Javascript

Choosing Remix: The JavaScript Fullstack Framework and Building Your First Application

Published Sep 16, 2022

Updated Feb 13, 2023

6 min read

This article was written over 18 months ago and may contain information that is out of date. Some content may be relevant but please refer to the relevant official documentation or available resources for the latest information.

Remix is a React framework for building server-side rendering full-stack applications. It focuses on using web standards to build modern user interfaces. Remix was created by the team behind React Router, and was recently open-sourced for the community.

Remix extends most of the core functionality of React and React Router with server-side rendering, server requests, and backend optimization.

But why start using Remix? Remix comes with a number of advantages:

Nested routes - nested routes help eliminate nearly every loading state by using React Router’s outlet to render nested routes from directories and subdirectories.
Setup is easy! Spinning up a remix project takes just a few minutes and gets you productive immediately.
Remix uses server side progressive enhancement which means only necessary JavaScript, JSON, and CSS content is sent to the browser.
Remix focuses on server-side rendering.
File-system-based routing automatically generates the router configuration based on your file directory.
Remix is built on React which makes it easy to use if you know React.

Key Features

Let’s highlight a few key features of Remix you should be aware of.

Nested Route

Routes in Remix are file-system-based. Any component in the route directory is handled as a route and rendered to its parent outlet components.

If you define a parent component inside the routes directory, and then different routes inside a directory with the same name as the parent component, the latter will be nested within the first one.

Error boundaries

Error handling with applications is critical. In many cases, a single error can cause the entire application to be affected.

With Remix, when you get an error in a Remix component or a nested route, the errors are limited to the component and the component will fail to render or it will display the error without disrupting the entire application’s functionality.

Loading State

Remix handles loading states in parallel on the server and sends the fully formed HTML document to the browser; this eliminates the need to use a loading skeleton or spinner when fetching data or submitting form data.

Loaders and Actions

Among the most exciting features of Remix are Loaders and Actions.

These are special functions:

Loaders are functions (Hooks) that retrieve dynamic data from the database or API using the native fetch API. You can add loaders to a component by calling the useLoaderData() hook.

Actions are functions used to mutate data. Actions are mostly used to send form data to the API or database, to make changes to an API, or perform a delete action.

Building Your First Remix App

The next portion of this blog post will show you how to build your first Remix app!

We will be building a small blog app with primsa’s SQLite to store the posts.

To start a Remix project the prerequisites are:

A familiarity with JavaScript and React
Node.js installed
A code editor i.e VSCode

Open your system terminal and run:

npx create-remix@latest

You can accept the default prompts or use your own preferences.

Remix will install all the dependencies it requires and scaffold the application with directories and files.

In the project’s directory let install the other dependencies we will be using, run:

npm install bootstrap

You should use something like the directory in the image.

File structure walk through

The app directory contains the main building files for our Remix application.

The route directory holds all the routes that expose the exported default function as the route handler from the file.

entry.client.jsx and entry.server.jsx are core Remix’s files. Remix uses entry.client.jsx as the entry point for the browser bundle, and uses entry.server.jsx to generate the HTTP response when rendering on the server.

root.jsx is the root component of Remix application, the default export is the layout component that renders the rest of the app in an <Outlet />

These are the files we really want to touch on in our project. To learn more about the file directory, check out Remix’s API conventions.

Project set up

Open the root.jsx file and replace the code with:

import { Links, LiveReload, Meta, Outlet } from "@remix-run/react";
import bootstrapCSS from "bootstrap/dist/css/bootstrap.min.css";

export const links = () => [{ rel: "stylesheet", href: bootstrapCSS }];

export const meta = () => ({
  charset: "utf-8",
  viewport: "width=device-width,initial-scale=1",
});

export default function App() {
  return (
    <Document>
      <Layout>
        <Outlet />
      </Layout>
    </Document>
  );
}

function Layout({ children }) {
  return (
    <>
      <nav className="navbar navbar-expand-lg navbar-light bg-light px-5 py-3">
        <a href="/" className="navbar-brand">
          Remix
        </a>
        <ul className="navbar-nav mr-auto">
          <li className="nav-item">
            <a className="nav-link" href="/posts">Posts </a>
          </li>
        </ul>
      </nav>

      <div className="container">{children}</div>
    </>
  );
}

function Document({ children }) {
  return (
    <html>
      <head>
        <Links />
        <Meta />
        <title>ThisDot Labs Code Blog</title>
      </head>
      <body>
        {children}
        {process.env.NODE_ENV === "development" ? <LiveReload /> : null}
      </body>
    </html>
  );
}

Since we are using bootstrap for styling we imported the minified library, Remix uses the <link rel="stylesheet"> to add stylesheet at component level using the Route Module links export.

