Learn Aria, Chai and Remix

Remix is a full stack web framework that focuses on web standards and the server/client model so that you can develop the features your users want and need without being bogged down in over-abstractions. When you get good with Remix, you actually get good at the foundations of web development.

remix

Mocking authentication comes down to how it's implemented. With Mock Service Worker, you can mock the "Set-Cookie" response header to emulate a user session, but with Remix you don't even have to. Instead, in this lesson we will intercept only the authorization call to a database, leaving Remix to handle sessions, cookies, and auth state for us. 

Use MSW to Mock Authentication in Remix

WAI-ARIA, the Accessible Rich Internet Applications Suite, defines a way to make Web content and Web applications more accessible to people with disabilities. It especially helps with dynamic content and advanced user interface controls developed with Ajax, HTML, JavaScript, and related technologies. 

aria

We'll go over the work it takes to use ARIA to show why Semantic HTML is almost always the safer bet. 

Create a Semantic Checkbox vs an ARIA Checkbox

Debug Computed Accessibility Properties with Chrome Dev Tools

In this lesson, we use the element inspector in Chrome to test and improve our contrast to meet WCAG AA Contrast Ratio Standards.

Resources:
- [WebAIM - Contrast and Color Accessibility](https://webaim.org/articles/contrast/)

Debugging Accessible Contrast with Chrome Dev Tools

In this lesson, we are creating the audio player interface more visually appealing using icons from the React Icons library and Font Awesome, in this process, we are also ensuring that the interface remains accessible to screen readers by providing text descriptions for the icons, first by using the `title` prop on each icon, and then by implementing a `visually hidden` technique that hides the text descriptions from sighted users but makes them available to screen readers. This involves copying and pasting some CSS code to create a visually-hidden class, adding an `aria-hidden` attribute to each icon, wrapping each icon in a React fragment, and then adding a `span` element above each icon with the corresponding text description and the `visually-hidden` class.

**Think about:**  
- Why use `aria-hidden` or visually hide spans? 
- What value does this add to screen reader users?

Design Accessible Buttons Using Icons

In this lesson, we will create event listeners for the play and pause events on an audio player element and use these listeners to update the value of a variable called `isPlaying` that tracks the current state of the player (e.g., whether it is currently playing or paused). The event listeners, named `onPlay` and `onPause`, will be triggered when the user presses the play or pause button on the audio player element itself, not on a custom play button that may have been created.

Add Play and Pause Events to the Audio Player

We are creating an input of type range with an associated label, this input is to represent the current playback position in the audio, and the user will be able to change the playback position using the input.

The input value is set to be the media time state, it is added a minimum value of 0 and a maximum value as the duration. The demonstration shows how the media time state updates accordingly when the user changes the time using the input range.

A function called `onScrubberChange` is added, which takes in an event as an argument and `console.logs` the value of that event. The `onChange` event is added to the input, ensuring it works as expected. A variable sets the media time state and the current time on the audio ref.

**Think about:** Why do we use the `event.target.value` to set the new `mediaTime` (reminder that the value of the range is bound to `mediaTime`....maybe take a look at that with the formatter)

Create the Audio Scrubber to Control Playback Position

In this lesson, we are creating a new state called `mediaTime` with an initial value of 0, updating sample text in the markup to display the value of `mediaTime`, and adding an event listener to the audio element for the `timeUpdate` event.

In the `timeUpdate` event listener callback function, the `mediaTime` state is set to the audio element's current time, which can be accessed using the `audioRef.current.currentTime`. A function is added to the `onTimeUpdate` event of the audio element, to be able to track the current time. And a time formatter is added to format the time for displaying elapsed time and total time.

**Think about:** How often does onTimeUpdate update? (every second, not every millisecond) 

Tracking Audio Playback Progress by Adding Elapsed Time 

We created a duration state with an initial value of zero, then added an event listener to the audio element for the `loadedMetaData` event. In the event listener callback function, you set the duration state's value to be the audio element's current duration. This ensures that the value of the duration state is only set once the audio element metadata is loaded, allowing you to display the accurate total time of the audio file.

**Think about:** Why do we need to set the duration on the `onLoadedMetadata` event?

"The `onLoadedMetadata` event occurs when metadata for the specified audio/video has been loaded." You can read the docs [here](https://www.w3schools.com/tags/av_event_loadedmetadata.asp) 


 Implementing a Duration State 

Using a GitHub repo to deploy our application to Vercel, keeps our code and live production site in sync. In this lesson we look at using the [GitHub CLI](https://cli.github.com/) tool to create a public repo, and adding it as a remote origin for our project.

