Learn Ionic, Jest and Openapi

Get started building web applications with Angular and Firebase.

In this course, you'll learn how to set up and use Firebase in your Angular applications using the AngularFire library.

We choose the AngularFire library because it is an official library created by the Firebase and Angular teams to work better with Angular.

It helps you by wrapping everything into observables and helps update zones. 

By the end of this course, you'll be able to build web applications using Cloud Firestore as your database, Firebase Authentication as your Auth system, Cloud Storage to save files, and Firebase Hosting to deploy your applications to the web.

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

typescript

Build Full Stack Web Applications with Angular and Firebase

Ionic is the beautiful, free and open source mobile SDK for developing native and progressive web apps with ease.

ionic

Now that file uploading works, we want to actually show that a task has files associated with it. To do this we will need to update the task object with a file property that we'll push files too.

In this lesson, we'll use Cloud Storage methods like getDownloadUrl() to get the file's download URL from our bucket.

Then we'll add that file's information to our task and persist it in the database to show the list of files in a task to the user.

While we do this, you'll see how we can easily add a spinner when files are being uploaded using Ionic loadingController.


Save and Display Tasks Files Utilizing Firebase Cloud Storage getDownloadUrl

A scenario you will inevitably run into is users needing to reset their passwords for security reasons or they lost and forgot their password.

We'll learn how to send our users an email to reset their passwords, after we send the email, we'll display a notification alert with ionic alertController to the user and redirect them to the login page.


Send a Password Reset Email Using Firebase Authentication with sendPasswordResetEmail

Now it's time to create a template for our authentication page using Ionics page generation CLI.

We'll show how to use the same page for all of our authentication operations by reading the parameters from the URL and displaying the right form elements and buttons depending on the parameters present.


Create an Authentication Page Template with Ionic Page Generation

We'll learn how to delete documents from the database. This action is pretty straight forward, we'll add a delete button that will call Firestore `deleteDoc` and pass in the task id.

We'll also explore a good practice when performing destructive operations (__like deleting database objects__) of adding a confirmation step to make sure our users don't delete objects by accident. We'll do this with the Ionic Alert Controller.


Delete a Document with a Confirmation Step from Firestore

We'll evaluate 2 good practices when adding a new task.

First, we'll show the users a toast alert to notify them that their document was saved in the database. We'll do this with a toast component that ionic makes available to us

And second, we'll use Angular's router to navigate the user back to the task list.

Notify Users Their Database Operation Worked with a Toast Alert

We'll create the template for our new page and set everything up so that we can use this page to create new tasks. The first thing we will do is create a BehaviorSubject task variable that we'll store form values in to send to Firebase.

Because we are using the ionic framework we'll lean heavily into this when creating our templates. You'll see how we bind text values to the object we'll send to Firebase as well as a selector component that will use `ion-segment`.

We'll also see a tip on handling the `async` pipe in a top container in our template so that we don't have to manually add it everywhere we'll render a property from an observable


Create a New Task Form Page Template with Ionic

firebase

There are 2 different ways to get a document's ID when using `@angular/fire`.

You can add the parameter `{ idField: 'id' }` to your collection when using the `collectionData()` observable.

You can also use the observable `collectionChanges()` and access the internal metadata of the document to manually get the ID and add it to the resulting object.

Code sample: https://github.com/javebratt/angularfire-idField

Access a Firebase Document's ID Even when It's Not Stored in the Document with angularfire

jest

Jest is a fast and safe testing framework with a focus on simplicity. 
This lesson will walk you through how to add jest to your application by running `yarn add --dev jest` followed by updating your `package.json` to be able to run your tests on the console by using the `yarn test` script.
This lesson covers how to create your first test by creating your first block that groups several related tests with `describe` and then adding your first test method using either the `it` or `test` keyword.

Add Jest to Your Application and Create Your First Test

The pluggable linting utility for JavaScript and JSX.

eslint

We can leverage GitHub Actions to automate the running of all of our accessibility auditing tools as part of a Continuous Integration (CI) workflow. 

Auditing tools will only catch a percentage of potential accessibility issues, it is no replacement for manual testing.  But being able to automate the auditing will add efficiencies to our testing and provide an early warning system that can be run much more frequently than it’s practical to perform manual testing.  Additionally, we can use our CI suite as a safety net to prevent code changes that break accessibility from being able to be merged.

## Resources
* https://app.egghead.io/lessons/react-set-up-eslint-to-audit-accessibility-issues-in-react
* https://docs.cypress.io/guides/continuous-integration/github-actions#Basic-Setup
* https://github.com/cypress-io/github-action

Automate Accessibility Audits with GitHub Actions

React is one of the web’s most popular frameworks for building JavaScript applications. 

If you know what you’re doing, React can drastically simplify how you build, use, and maintain code.

