Filip Hric

Walk through some of the capabilities of Cypress’ `.intercept()` command. Super useful tool, especially for testing hard-to-reach places of your app.

A Practical Guide to Intercepting Network Requests in Cypress

Clipboard or pasting text is not available in Cypress. But Cypress is pure JavaScript, so you can do anything that JS allows you to do.

Handling Copy and Paste in Cypress

Learn how to set up and test different network conditions using the Cypress intercept command.

Test Network Edge Cases with .intercept() Command in Cypress

With Cypress’ component testing, you can now take the best of both worlds. Render components and interact with them in a real browser.

Write, Test, and Debug Vue 3 Components in the Browser Using Cypress

Discord

GitHub

LinkedIn

Youtube

 Courses from Filip Hric

Vue (pronounced /vjuː/, like view) is a progressive framework for building user interfaces. Unlike other monolithic frameworks, Vue is designed from the ground up to be incrementally adoptable. The core library is focused on the view layer only, and is very easy to pick up and integrate with other libraries or existing projects. On the other hand, Vue is also perfectly capable of powering sophisticated Single-Page Applications when used in combination with modern tooling and supporting libraries.

Some components render differently based on the route they are rendered on. To use router within component tests, it is best to define its default values in `cy.mount()` function. Since we can customize this in any way we’d like, we can create a custom `path` attribute where we can pass our own routes and test our component behavior against them.

Test a Component Rendering Within Different Router Locations in Cypress Component Test

Every component test that uses Pinia needs to have Pinia imported and initialized. Instead of doing this separately for each test you can customize your `cy.mount()` command to automatically use a default store. You can further then customize it to use your own store in case you want to change its state.

Rewrite Cypress mount() Command to Provide a Default Store to all Components

Instead of calling an action function to change the state, we can choose to change it directly by importing the attributes from our store. In order to not loose reactivity while destructuring properties we can use `storeToRefs()` function.

Mutate Application State Properties Directly with Pinia’s storeToRefs()

Fast, easy and reliable testing for anything that runs in a browser.

cypress

When component uses a state management tool like Pinia, it needs to be defined within the test. To use Pinia inside the Cypress component test, we need to create a Pinia instance and pass it into our store. For changing the state we can call our actions directly from within our test and assert different attributes of the component with Cypress commands

Call Pinia Store Actions From Within a Cypress Component Test

`emit()` function enables components to communicate with one another. While this communication is a good candidate for end to end test, we can also test this in isolation within component. To do this, we’ll use `cy.spy()` function that will watch for the defined function call. Using this, we can confirm that our emitted event was actually invoked.

Use Cypress cy.spy() Function to Test a Vue 3 Component’s Emitted Events

By passing a `slots` option to our `cy.mount()` function, we can define content to be rendered inside our current component. We can use default or named components and eve use Vue’s `h()` function to create element and pass components with desired properties.

Render a Vue 3 Component with <slot /> and Test its Content Properties

Some components can have properties passed into them, For these, we can use an options parameter in our `cy.mount()` function and pass `props` attribute which will define the properties we want to pass into our component. This way we can test whether different properties correctly render out in our component.

Pass Properties Into a Vue 3 Component Within a Cypress Test

Importing styles is going to be essential for all of our components to render properly. We will do this similarly as we do in our application - at top level. `component.ts` file is the proper file for this, as this is the one that gets loaded before running our specs. Importing our `index.css` file here will make all of our components render with the correct styles.

Setup Global CSS Properties for Cypress Component Tests

To create our first test, you’ll create a spec file that pairs with the component. Usual naming convention is using `filename.cy.ts` (or .js), but this can be easily set up in `cypres.config.ts` file. After you create the spec file, you can mount the component by importing it and using cy.mount() command inside an `it()` block. This will render the component inside Cypress app, but will not load all the dependencies that the component needs, like css styles. These need to be imported into the spec file manually. Since we are running our component in a browser and inside a Cypress app, we can interact with it using common Cypress commands.