Additionally, we create a new Vercel project from this GitHub repo, add our Supabase environment variables, and deploy. Lastly, we update the Homepage URL in our GitHub OAuth app to be our new Vercel URL, and set our Supabase project's [Authentication Site URL](https://app.supabase.com/project/_/auth/url-configuration) to our new live application URL.

## Extension ideas

- Style the app using Tailwind CSS (or another method of choice)
- Implement the ability for a user to `update` and `delete` their own messages
- Add the option to set a username and display this alongside messages
- Add separate message threads/chat rooms
- Implement private messages/chat rooms

## Resources

- [GitHub CLI](https://cli.github.com/)
- [Vercel docs](https://vercel.com/docs)
- [Deploying Remix app to Vercel](https://vercel.com/guides/deploying-remix-with-vercel)

Deploy a Remix Application to Vercel from a GitHub Repository

To mutate data in Remix, we use an Action function. In this lesson, we look at creating a Remix `<Form />` to submit the content of a message as a `post` request to our `Action` function.

Additionally, we use the server-side Supabase client from the Remix Auth Helpers package to make an authenticated request to Supabase, writing the new message to the `messages` table.

Futhermore, we run into an issue with RLS as we have not yet written a policy for the `insert` action. By setting this to the `authenticated` role and ensuring that the `user_id` column is equal to the value returned by the `auth.uid()` function - a function we get from Supabase to retrieve the ID for the user attempting to insert a new row - we ensure that users can not write a message on someone else's behalf.

Lastly, we use the `auth.uid()` function to set the default value of the `user_id` column to the ID of the user attempting to `insert` the new row in the `messages` table.

## Code Snippets

**Write data to Supabase**

```tsx
export const action = async ({ request }: ActionArgs) => {
  const response = new Response();
  const supabase = createServerSupabase({ request, response });

  const { message } = Object.fromEntries(await request.formData());

  await supabase.from("messages").insert({ content: String(message) });

  return json(null, { headers: response.headers });
};
```

**Form to submit to action**

```tsx
<Form method="post">
  <input type="text" name="message" />
  <button type="submit">Send</button>
</Form>
```

**Add policy for insert**

```sql
create policy "users can insert their own messages" on "public"."messages"
as permissive for insert
to authenticated
wuth check (user_id = auth.uid());
```

> SQL code snippets can be run against your Supabase database by heading over to your project's [SQL Editor](https://app.supabase.com/project/_/sql), pasting them into a new query, and clicking `RUN`.

## Resources

- [Supabase docs - insert](https://supabase.com/docs/reference/javascript/insert)
- [Implement Row Level Security in Supabase (video)](https://www.youtube.com/watch?v=Ow_Uzedfohk)
- [Remix docs - Writing data](https://remix.run/docs/en/v1/guides/data-writes)

Securely Mutate Supabase Data with Remix Actions

The OAuth flow is asynchronous. This means we get redirected to the landing page before GitHub and Supabase have decided that you can be trusted! 👍

Since our Loader functions get called when we first load the page they make a request to Supabase before receiving a valid access token. This causes RLS to deny the request to select data.

Once our session has been correctly set, Supabase is happy but we aren't telling Remix to fetch this data again. In this lesson, we look at combining the `onAuthStateChange` hook from Supabase with the `useRevalidator` hook in Remix to recall any active `loaders` when the state of our user changes, keeping data in sync with mutations.

Therefore, any time the user's session is updated - the auth flow has completed for either signing in or out - Remix will automatically call all loader functions that are active on the current route (this could be many with nested routing), fetching fresh data from Supabase with a valid access token.

## Code Snippets

**onAuthStateChange listener**

```tsx
useEffect(() => {
  const {
    data: { subscription },
  } = supabase.auth.onAuthStateChange((event, session) => {
    if (session?.access_token !== serverAccessToken) {
      revalidator.revalidate()
    }
  });

  return () => {
    subscription.unsubscribe();
  };
}, [supabase, serverAccessToken, revalidator]);
```

## Resources

- [Supabase docs - onAuthStateChange](https://supabase.com/docs/reference/javascript/auth-onauthstatechange)
- [Reactor Router docs - useRevalidator](https://reactrouter.com/en/main/hooks/use-revalidator)

Keep Data in Sync with Mutations Using Active Remix Loader Functions

Remix Loaders allow us to fetch data server-side, before rendering a component. This works great if you are implementing your authorization rules for data fetching in the loader function, however, Supabase allows us to use Row Level Security policies to write access policies alongside the data in the database.