Whether you’re a React newbie or you’re ready for advanced techniques, you can level-up with egghead. Explore our in-depth courses, lessons, and community resources to build more powerful applications and crack open your career.

react

We can add accessibility testing to our `jest` unit tests with `jest-axe` which gives us:

* An easy way to automate accessibility auditing
* the flexibility to audit at any level of our code, as low as an element and as high as a component representing an entire page of our app
* A safety net for any accessibility regressions

Here we'll see how to use `jest-axe` with `react-testing-library` to render the components for `jest-axe` to audit for accessibility.

The React Testing Library is a very light-weight solution for testing React components. It provides light utility functions on top of react-dom and react-dom/test-utils, in a way that encourages better testing practices.

## Resources
* jest-axe: https://github.com/nickcolley/jest-axe
* react-testing-library: https://testing-library.com/docs/react-testing-library/intro/

Write Better Unit Tests with react-testing-library and jest-axe

We can add accessibility testing to our `jest` unit tests with `jest-axe` which gives us:

* An easy way to automate accessibility auditing.
* The flexibility to audit at any level of our code, as low as an element and as high as a component representing an entire page of our app.
* A safety net for any accessibility regressions.

Here we'll see how to use `jest-axe` with `enzyme` to render the components for `jest-axe` to audit for accessibility.

Enzyme is a JavaScript Testing utility for React that makes it easier to test your React Components' output. You can also manipulate, traverse, and in some ways simulate runtime given the output.

## Resources
* jest-axe: https://github.com/nickcolley/jest-axe
* enzyme: https://enzymejs.github.io/enzyme

Write Unit Tests for Accessibility Using jest-axe and enzyme

We can add accessibility testing to our `jest` unit tests with `jest-axe` which gives us:

* An easy way to automate accessibility auditing.
* The flexibility to audit at any level of our code, as low as an element and as high as a component representing an entire page of our app.
* A safety net for any accessibility regressions.

Here we'll see how to use `jest-axe` with `ReactDOM` to render components for `jest-axe` to audit for accessibility.

## Resources
* https://github.com/nickcolley/jest-axe

Render Components with ReactDOM to Write Tests with Jest and jest-axe

Best practices for building & testing redux applications have changed dramatically over time. This course aims to be a comprehensive yet understandable resource for those seeking to improve the testing of their redux applications.

This course is broken up into three parts.

The intro is look at how to add jest to an existing react redux application that was built on top of [vite](https://vitejs.dev/). We cover basic functionality like [watch mode](https://jestjs.io/docs/cli#--watch) and generating and using [code coverage](https://jestjs.io/docs/cli#--coverageboolean) to inform our testing strategy.

The first section covers the specifics of unit testing the redux code in our application. We'll go over how to test reducers, selectors and thunks. As part of this we'll touch on mocking APIs and using [Redux Mock Store](https://github.com/reduxjs/redux-mock-store) as well as running actions through our applications' actual reducers to broaden our test coverage.

Finally we'll look at how we can test our redux connected react components using the various utilities that come with the [React Testing Library](https://testing-library.com/docs/react-testing-library/intro/). We'll cover simulating various kinds of user input with the [user-event module](https://testing-library.com/docs/ecosystem-user-event), populating our redux store with test data, using [jest spy](https://jestjs.io/docs/jest-object#jestspyonobject-methodname), how to wait for asynchronous tasks to complete, and several approaches for finding & asserting that visual elements exist on the page.

This course is built on top of content that was created for the [Modern Redux with RTK and TypeScript](https://app.egghead.io/playlists/modern-redux-with-redux-toolkit-rtk-and-typescript-64f243c8) course and I highly recommend you start there if you haven't completed it already. 

I'm confident you will level up your redux testing abilities if  watch these lessons and practice coding each of them as you go.

Intro to Confidently Testing Redux Applications with Jest & TypeScript

Intermission Pep Talk - Testing Redux Applications

The [reselect module](https://github.com/reduxjs/reselect) popularized a pattern of memoized redux selectors. Now that pattern is baked into Redux Toolkit with its [createSelector](https://redux-toolkit.js.org/api/createSelector) method, which is used by the `getMemoizedNumItems` selector we're testing here.

Any selectors created with `createSelector` come with these two additional methods `recomputations()` and `resetRecomputations()`. These methods keep track of how many teams your data was recomputed and are essential for testing these selectors.

Some additional examples on testing memoized selectors can be found here:
https://github.com/reduxjs/reselect#q-how-do-i-test-a-selector



----

The createSelector method first takes any number of "input selectors" which gather data from your redux store and then for its final arguments takes an additional selector which has for its inputs the result of those input selectors.