The links function defines which elements to add to the page when the user visits the route. Visit Remix Styles to learn more about stylesheets in Remix.

Similar to the stylesheet, Remix can add the Meta tags to the route header by calling Meta Module. The meta function defines which meta elements you can add to the routes. This is a huge plus for your application’s SEO.

The app file has three components with a default export of the App component. Here, we declared a Document Component for the HTML document template, a Layout Component to further improve the template layout for rendering components, and added the {process.env.NODE_ENV === "development" ? <LiveReload /> : null} for Hot reload when changing things in the file during development.

One important note is to not confuse Links with Link. The latter, Link, is a router component for matching routes in Remix’s apps. We will handle the components to match our routes below.

To test out the application:

npm run dev

You should have a similar app as shown below:

Let’s configure the db we will use for the app. We will use primsa SQLite to store the posts.

Install the Prisma packages in your project:

npm install prisma @prisma-client

Now let’s initialize the prisma SQlite in project:

npx prisma init --datasource-provider sqlite

This will add a Prisma directory to the project.

Open prisma/schema.prisma and add the following code at the end of the file:

model Post {
  slug     String @id
  title    String
  body String

  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt
}

This is the schema for the blog database.

Simply, the schema is identifying that we will need a slug which will be a unique string and used for our blog’s unique route. The title property is also a string type for the title of our blog. The body type of string will hold the body, and finally we want to have the dates created and updated.

Now, let’s push the schema to Prisma:

npx prisma db push

Prisma will create a dev.db in the Prisma directory.

Now let's seed our database with a couple posts. Create prisma/seed.js and add this to the file.

const {PrismaClient} = require('@prisma/client')

const prisma = new PrismaClient()

async function seed() {

  await Promise.all(
    getPosts().map(post => {

      return prisma.post.create({data: post})
    })
  )
}

seed()

function getPosts() {
  return [
    {
      title: 'JavaScript Performance Tips',
      slug: "javaScript-performance-tips",
      body: `We will look at 10 simple tips and tricks to increase the speed of your code when writing JS`,
    },
    {
      title: 'Tailwind vs. Bootstrap',
      slug: `tailwind-vs-bootstrap`,
      body: `Both Tailwind and Bootstrap are very popular CSS frameworks. In this article, we will compare them`,
    },
    {
      title: 'Writing Great Unit Tests',
      slug: `writing-great-unit-tests`,
      body: `We will look at 10 simple tips and tricks on writing unit tests in JavaScript`,
    },
    {
      title: 'What Is New In PHP 8?',
      slug: `what-is-new-in-PHP-8`,
      body: `In this article we will look at some of the new features offered in version 8 of PHP`,
    },
  ]
}

Now edit the package.json file just before the script property and add this:

  "prisma": {
    "seed": "node prisma/seed"
  },
  "scripts": {
…

Now, to seed the db with Prisma, run:

npx prisma db seed

Our database setup is now done.

There is just one more thing for database connection, We need to create a typescript file app/utils/db.server.ts.

We specify a server file by appending .server at the end of the file name, Remix will compile and deploy this file on the server..

Add the code below to the file:

import { PrismaClient } from "@prisma/client";

let db: PrismaClient

declare global {
  var __db: PrismaClient | undefined
}

if (process.env.NODE_ENV === 'production') {
  db = new PrismaClient()
  db.$connect()
} else {
  if (!global.__db) {
    global.__db = new PrismaClient()
    global.__db.$connect()
  }

  db = global.__db
}

export { db }

Now, go back to the code editor and create post.jsx in the route directory, and add the following code:

import { Outlet } from "@remix-run/react"

function Posts() {
  return (
    <>
      <Outlet />
    </>
  )
}

export default Posts

All we are doing is rendering our nested routes of posts here, nothing crazy.