Mount and Test a Vue 3 Component in Cypress

To start with component testing in Cypress you need to open Cypress and go through setup wizard that will help you out with your first steps. It will take you through a couple of steps, where you’ll install dependencies and create important configuration. Most of this is done for you, but you can customize anything. In our application, we will be working with Vue 3 framework with Vite bundler.

Setup Vue 3 Component Testing in Cypress

Server may respond differently when providing a response to a logged in user. Usually, a user is identified when an authorization header is sent with the request. With .intercept(), we can dynamically add a header to a request and skip the login process. Server will provide the same response as it would when a user would go through login process.

Send Network Requests with Authorization Headers in an Intercepted Request with Cypress

When user waits too long, we might want to give them an option to reload page and try again. This is usually a hard case to reach and test effectively. But the .intercept() command provides us with a `throttleKbps` option that can limit the bandwidth, or we can use `delay` option that will delay our response for a given time.

Test Slow Network Conditions in Cypress by Throttling and Delaying Intercepted Requests

Servers sometimes use entity tags that identify a user and provide them with a cached response if needed. This can create ambiguity in your tests. To make your tests more stable, you can modify the request headers that take care of this caching. By deleting `if-none-match` header with `.intercept()` command, you will get a fresh response from server every time.

Prevent Response Caching in Cypress by Deleting 'if-none-match' Request Header

When a static response is not enough, we can take the real data from server and modify it to our liking. This saves a ton of time, because we don’t need to create the data ourselves. Instead, we can take e.g. response body and change only a desired attribute. This gives us one more advantage, because we can first make assertions on real data, and only then make changes. This is a great advantage compared to providing a static response, that essentially creates a blind spot for any API changes.

Dynamically Combine Real and Mocked Response Body Data in Cypress

When you don’t want to stub your response or create your data before the test, you can change the request your application makes altogether. If your server recognizes different queries, you can modify your request‘s URL and add a query that will specify what kind of data you want to get.

Dynamically Add Queries in Cypress Intercept Function Requests

When testing certain user stories, you may want to start with a clean state, but then return to the initial page and see the data you have created. This can be problematic if you are stubbing your requests. Luckily, you can limit how many times you a request should be intercepted.

Configure cy.intercept to Only Intercept a Network Request Once 

Instead of explicitly providing the exact body, you can choose to save the data you want to use in a separate file. When you create a file in the fixtures folder, you can reference it using `fixture` option in the .intercept() command. This will automatically look into the fixtures folder and load the data from the file.

Use a Fixture in Cypress to Provide Response Data to Network Requests

With .intercept() command, we can change the response body. This enables us to provide our own response instead of the real one coming from server. We can then test our application’s behavior under different situations and test different edge cases.

Change a Response Body with cy.intercept to Provide Your Own Data in an API Call

Frontend application can react differently to various server responses. One way to test the application behavior is to change response status code. .intercept() command in Cypress has the ability to stub the status code and error message that the server would provide on error.

Stub an API Request Status Code and Error Message with cy.intercept

You can simulate a network condition, where an http request does not make it to server. When that happens, you want to make sure the app is showing the user a correct message. By passing `forceNetworkError` attribute, you’ll be able to simulate such network conditions and see how application behaves under given circumstances.

Simulate a Network Error Using .intercept() Command

Approaching testing at a component level has definitely its benefits. Seeing your component rendered in isolation, and making sure it behaves correctly with different properties is definitely faster that trying to interact with an app at end-to-end level. On the other hand, seeing your app render in a browser in an end-to-end test is a significant advantage. 

With Cypress’ component testing you can now take the best of both worlds. Render component and interact with it in a real browser. You can pass different properties, spy on its function calls, click and type into them or even intercept its network calls. All this with a minimal setup and vast options.



