testing workflow.

Playwright VSCode Extension

In this lesson we look at how you can add playwright to your existing web application. Along the way we also look at other neat stuff like beforeEach, describe, async web-first matchers and the hasText locator option.

Adding Playwright to your Web App

This lesson covers the basics of Playwright's testing API such as the page object, locator, locator methods and expect.

Playwright Tests API Basics

In this lesson we demo how you can quickly get setup and start using Microsoft Playwright for cross browser Web Application testing.

Setting up Microsoft Playwright

Eleventy was created to be a JavaScript alternative to Jekyll. It’s zero-config by default but has flexible configuration options. Eleventy works with your project’s existing directory structure.

Eleventy uses independent template engines. We don’t want to hold your content hostage. If you decide to use something else later, having your content decoupled in this way will make migration easier.

11ty

Our Twitch Scenes will use the static site generator Eleventy (11ty) to leverage templating features for creating the scenes. This lesson covers the base project which is available in the project repo under `/lessons/00-base`.

This lesson includes templating for the stream details and initial styling of the details section within the scene layout. The primary templating language in use is [Nunjucks](https://mozilla.github.io/nunjucks/templating.html).

Setup Eleventy Project for Creating Twitch Scenes

Flutter allows you to build beautiful native apps on iOS and Android from a single codebase.

flutter

Extension methods allow you to add new methods to classes without directly changing its original interface or creating a derived class. We will explore examples of working with this feature by extending some inbuilt types.

Learn more about Extension Methods at https://medium.com/dartlang/extension-methods-2d466cd8b308

Add New Methods to inbuilt Classes and Interfaces with Extension Methods in Dart

We will learn how to work with Lists using a variety of methods made available in the **dart:core** library. We will explore the top methods for working with List type collections.

Learn more about Lists at https://api.dartlang.org/stable/2.2.0/dart-core/List-class.html

Manipulate Lists/Arrays in Dart

We will learn how to work with Strings using a variety of methods made available in the **dart:core** library. We will explore the top methods for working with String values.

Learn more about Strings at https://api.dartlang.org/stable/2.2.0/dart-core/String-class.html

Manipulate Strings in Dart

In this lesson, we will cover Interfaces and Mixins. Interfaces act as a contract containing properties and methods that a class must define once it “implements” this interface. Mixins are Dart’s way of sharing properties and methods from multiple classes, since by design Dart adopts a single-inheritance model.

Define Interfaces and Share Class Members through Mixins in Dart

Streams represent a sequence of asynchronous events. Each event is either a data event, also called an element of the stream, or an error event, which is a notification that something has failed. When a stream has emitted all its events, a single "done" event will notify the listener that the end has been reached. In this lesson, we will learn how we can capture and handle streaming data, working with various Stream classes.

Capture and Handle Data Sequences with Streams in Dart

Pub is a package management tool that makes it easy for you to install, use, share Dart libraries, command-line tools and other assets. It comes as part of the Dart SDK, and requires a dependency file called pubspec.yaml.

Manage Package Dependencies with Pub

I've been using Cursor for a very long time and their "Agent" feature in Composer is fairly new, so I'm still getting used to it. But since Windsurf recently got onto the stage with their Cascade agent, they've slowly been gaining the mind share on the UX for coding agents. I decided to put them to the test by putting Windsurf and Cursor on the exact same screen side by side trying to accomplish the same task and to see which workflow I would prefer. I've been a diehard Cursor user for over a year now, so it's going to take a lot for me to switch to a different IDE. But I just have to say, even from this simple demo, Windsurf is looking pretty nice.

This lesson is just going to walk through creating a CLI using both tools to print out inspirational quotes and to explore how they approach the step-by-step of installing packages and running commands and setting up all the files we need to get this running.

Windsurf Cascade vs. Cursor Composer Agent Side-by-Side Comparison

This TypeScript tutorial explains how to use generics, allowing for different types to be passed as arguments. It discusses the use of shorthand syntax in generics and illustrates with examples. This method is useful for library creation, providing type safety and control to the user.

```typescript
interface PhotoMetadata<T> {
  title: string;
  takenAt: Date;
  customData: T;
}

// Function that processes a photo with custom metadata
function processPhoto<T>(photo: PhotoMetadata<T>): {
  processedTitle: string;
  daysSinceCapture: number;
  customDataSummary: T;
} {
  const today = new Date();
  const daysSinceCapture = Math.floor(
    (today.getTime() - photo.takenAt.getTime()) / (1000 * 60 * 60 * 24)
  );

  return {
    processedTitle: photo.title.toUpperCase(),
    daysSinceCapture,
    customDataSummary: photo.customData
  };
}

// Example usage with different custom data shapes
type CameraSettings = {
  iso: number;
  aperture: string;
  shutterSpeed: string;
}

type LocationData = {
  latitude: number;
  longitude: number;
  locationName: string;
}

// Using with camera settings
const photoWithCamera: PhotoMetadata<CameraSettings> = {
  title: "Sunset at beach",
  takenAt: new Date('2024-01-15'),
  customData: {
    iso: 100,
    aperture: "f/2.8",
    shutterSpeed: "1/1000"
  }
};

// Using with location data
const photoWithLocation: PhotoMetadata<LocationData> = {
  title: "Mountain vista",
  takenAt: new Date('2024-02-01'),
  customData: {
    latitude: 45.5231,
    longitude: -122.6765,
    locationName: "Mount Hood"
  }
};

const processedCameraPhoto = processPhoto(photoWithCamera);
const processedLocationPhoto = processPhoto(photoWithLocation);

processedCameraPhoto.customDataSummary.iso
processedLocationPhoto.customDataSummary.longitude