Now create routes/posts/index.jsx

import { Link, useLoaderData } from "@remix-run/react";
import {db} from '../../utils/db.server';

export const loader = async () => {
  const data = {
    posts: await db.post.findMany({
      take: 20,
      select: {slug: true, title: true, createdAt: true},
      orderBy: {createdAt: 'desc'}
    })
  }
  return data
}

function PostItems() {
  const {posts} = useLoaderData()
  return (
    <>
      <div>
        <h1>Posts</h1>
        <Link to='/posts/new' className="btn btn-primary">New Post</Link>
      </div>
      <div className="row mt-3">
      {posts.map(post => (
        <div className="card mb-3 p-3" key={post.id}>
          <Link to={`./${post.slug}`}>
            <h3 className="card-header">{post.title}</h3>
            {new Date(post.createdAt).toLocaleString()}
          </Link>
        </div>
      ))}

      </div>
    </>
  )
}

export default PostItems

Here, we are declaring the loader and fetching all the posts from the database with a limit of 20 and destructuring the posts from the useLoaderData hook, then finally looping through the returned posts.

Dynamic Routes

Remix dynamic routes are defined with a $ sign and the id key. We will want to use the slugs properties as our dynamic routes for the blogs.

To do this, create app/routes/posts/$postSlug.jsx

import {Link, useLoaderData} from "@remix-run/react";
import {db} from '../../utils/db.server';

export const loader = async ({params}) => {
  const post = await db.post.findUnique({
    where: {slug: params.postSlug}
  })

  if (!post) throw new Error('Post not found')

  const data = {post}

  return data
}

function Post() {
  const {post} = useLoaderData() 
  return (
    <div className="card w-100">
      <div className="card-header">
        <h1>{post.title}</h1>
      </div>
      <div className="card-body">{post.body}</div>
      <div className="card-footer">
        <Link to='/posts' className="btn btn-danger">Back</Link>
      </div>
    </div>
  )
}

export default Post

Here, the loader is fetching from the database using the unique slug we provided and rendering the article.

To add where to post new blogs, create app/routes/posts/new.jsx, and the following code:

import { redirect } from "@remix-run/node";
import { Link } from "@remix-run/react";
import { db } from "../../utils/db.server";

export const action = async ({ request }) => {
  const form = await request.formData();

  const title = form.get("title");
  const body = form.get("body");
  const fields = { title, body, slug: title.split(‘ ‘).join(‘-’) };

  const post = await db.post.create({ data: fields });

  return redirect(`/posts/${post.slug}`);
};

function NewPost() {
  return (
    <div className="card w-100">
<form method="POST">
      <div className="card-header">
        <h1>New Post</h1>
        <Link to="/posts" className="btn btn-danger">
          Back
        </Link>
      </div>

      <div className="card-body">

          <div className="form-control my-2">
            <label htmlFor="title">Title</label>
            <input type="text" name="title" id="title" />
          </div>
          <div className="form-control my-2">
            <label htmlFor="body">Post Body</label>
            <textarea name="body" id="body" />
          </div>

      </div>
      <div className="card-footer">
        <button type="submit" className="btn btn-success">
          Add Post
        </button>
      </div>
        </form>
    </div>
  );
}

export default NewPost;

We created an action function to handle the form post request, and Remix will catch all the formData by passing the request.

And there you have it! You’ve created a functional blog application.

Conclusion

In this article, we learned why Remix is a great choice for building your next application, and why it’s becoming a more popular framework to use amongst developers.

We also explored the core features of Remix and learned how to build a sample blog application using a database.

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.

About the author(s)