By default, `supabase-js` stores session data in `localStorage`, which exists only within the user's browser. If we want this session to be available within Loader or Action functions in Remix, we need to store the session in a cookie. Cookies are automatically sent with every request to the server.

In this lesson, we look at using the Supabase Auth Helpers package for Remix to automate this process, and swap out the storage mechanism for the Supabase client, to use cookies to store session data.

Additionally, we refactor our application to use the new `createServerClient` and `createBrowserClient` functions, making cookies the single source of truth about the user's current session, across the server and client-side of our Remix app.

## Code Snippets

**Install Remix Auth Helpers**

```bash
npm i @supabase/auth-helpers-remix
```

**Create server-side Supabase client**

```tsx
import { createServerClient } from "@supabase/auth-helpers-remix";

import type { Database } from "db_types";

export default ({
  request,
  response,
}: {
  request: Request;
  response: Response;
}) =>
  createServerClient<Database>(
    process.env.SUPABASE_URL!,
    process.env.SUPABASE_ANON_KEY!,
    { request, response }
  );
```

**Create client-side Supabase client (simplified)**

```tsx
import { useState } from "react";
import { createBrowserClient } from "@supabase/auth-helpers-remix";

export const loader = async ({ request }: LoaderArgs) => {
  const env = {
    SUPABASE_URL: process.env.SUPABASE_URL!,
    SUPABASE_ANON_KEY: process.env.SUPABASE_ANON_KEY!,
  };

  return json({ env });
};

const { env, session } = useLoaderData<typeof loader>();

const [supabase] = useState(() =>
  createBrowserClient<Database>(env.SUPABASE_URL, env.SUPABASE_ANON_KEY)
);

return <Outlet context={{ supabase }} />;
```

**Use Supabase in a loader**

```tsx
export const loader = async ({ request }: LoaderArgs) => {
  const response = new Response();
  const supabase = createServerSupabase({ request, response });

  const { data } = await supabase.from("messages").select();

  return json({ data }, { headers: response.headers });
};
```

**Use Supabase in an action**

```tsx
export const action = async ({ request }: ActionArgs) => {
  const response = new Response();
  const supabase = createServerSupabase({ request, response });

  const { data } = await supabase.from("messages").insert({ content: "hello" });

  return json({ data }, { headers: response.headers });
};
```

**Use Supabase in a component**

```tsx
import { useOutletContext } from "@remix-run/react";

import type { SupabaseOutletContext } from "~/root";

export default function Login() {
  const { supabase } = useOutletContext<SupabaseOutletContext>();

  const handleLogin = async () => {
    await supabase.auth.signInWithOAuth({
      provider: "github",
    });
  };

  return <button onClick={handleLogin}>Login</button>;
}
```

## Resources

- [Supabase docs - Remix Auth Helpers](https://supabase.com/docs/guides/auth/auth-helpers/remix)

Make Cookies the User Session Single Source of Truth with Supabase Auth Helpers

The [supabase-js](https://supabase.com/docs/reference/javascript) package allows us to connect to our Supabase project, and easily query and mutate data. In this lesson, we install `supabase-js`, set up environment variables for `SUPABASE_URL` and `SUPABASE_ANON_KEY`, and create a Supabase client to use across our application.

Additionally, we look at writing an RLS policy to enable `read` access to our `messages` table, use our Supabase client to select all messages, and display them in our Remix app on load.

## Code Snippets

**Install supabase-js**

```bash
npm i @supabase/supabase-js
```

**Use a Loader function to fetch data**

```tsx
export const loader = async () => {
  return null;
};
```

**Fetch data with Supabase Client**

```tsx
const { data } = await supabase.from("messages").select();
```

**Full component**

```tsx
import { useLoaderData } from "@remix-run/react";
import supabase from "utils/supabase";

export const loader = async ({}) => {
  const { data } = await supabase.from("messages").select();
  return { data };
};

export default function Index() {
  const { data } = useLoaderData();
  return <pre>{JSON.stringify(data, null, 2)}</pre>;
}
```

**Enable read access with RLS policy**

```sql
create policy "users can read messages" ON "public"."messages"
as permissive for select
to public
using (true);
```

> SQL code snippets can be run against your Supabase database by heading over to your project's [SQL Editor](https://app.supabase.com/project/_/sql), pasting them into a new query, and clicking `RUN`.