## What you'll learn
- setup component testing in Cypress
- customize component mounting properties
- render a component in a browser
- examine a component with different passed properties
- make asserrtions on component’s emitted events
- render a component with content passed into its `<slot />`
- catch edge cases by calling actions and passing values into Pinia’s state
- handle router and it’s effect component behavior

Write, Test and Debug Vue 3 Components in the Browser Using Cypress

When comparing two visually similar websites, it can often be challenging to precisely identify the subtle differences between them. To facilitate a rapid analysis of these discrepancies, a practical technique involves leveraging Chrome's integrated developer tools to capture full-page screenshots of each site. Subsequently, these screenshots can be uploaded to a platform like AI Studio. There, the AI can analyze the images and generate a report detailing the variations. This entire process, leveraging a few quick shortcuts, can be completed in under a minute, delivering a comprehensive breakdown of the differences for efficient comparison and analysis.

Quickly Compare Two Sites Using AI Studio with Chrome Full Page Screenshots

It's fairly trivial to create a React project, but there's always a big hurdle between creating it locally and making it shareable so that someone else can run it. This lesson walks you through the process of automating creating a React project locally, creating the repository where it's going to be hosted, and creating shareable links where it can be run so that you can quickly and easily create single one-off demos and shoot them over to your friends and coworkers for sharing your code ideas in a working environment.


```bash
share-react-project() {
  if [[ -z "$1" ]]; then
    echo "Usage: share-react-project <project_name>"
    return 1
  fi

  local project_name="$1"
  local github_username=$(gh api /user --jq '.login')

  echo "Creating Vite project: $project_name"
  pnpm create vite "$project_name" --template react

  cd "$project_name"

  echo "Initializing Git repository"
  git init

  echo "Adding all files to Git"
  git add .

  echo "Creating initial commit"
  git commit -m "Initial commit"

  local codesandbox_link="https://codesandbox.io/p/github/${github_username}/${project_name}"

  echo "Adding CodeSandbox link to README.md"
  echo "" >> README.md
  echo "## CodeSandbox" >> README.md
  echo "[![Open in CodeSandbox](https://assets.codesandbox.io/github/button-edit-blue.svg)](${codesandbox_link})" >> README.md

  echo "Adding README.md to Git"
  git add README.md

  echo "Committing README.md changes"
  git commit -m "Add CodeSandbox link"

  echo "Creating GitHub repository: $github_username/$project_name"
  gh repo create "$github_username/$project_name" --public

  echo "Pushing to remote 'origin'"
  git push -u origin main

  echo "Project '$project_name' created successfully!"
  echo "GitHub repository: https://github.com/$github_username/$project_name"
  echo "CodeSandbox link: $codesandbox_link"
}
```

Automate Creating a Local React Project, GitHub Repository, and Live Hosted Demo in a Single Command

[Verdaccio](https://verdaccio.org/) is a fully featured NPM registry that you can run locally on your machine. It’s a great tool for testing your release process, running end-to-end tests, and simulating real-world scenarios like deploying packages, installing them, and verifying functionality as an end user would.

Nx includes a [generator](https://nx.dev/features/generate-code) that simplifies setting up Verdaccio. To configure it, run:

```shell
npx nx g @nx/js:setup-verdaccio   
```

This command installs the necessary NPM packages and creates a `project.json` file with a `local-registry` target. To start the local registry, open a new terminal window and run:

```shell
npx nx local-registry
```

This will:
- Launch the Verdaccio registry.
- Configure NPM to point to the local Verdaccio server at `http://localhost:4873`.

> **Note:** A `project.json` file provides an advanced way to define scripts, offering more flexibility than a traditional `package.json` for managing complex targets.

Setup local Verdaccio server to release NPM packages

Learn how to spin up a local NPM registry powered by Verdaccio to test deploy your NPM packages.

In TypeScript, developers often begin by defining the structure of their data using type definitions or interfaces, which is a powerful way to ensure type safety. However, as applications grow and become more complex, simply defining the shape of an object might not be enough to guarantee its consistent creation and behavior throughout the codebase. This often leads to situations where objects that are intended to be of a certain "type" might be missing crucial properties or have incorrect data, which can be difficult to track down and debug.