Hassan Sani
@inidaname @inidaname

Exploring Angular Forms: A New Alternative with Signals

Exploring Angular Forms: A New Alternative with Signals In the world of Angular, forms are essential for user interaction, whether you're crafting a simple login page or a more complex user profile interface. Angular traditionally offers two primary approaches: template-driven forms and reactive forms. In my previous series on Angular Reactive Forms, I explored how to harness reactive forms' power to manage complex logic, create dynamic forms, and build custom form controls. A new tool for managing reactivity - signals - has been introduced in version 16 of Angular and has been the focus of Angular maintainers ever since, becoming stable with version 17. Signals allow you to handle state changes declaratively, offering an exciting alternative that combines the simplicity of template-driven forms with the robust reactivity of reactive forms. This article will examine how signals can add reactivity to both simple and complex forms in Angular. Recap: Angular Forms Approaches Before diving into the topic of enhancing template-driven forms with signals, let’s quickly recap Angular's traditional forms approaches: 1. Template-Driven Forms: Defined directly in the HTML template using directives like ngModel, these forms are easy to set up and are ideal for simple forms. However, they may not provide the fine-grained control required for more complex scenarios. Here's a minimal example of a template-driven form: ` ` 2. Reactive Forms: Managed programmatically in the component class using Angular's FormGroup, FormControl, and FormArray classes; reactive forms offer granular control over form state and validation. This approach is well-suited for complex forms, as my previous articles on Angular Reactive Forms discussed. And here's a minimal example of a reactive form: ` ` Introducing Signals as a New Way to Handle Form Reactivity With the release of Angular 16, signals have emerged as a new way to manage reactivity. Signals provide a declarative approach to state management, making your code more predictable and easier to understand. When applied to forms, signals can enhance the simplicity of template-driven forms while offering the reactivity and control typically associated with reactive forms. Let’s explore how signals can be used in both simple and complex form scenarios. Example 1: A Simple Template-Driven Form with Signals Consider a basic login form. Typically, this would be implemented using template-driven forms like this: ` ` This approach works well for simple forms, but by introducing signals, we can keep the simplicity while adding reactive capabilities: ` ` In this example, the form fields are defined as signals, allowing for reactive updates whenever the form state changes. The formValue signal provides a computed value that reflects the current state of the form. This approach offers a more declarative way to manage form state and reactivity, combining the simplicity of template-driven forms with the power of signals. You may be tempted to define the form directly as an object inside a signal. While such an approach may seem more concise, typing into the individual fields does not dispatch reactivity updates, which is usually a deal breaker. Here’s an example StackBlitz with a component suffering from such an issue: Therefore, if you'd like to react to changes in the form fields, it's better to define each field as a separate signal. By defining each form field as a separate signal, you ensure that changes to individual fields trigger reactivity updates correctly. Example 2: A Complex Form with Signals You may see little benefit in using signals for simple forms like the login form above, but they truly shine when handling more complex forms. Let's explore a more intricate scenario - a user profile form that includes fields like firstName, lastName, email, phoneNumbers, and address. The phoneNumbers field is dynamic, allowing users to add or remove phone numbers as needed. Here's how this form might be defined using signals: ` > Notice that the phoneNumbers field is defined as a signal of an array of signals. This structure allows us to track changes to individual phone numbers and update the form state reactively. The addPhoneNumber and removePhoneNumber methods update the phoneNumbers signal array, triggering reactivity updates in the form. ` > In the template, we use the phoneNumbers signal array to dynamically render the phone number input fields. The addPhoneNumber and removePhoneNumber methods allow users to reactively add or remove phone numbers, updating the form state. Notice the usage of the track function, which is necessary to ensure that the ngFor directive tracks changes to the phoneNumbers array correctly. Here's a StackBlitz demo of the complex form example for you to play around with: Validating Forms with Signals Validation is critical to any form, ensuring that user input meets the required criteria before submission. With signals, validation can be handled in a reactive and declarative manner. In the complex form example above, we've implemented a computed signal called formValid, which checks whether all fields meet specific validation criteria. The validation logic can easily be customized to accommodate different rules, such as checking for valid email formats or ensuring that all required fields are filled out. Using signals for validation allows you to create more maintainable and testable code, as the validation rules are clearly defined and react automatically to changes in form fields. It can even be abstracted into a separate utility to make it reusable across different forms. In the complex form example, the formValid signal ensures that all required fields are filled and validates the email and phone numbers format. This approach to validation is a bit simple and needs to be better connected to the actual form fields. While it will work for many use cases, in some cases, you might want to wait until explicit "signal forms" support is added to Angular. Tim Deschryver started implementing some abstractions around signal forms, including validation and wrote an article about it. Let's see if something like this will be added to Angular in the future. Why Use Signals in Angular Forms? The adoption of signals in Angular provides a powerful new way to manage form state and reactivity. Signals offer a flexible, declarative approach that can simplify complex form handling by combining the strengths of template-driven forms and reactive forms. Here are some key benefits of using signals in Angular forms: 1. Declarative State Management: Signals allow you to define form fields and computed values declaratively, making your code more predictable and easier to understand. 2. Reactivity: Signals provide reactive updates to form fields, ensuring that changes to the form state trigger reactivity updates automatically. 3. Granular Control: Signals allow you to define form fields at a granular level, enabling fine-grained control over form state and validation. 4. Dynamic Forms: Signals can be used to create dynamic forms with fields that can be added or removed dynamically, providing a flexible way to handle complex form scenarios. 5. Simplicity: Signals can offer a simpler, more concise way to manage form states than traditional reactive forms, making building and maintaining complex forms easier. Conclusion In my previous articles, we explored the powerful features of Angular reactive forms, from dynamic form construction to custom form controls. With the introduction of signals, Angular developers have a new tool that merges the simplicity of template-driven forms with the reactivity of reactive forms. While many use cases warrant Reactive Forms, signals provide a fresh, powerful alternative for managing form state in Angular applications requiring a more straightforward, declarative approach. As Angular continues to evolve, experimenting with these new features will help you build more maintainable, performant applications. Happy coding!...