```

Basic Explanation of Typescript Generics

A very basic explanation of generic function arguments

I've been using Cursor as my primary editor for over a year now, but recently I've heard wonderful things about Windsurf AI Agent features. I decided to record myself building out something I've always wanted to make, but never made the time for.

In this lesson, I demonstrate how to leverage Windsurf's powerful agent process to create a fun word-guessing game inspired by Heads Up. Watch as I build an interactive application featuring category selection and word navigation, complete with data hosting on GitHub Gists and deployment to GitHub Pages - all in under 30 minutes (before editing the lesson down to 12 minutes)!

What makes this project particularly exciting is how Windsurf eliminates the typical friction points of development. While this game was always on my project wishlist, the overhead of setup, configuration, and deployment made it hard to justify the time investment. Windsurf's agent process handles all these pain points seamlessly, from managing URLs to orchestrating deployment.

This lesson perfectly showcases how AI agents can help developers bring their backlog of project ideas to life, transforming what would typically be time-consuming tasks into efficient, enjoyable development experiences.

Build a Word Game with Windsurf's Cascade AI Agent



Discover how to harness the power of Cursor IDE's Composer Agent feature to optimize your code. In this lesson, you'll witness an AI agent doing all the work to generate test suites, implement performance benchmarks, and create optimized function variations - all without writing a single line of code. You'll learn how to validate performance improvements through data-driven benchmarking, ensuring that optimizations are backed by concrete metrics rather than speculation. This hands-on demonstration showcases a groundbreaking approach to automated function development that combines the precision of test-driven development with the efficiency of AI-powered optimization.


Agent-Driven Development in Cursor: Testing, Benchmarking, and Optimizing Functions

This course is aimed for using `zod` effectively in projects based on TypeScript (both browser and node.js). The benefits you gain with this course is not just simply coding, but also understanding when/why/how should you perform runtime validation.

`zod` is the missing piece to TypeScript's capabilities, which can guarantee type-safety only in compile-time.

`zod` can be used whenever the compiler cannot guarantee what happens in runtime. And... it's a very frequent usecase, such as HTTP calls, websockets, etc.

In this course you get quickly up and running by:
1. using `zod` with primitives and objects
2. adapting `zod` quickly to existing projects thanks to automatic generators
3. changing the strategy frm type-first to schema-first
4. using error-throwing `parse` or non-error-throwing `safeParse` basing on your needs
5. applying `zod` to the most common usecase - validating API responses
6. handling errors the most convenient way (out of many!)

Take advantage of runtime validation with `zod`. Take advantage of the detailed lessons in this course 🔥

Effective Runtime Type Checks with Zod


Cursor can now automatically run commands in the terminal and walk step-by-step towards building out your entire project. You give it a goal, then it will suggest the commands you need to run and the files that you need to create and you can work with it to achieve what you're building. This lesson does a quick walkthough of using a Cursor Agent to build a project from scratch and guide it along the way. Cursor Agents definitely feel like a sneak peek at the future of programming!

Cursor Agents Initial Impressions - Allow an AI to Build Your Entire Project

Mock Service Worker is an API mocking library that allows you to write client-agnostic mocks and reuse them across any frameworks, tools, and environments.



Mocking WebSocket APIs with Mock Service Worker


While using anonymous functions might seem convenient, they can create difficulties when trying to identify performance bottlenecks during profiling. This lesson will demonstrate how named functions make it easier to pinpoint and address performance issues, ultimately leading to more efficient and debuggable code. Learning this practice will greatly improve your ability to locate and fix performance issues in complex projects.

Always Name Functions in JavaScript


When attempting to load the same module twice in JavaScript you'll hit a cache and code won't re-run. In scenarios where you actually do want to have state in your modules, you'll have to use a cache-busting technique by passing a query parameter to a dynamic import. This lesson walks through how to add a query parameter, how to add the appropriate types for loading dynamic modules in TypeScript, and when these techniques are valuable.

Import the Same JavaScript Module Multiple Times with Cache Busting



The include keyword in GitHub Actions empowers you to add custom variables to your matrix strategy, providing flexibility beyond standard configurations. In this video, we'll explore how include allows you to define specific combinations of variables, enhancing control over your workflow runs. You'll see how this feature enables you to tailor jobs for unique environments or scenarios not covered by the default matrix options. By leveraging include, you can efficiently manage complex build processes with greater precision. This technique helps you streamline your CI/CD pipeline, making it more adaptable to your project's evolving needs.

Search

Search Results