This lesson tackles the question of when and why to move beyond basic type definitions and embrace classes in TypeScript. It demonstrates how classes provide a more robust mechanism for defining object structure, enforcing type constraints, and ensuring consistent object creation. By establishing a clear blueprint for objects, classes not only improve compile-time type safety but also offer runtime benefits and better code organization, ultimately helping developers avoid common pitfalls associated with loosely structured objects in larger TypeScript projects.

Stop Avoiding Classes in TypeScript

Karabiner isn't only for your keyboard. It can also hijack your mouse buttons and enable them to be similar to layers on your keyboard, where holding down a mouse button can allow you to tap keys on your keyboard to trigger commands and macros that can completely revolutionize your workflows. For example, you can hold down the right mouse button and tap on R to go to references in VS Code. Or hold down the right mouse button and tap the left mouse button to chop up videos and Screenflow.

This completely unlocks a whole new world of possibilities and use cases for your mouse as you can hover your mouse over anywhere on the page. And just tapping keys on your keyboard allows you to trigger mouse actions, to trigger keyboard actions, or to trigger macros and applications and terminal commands. and anything that your imagination can come up with. 

Karabiner: Rethinking Right-Click as a Macro Command Center

Make an HTML table more readable on mobile devices by using the ::before pseudo-element. We add labels to each cell, so they appear like cards when the table is viewed on smaller screens. The ::before content is set using a data-label attribute for each cell to enhance mobile viewability without horizontal scrolling.



Create a mobile friendly table with the before pseudo-element

Learn to use CSS ::before pseudo-element for mobile-friendly HTML tables. Add labels to cells for enhanced readability on mobile, avoiding horizontal scroll.

Any app of a decent size has event flows and messages being passed around. At a certain point it becomes complicated to explain it through prose and you want to turn towards diagrams. Now setting aside the time to create diagrams that accurately describe what's happening in your codebase can be quite time consuming. Luckily, with today's AI tools, we can now just do basic walkthroughs with rough recordings over codebase dictating what's going on along the way and then upload that to tools like AI Studio and then ask it to generate diagrams in a text-based format such as Mermaid that will then generate the flowcharts and diagrams for us. So this video walks us through this process of recording a rough video, uploading it to AI Studio and then asking AI Studio to generate the proper Mermaid diagram syntax.

Generate Mermaid Flow Chart Diagrams with Gemini 2.0 from Rough Screen Recordings

I'm a diehard Karabiner user and anytime I start doing something repetitively I always move it into my Karabiner configuration. Sometimes I'll fall into scenarios where I want to trigger a command, but I also want to know if that command succeeded or failed. Since Karabiner can trigger any command, setting up the command is fairly straightforward, but knowing whether it succeeded or failed became much more difficult. Luckily for me there is a package called terminal-notifier that you can install from homebrew and you can pipe the output of your command to terminal-notifier. And have a seamless way of triggering your keyboard shortcut which runs a command and you can be notified of the results.

Use Karabiner to Trigger a Terminal Command and Get Notified of the Results

There are a lot of scenarios when inspecting a site in Chrome where you don't want any click events to fire and you don't want any scripts to run. Or maybe something is animating in and out of the page and you want to capture it at a certain moment. This is a great use case for pausing script execution, which is kind of using the debugger manually by going into the Chrome DevTools and the Sources tab and clicking the pause button to essentially pause the entire page. This will give you a chance to inspect any of the elements and styles you want to inspect. And you don't have to worry about fire and click events or anything that might interrupt your investigation into the elements and styles that you want to find.

Pause Script Execution in Chrome to Easily Inspect Elements

Gemini 2.0 has a context window of a million tokens, and this means that you can upload hundreds of files and allow it to inspect and analyze massive refactors across entire code bases. 

This lesson demonstrates concatenating an entire code base into a single file and then uploading it to AI Studio. Once within AI Studio, we ask it to find the types of tasks that it can evaluate for us. Then we select one of the tasks and ask it to generate instructions for that task. Once those instructions are complete, we then turn them over to Windsurf's Cascade agent, and we allow Windsurf's Cascade to do all of the work for us as we sit back, relax, and let the AI do our jobs.