Oct 4, 2024

5 mins

AngularJavaScript

How to build an AI assistant with OpenAI, Vercel AI SDK, and Ollama with Next.js

In today’s blog post, we’ll build an AI Assistant using three different AI models: Whisper and TTS from OpenAI and Llama 3.1 from Meta. While exploring AI, I wanted to try different things and create an AI assistant that works by voice. This curiosity led me to combine OpenAI’s Whisper and TTS models with Meta’s Llama 3.1 to build a voice-activated assistant. Here’s how these models will work together: * First, we’ll send our audio to the Whisper model, which will convert it from speech to text. * Next, we’ll pass that text to the Llama 3.1 model. Llama will understand the text and generate a response. * Finally, we’ll take Llama’s response and send it to the TTS model, turning the text back into speech. We’ll then stream that audio back to the client. Let’s dive in and start building this excellent AI Assistant! Getting started We will use different tools to build our assistant. To build our client side, we will use Next.js. However, you could choose whichever framework you prefer. To use our OpenAI models, we will use their TypeScript / JavaScript SDK. To use this API, we require the following environmental variable: OPENAI_API_KEY— To get this key, we need to log in to the OpenAI dashboard and find the API keys section. Here, we can generate a new key. Awesome. Now, to use our Llama 3.1 model, we will use Ollama and the Vercel AI SDK, utilizing a provider called ollama-ai-provider. Ollama will allow us to download our preferred model (we could even use a different one, like Phi) and run it locally. The Vercel SDK will facilitate its use in our Next.js project. To use Ollama, we just need to download it and choose our preferred model. For this blog post, we are going to select Llama 3.1. After installing Ollama, we can verify if it is working by opening our terminal and writing the following command: Notice that I wrote “llama3.1” because that’s my chosen model, but you should use the one you downloaded. Kicking things off It's time to kick things off by setting up our Next.js app. Let's start with this command: ` After running the command, you’ll see a few prompts to set the app's details. Let's go step by step: * Name your app. * Enable app router. The other steps are optional and entirely up to you. In my case, I also chose to use TypeScript and Tailwind CSS. Now that’s done, let’s go into our project and install the dependencies that we need to run our models: ` Building our client logic Now, our goal is to record our voice, send it to the backend, and then receive a voice response from it. To record our audio, we need to use client-side functions, which means we need to use client components. In our case, we don’t want to transform our whole page to use client capabilities and have the whole tree in the client bundle; instead, we would prefer to use Server components and import our client components to progressively enhance our application. So, let’s create a separate component that will handle the client-side logic. Inside our app folder, let's create a components folder, and here, we will be creating our component: ` Let’s go ahead and initialize our component. I went ahead and added a button with some styles in it: ` And then import it into our Page Server component: ` Now, if we run our app, we should see the following: Awesome! Now, our button doesn’t do anything, but our goal is to record our audio and send it to someplace; for that, let us create a hook that will contain our logic: ` We will use two APIs to record our voice: navigator and MediaRecorder. The navigator API will give us information about the user’s media devices like the user media audio, and the MediaRecorder will help us record the audio from it. This is how they’re going to play out together: ` Let’s explain this code step by step. First, we create two new states. The first one is for keeping track of when we are recording, and the second one stores the instance of our MediaRecorder. ` Then, we’ll create our first method, startRecording. Here, we are going to have the logic to start recording our audio. We first check if the user has media devices available thanks to the navigator API that gives us information about the browser environment of our user: If we don’t have media devices to record our