## Resources

- [Supabase-js docs](https://supabase.com/docs/reference/javascript)
- [Implement Row Level Security in Supabase (video)](https://www.youtube.com/watch?v=Ow_Uzedfohk)
- [Auto-generated project docs](https://app.supabase.com/project/_/api)

Query Supabase Data with Remix Loaders

[Remix](https://remix.run) is a web application framework built on top of React, that gives you sprinkles of server when you need it - fetching data on page load, mutating values in a db etc. In this lesson, we use the `create-remix` package to setup our new app. Additionally, we run the project is development mode with `npm run dev` and update the content on our `index` route.

## Code Snippets

**Create a Remix app**

```bash
npx create-remix <name-of-project>
```

## Resources

- [Remix docs](https://remix.run/docs/en/v1)

Setting Up a Remix Project

[Supabase](http://supabase.com?utm_source=egghead&utm_campaign=remix) is a collection of open-source tools that wrap around a PostgreSQL database. In this course, we look at building a realtime chat application with Remix, using Supabase for db hosting, authentication, authorization and subscribe to realtime db events - updating the UI as the database changes.

We will learn about:

- loaders and actions in Remix
- querying and mutating data with Supabase
- authentication with GitHub
- authorization with RLS
- merging client and server state with realtime events
- deploying a Remix app to Vercel

This course is 100% TypeScript, however, don't stress if you don't have any experience with TS, as Supabase does most of the heavy lifting here! 🎉

TypeScript is a typed superset of JavaScript that compiles to plain JavaScript.

typescript

Build a Realtime Chat App with Remix and Supabase

In your pnpm monorepo, you can easily create new applications under your apps folder. 

Here, you'll create a new Remix app by running the command `pnpx create-remix@latest`. The app you generate functions just like any other full featured Remix app!

Add a Remix App to a pnpm Workspace Monorepo

Learn Remix by Building a Social Media Platform with TypeScript and Prisma

In lesson 08, [Deploy a Remix Application](https://egghead.io/lessons/egghead-deploy-a-remix-application-with-production-database-to-the-internet-through-vercel), we said that the app was MVP status. This isn’t quite true for many applications. You will inevitably need users on your site to make it useful for your customers (or even for yourself).

To get started adding users, you will update Prisma with a user model and associate it to Posts. From there you’ll update your posts to display user information. You’ll see how to migrate a Prisma schema in PlanetScale as you deploy these changes.

One nice tid bit you will pick up along the way is a TypeScript 4.5 feature, Awaited. Awaited will unwrap a promise type for you so that you don’t have to do it yourself which is a big relief.

Create and Utilize a User Model with Prisma in Remix

Finally, you want to associate users to the posts that they make. To do this you will grab the user data from authenticator.isAuthenticated API to pass to the post creation. This data does not need to be validated because it’s coming from the session storage which has already been validated.

Add User Data to a Post Creation in Remix

Currently the only way to know if you are logged in is if you check the cookie that is set in the browser. This isn’t super user friendly. You want to add a visual cue as well as a log out button to the nav.   To accomplish this, you can check if a user exists with the isAuthenticated function that was created in the auth service. If there is a user you will display their email, loaded up from the isAuthenticated check, as well as a log out button.

The log out button will post to a resource route. This route will log out the user and redirect them to the log in page. 

Finally, you will lock up the index page so only logged in users can see and add posts.

Implement Log out Functionality and Only Allow Logged in Users to See Posts

In this lesson, you'll discover how to style View Transitions using CSS pseudo-selectors to create custom animation effects. We'll transform the default cross-fade into a smooth slide transition by targeting the ::view-transition-old and ::view-transition-new pseudo-elements. You'll learn how these powerful selectors give you precise control over your transition animations, allowing you to create more engaging and personalized user experiences with just a few lines of CSS.

Customize View Transitions with CSS Using view-transition-old and view-transition-new

In this lesson, you'll learn how to implement smooth state transitions in your web applications using the browser's built-in View Transitions API. We'll create a simple example that demonstrates how to animate between different text states with just a few lines of code - no external libraries required. This powerful native API makes it easy to add professional-looking transitions to your user interface, enhancing the user experience with minimal effort.

Create Smooth UI Transitions with the Native View Transitions API

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.

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