audio, we just return. If they do, then let us create a stream using their audio media device. ` Finally, we go ahead and create an instance of a MediaRecorder to record this audio: ` Then we need a method to stop our recording, which will be our stopRecording. Here, we will just stop our recording in case a media recorder exists. ` We are recording our audio, but we are not storing it anywhere. Let’s add a new useEffect and ref to accomplish this. We would need a new ref, and this is where our chunks of audio data will be stored. ` In our useEffect we are going to do two main things: store those chunks in our ref, and when it stops, we are going to create a new Blob of type audio/mp3: ` It is time to wire this hook with our AudioRecorder component: ` Let’s go to the other side of the coin, the backend! Setting up our Server side We want to use our models on the server to keep things safe and run faster. Let’s create a new route and add a handler for it using route handlers from Next.js. In our App folder, let’s make an “Api” folder with the following route in it: We want to use our models on the server to keep things safe and run faster. Let’s create a new route and add a handler for it using route handlers from Next.js. In our App folder, let’s make an “Api” folder with the following route in it: ` Our route is called ‘chat’. In the route.ts file, we’ll set up our handler. Let’s start by setting up our OpenAI SDK. ` In this route, we’ll send the audio from the front end as a base64 string. Then, we’ll receive it and turn it into a Buffer object. ` It’s time to use our first model. We want to turn this audio into text and use OpenAI’s Whisper Speech-To-Text model. Whisper needs an audio file to create the text. Since we have a Buffer instead of a file, we’ll use their ‘toFile’ method to convert our audio Buffer into an audio file like this: ` Notice that we specified “mp3”. This is one of the many extensions that the Whisper model can use. You can see the full list of supported extensions here: https://platform.openai.com/docs/api-reference/audio/createTranscription#audio-createtranscription-file Now that our file is ready, let’s pass it to Whisper! Using our OpenAI instance, this is how we will invoke our model: ` That’s it! Now, we can move on to the next step: using Llama 3.1 to interpret this text and give us an answer. We’ll use two methods for this. First, we’ll use ‘ollama’ from the ‘ollama-ai-provider’ package, which lets us use this model with our locally running Ollama. Then, we’ll use ‘generateText’ from the Vercel AI SDK to generate the text. Side note: To make our Ollama run locally, we need to write the following command in the terminal: ` ` Finally, we have our last model: TTS from OpenAI. We want to reply to our user with audio, so this model will be really helpful. It will turn our text into speech: ` The TTS model will turn our response into an audio file. We want to stream this audio back to the user like this: ` And that’s all the whole backend code! Now, back to the frontend to finish wiring everything up. Putting It All Together In our useRecordVoice.tsx hook, let's create a new method that will call our API endpoint. This method will also take the response back and play to the user the audio that we are streaming from the backend. ` Great! Now that we’re getting our streamed response, we need to handle it and play the audio back to the user. We’ll use the AudioContext API for this. This API allows us to store the audio, decode it and play it to the user once it’s ready: ` And that's it! Now the user should hear the audio response on their device. To wrap things up, let's make our app a bit nicer by adding a little loading indicator: ` Conclusion In this blog post, we saw how combining multiple AI models can help us achieve our goals. We learned to run AI models like Llama 3.1 locally and use them in our Next.js app. We also discovered how to send audio to these models and stream back a response, playing the audio back to the user. This is just one of many ways you can use AI—the possibilities are endless. AI models are amazing tools that let us create things that were once hard to achieve with such quality. Thanks for reading; now, it’s your turn to build something amazing with AI! You can find the complete demo on GitHub: AI Assistant with Whisper TTS and Ollama using Next.js...

Sep 27, 2024

8 mins

AINextJSJavaScript

How to Create Better Test Coverage Using Cypress 10

Testing is an integral part of software development, and it is important that all developers learn best testing practices. Jordan Powell, DX engineer at Cypress and Angular Google Developer Expert, has some tips to share with developers on how to write better tests using Cypress 10. In this article, we will take a look at Powell’s tips for writing end-to-end tests, component tests, and advanced testing patterns in Cypress. If you want to learn more from Jordan Powell, please check out his Advanced Cypress JS Drop training. Table of Contents - Why is Testing important? - Types of Testing - A new take on the testing pyramid - Differences between end-to-end testing and component testing - Jordan Powell’s best practices for E2E testing - Don’t use HTML Native selectors - Use Closures - Independent Test - Use Route Aliases - Setting a Global baseUrl - Jordan Powell’s Best Practices for Component Testing - Default Config Mount - Cypress Intercept - Use createOutputSpy - Jordan Powell’s Advanced Cypress Patterns - Session - Origin - Conclusion Why is Testing important? Software testing identifies issues within the application, and helps ensure that only high quality products are shipped to the user. Here are Jordan Powell’s reasons on why testing is important, and how it helps developers: Documentation: Good testing coverage will result in developers creating stronger test plans and better QA testing for new releases. Confidence: Writing good tests allows developers to build new features in confidence because the applications are working as intended. Safe Refactoring: Good test coverage leads to less refactoring down the road, and provides developers more time to work on new features. Improved UX: Good test coverage provides better UX (User Experience) for the end user because the application is working as intended. Types of Testing E2E, Integration, and Unit testing are three common methods for testing software applications. Unit Test: Unit testing serves as the foundation of the test pyramid. If you're working in a functional language, a unit will most likely be a single function. Your unit tests will call a function with different parameters and ensure that it returns the expected values. In an object-oriented language, a unit can range from a single method to an entire class. Integration test: Integration testing is where individual components of your application are tested as a group. End-to-end testing: E2E Testing is a technique that tests your app from the web browser through to the back end of your application, as well as testing integrations with third-party APIs and services. These types of tests are great at making sure your entire app is functioning as a cohesive whole. A new take on the testing pyramid In Jordan Powell’s Advanced Cypress JS Drop training, he challenges developers to rethink the traditional testing pyramid, and believes that component testing should also be included. Component Testing with Cypress 10 allows developers to test individual components quickly, regardless of its complexity. Component tests differ from end-to-end tests in that instead of visiting a URL to pull up an entire app, a component can be "mounted" and tested on its own. Differences between end-to-end testing and component testing Here are a few key differences between End-to-end and component testing: | End-to-end testing | Component testing | | ------------------------------------------------------- | ------------------------------------------------------------------------ | | The entire application and all of its layers are tested | Only the independent components are tested | | Testing can be done by developers and QA Teams | Testing is done by the developers | | Often requires a complex setup | No extra configuration for CI(Continuous Integration) environments needed | | Initialization command: cy.visit(url) | Initialization command: cy.mount() | Jordan Powell’s best practices for E2E testing Don’t use HTML Native selectors It is not good practice to use element selectors, id attributes, or class attributes when writing End-to-end tests. Using HTML Native selectors can lead to team members refactoring tests later on, or changing attributes which could affect the tests. Jordan Powell recommends using data attributes that can inform the team that this is a test attribute. When other team members need to change anything, they will be aware of the function of the attribute and what it may affect. Use Closures Jordan warns against assigned return values for Cypress assertions, and recommends using closures to access the Commands yield like this: ` Independent Test It is not good practice to combine related tests. Jordan Powell suggests that tests should be run independently from one another without sharing or relying on other test states. If test suites are related in any way, run the related properties or methods before each of the test runs, like in the code below: ` Use Route Aliases Another recommended practice is to use route aliases to guard Cypress against proceeding until an explicit condition is met. ` Setting a Global baseUrl It is bad practice to use hardcoded URL strings for the baseUrl because it will eventually fail when the environment changes. Instead, Powell recommends using a config file that holds the environment baseUrl. Jordan Powell’s Best Practices for Component Testing All of the code examples in this next section will be for Angular, but Cypress component testing works for all major Frontend JavaScript frameworks. Default Config Mount Component testing takes two parameters: the component to mount, and the object for configuration. A Custom Mount Config can boost flexibility. It ships a default mount config which you can use, but to manage multiple modules and import without adding too many boilerplate codes, it is recommended to have a custom mount config for specific instances. ` Cypress Intercept Component testing handles the individual components you are testing at a particular time, to access external API it is recommended to use cy.intercept. According to the Doc Cy.intercept can be used to passively listen for matching routes without manipulating the request or its response in any way. ` Use createOutputSpy When working with eventEmitter for components that may contain forms or other elements with events, createOutputSpy will automatically create an EventEmitter and set up the spy on it's .emit() method. ` Jordan Powell’s Advanced Cypress Patterns Session When testing for routes or components that require authentication Cypress provides cy.session which eliminates creating functions in your test to check for sessions on every call to the route or component. cy.session caches the sessions, and it will skip the login process for testing components that need the sessions on a second call. ` Origin Running tests for projects that require a visit to multiple different domains could get CORS, or a limitation of visits, due to browser environment. Cypress provides Origin to help bypass some of the browser limitations. ` Conclusion In this article, we looked at Jordan Powell’s tips for writing End-to-end tests, component tests, and advanced testing patterns in Cypress. I recommend watching the full video for Jordan Powell’s Advanced Cypress JS Drop training. Are you excited about the Cypress Component Testing? Let us know on Twitter....

Dec 19, 2022

6 mins

CypressTesting

Building a Stripe App: A Step-by-Step Guide to QR Code Generation

Building a Stripe App: A Step-by-Step Guide to QR Code Generation Why Build a Stripe App? I recently participated in an audio space with the Stripe team, and something they said really stuck with me: the Stripe app store is a growing area that isn't overly saturated yet. There's a lot of potential for new apps, and companies can use this opportunity to grow. I work at a company called This Dot Labs, and we've created several Stripe apps and even own one. After looking at the data, I can confirm that the Stripe team was right! Creating a QR Code Generator App For this tutorial, we'll build a QR code app that can take a URL and generate a code for it. This is a good use case to help you understand the ins and outs of Stripe's developer tools. Why QR Codes? QR codes are useful tools that have become common in e-commerce, restaurants, and other industries. While Stripe already has a QR code tool, we'll make our own to familiarize ourselves with their syntax and problem-solving approaches. Project Structure Before we dive into the implementation, let's look at the structure of our Stripe App QR Code project: * .vscode: Contains settings for Visual Studio Code * source/views: Holds the main application views * .gitignore: Specifies files to ignore in version control * stripe-app.json: Defines the Stripe app configuration * ui-extensions.d.ts: TypeScript declaration file for UI extensions * .build: this is where the built Stripe app gets placed. Step-by-Step Implementation 1\. Install Stripe Locally First, you need to install Stripe on your local machine. The documentation provides great instructions for this: * For Mac users: Use Brew to install * For Windows users: Download the package and add it to your environment variables You can find the details here in the stripe docs to install the Stripe CLI https://docs.stripe.com/stripe-cli When using Windows, you must do stripe login from Powershell, NOT from Git bash or any other tool. After the server is up, then you can continue using git bash for everything else. After stripe login, you need to enter stripe apps start. Once you do that, the server is up and running and you can go back to using git bash or any other tool. 2\. Install Dependencies We'll be using an extra package for QR code generation. Install it using npm: ` 3\. Set Up the Main Component Let's look at the home.tsx file, where we'll use Stripe's UI components: ` These components are similar to other UI libraries like Bootstrap or Tailwind CSS. 4\. Create the UI Structure Our app will have: * An input field for the URL * Validation using a regex pattern * Error handling for invalid URLs * QR code generation and display Here is the Home.tsx file that is located in the src/views folder ` * ContextView` is at the top level of the app where we see the Title and the link to the Stripe Docs that we placed in our Context View. * Box is how you use Divs. * Banners can be used to show notification errors or any other item you wish to display. * Textfields are input fields. * Everything else is pretty self-explanatory. 5\. Handle Content Security Policy One problem I personally ran into was when I tried to redirect users, the Stripe policies would block it since I did not express that I knew what it was doing. I had to go into the stripe-app.json file and mention the specific security policies. For this particular exercise, I kept these as null. This is my stripe-app.json file. ` 6\. Configure App Views As you can see here, the stripe-app.json file shows the views for each file I have. The Home.tsx file and the Invoice.tsx are also included This is our way of saying that for each view we have, show the app functionality on that page. Our stripe-app.json file will show it but also, the manifest.js file in our .build folder will also show the same. Any view that doesn't have a file will not show the application's functionality. So, if I were to go to transactions, the app would not show the same logic as the home or invoices page. By following these steps, you'll have a fully functional QR code generator app for Stripe. This is just a simple example, but the potential for Stripe apps is massive, especially for businesses serving e-commerce customers. If you need help or get stuck, don't hesitate to reach out, danny.thompson@thisdot.co. The Stripe team is also very active in answering questions, so leverage them as a resource. Happy coding!...

Dec 18, 2024

4 mins

stripe

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