The memoization is broken if either the initial state is unchanged OR if the any of the  results of the input selectors are unchanged. It uses `===` equality and not any sort of nested equality checking so `state` and `{ ...state }` would not be considered the same and always would recompute. On the flip side passing in `state` and then running `state.count++` would not trigger a recompute automatically, because the `state` object reference has not changed and `===` would pass. It definitely tripped me up a few times, so keep an eye out for issues with this.




Unit Testing a Memoized Redux Selector Built with Reselect/RTK

Redux is a predictable state container for JavaScript apps.
It helps you write applications that behave consistently, run in different environments (client, server, and native), and are easy to test.

redux

There are several ways to mock APIs for our tests.

Here we're using [jest.mock](https://jestjs.io/docs/es6-class-mocks#calling-jestmock-with-the-module-factory-parameter) with the module factory parameter to a new mocked module to replace our original. This helps us avoid problems like servers taking a long time and node.js not having fetch built-in.

When using mocks this way it's important to note that this mocked module is only going to show up for the tests executed in this file. Other test suites will continue to receive the original implementation of app/api. 

Other approaches to mock APIs include mocking out `window.fetch` or using [Mock Service Worker](https://mswjs.io/docs/getting-started/integrate/node) to provide a more robust API implementation. However, the approach we took here makes sense for our use case. We have a simple API surface, it lives in a single file, we never call `fetch` directly and we don't need a lot of bells and whistles (like responding to different routes or query parameters). So for that reason this approach and the [spyOn](https://jestjs.io/docs/jest-object#jestspyonobject-methodname) approach used in some of the later lessons actually works really well.

If you're using [Apollo](https://www.apollographql.com/) or [ReactQuery](https://react-query.tanstack.com/) or [SWR](https://swr.vercel.app/) to handle your data, then you almost certainly should use [Mock Service Worker](https://mswjs.io/docs/getting-started/integrate/node) instead of the jest.mock approach.

Mocking out our API Helper with jest.mock

Code coverage is an important part of any test setup. One of the jest framework's innovations is built-in test coverage support. In this lesson I demonstrate using the [collectCoverageFrom](https://jestjs.io/docs/configuration#collectcoveragefrom-array) configuration option to improve jest's coverage support for TypeScript files and then demonstrate using `npx jest --coverage` to run code coverage as well as `npm test -- --coverage`, which does the same thing.

At the end I briefly mention the [collectCoverage](https://jestjs.io/docs/configuration#collectcoverage-boolean) flag which seems like you'd want to always just have on, but in practice is annoying. That's because coverage takes several extra to process and I rarely need my code coverage run, so it just makes the testing feedback loop a lot slower. For a build-only config it might make sense to leave on.

----

There's a [pretty good question on stackoverflow](https://stackoverflow.com/questions/43046885/what-does-do-when-running-an-npm-command) that covers using `--` with `npm test` that you might want to check out.

Here's an explanation of [how npx differs from npm](https://medium.com/@maybekatz/introducing-npx-an-npm-package-runner-55f7d4bd282b).


Configuring Code Coverage for TypeScript Files in Jest

Jest has a [watch mode](https://jestjs.io/docs/cli) that can really speed up test development. It will automatically run your tests as you save your test files. And it has a built-in pattern option to allow you to only focus on tests for a particular file. This approach works well in combination with [test.todo](https://jestjs.io/blog/2019/01/25/jest-24-refreshing-polished-typescript-friendly#testtodo) where you can stub out a number of tests and then code on them until they all pass.

Most of what is being done in these tests we've already seen before and it's important to note that I'm doing only the most basic of testing here. For each of these actions it wouldn't be uncommon in production to have 3-6 tests instead of just one.

It's important to note that `it` and `test` are aliases of one another so `it.todo` and `test.todo` both work seamlessly and are just a matter of preference. *Usually* when I'm doing unit testing I'll stick with `describe` and `it`, which commonly go together and I use `test` without `describe` when I'm testing react components with [React Testing Library](https://testing-library.com/docs/react-testing-library/intro).

Using Jest in Watch Mode with test.todo to Test a Redux Reducer

The app is built on top of [vite](https://vitejs.dev/) instead of the more popular [create react app](https://reactjs.org/docs/create-a-new-react-app.html). The benefit of vite is that it installs and builds extremely quickly. One of the downsides of vite is that it doesn't come with any out-of-the-box testing support. It also has its own [esbuild-based compiler](https://vitejs.dev/guide/features.html#typescript), which is not currently compatible with jest, so we have to configure JSX & TypeScript support for jest even though `vite` handles that already for our app.

This lesson requires installing a handful of modules:
```
npm install -D jest
npm install -D @testing-library/react @testing-library/jest-dom @testing-library/user-event
npm install -D @babel/preset-react @babel/preset-typescript @babel/preset-env
npm install -D identity-obj-proxy
```

Each of them serves an important purpose:

- [jest](https://jestjs.io/) _runs our tests_
- [@testing-library/react](https://testing-library.com/docs/react-testing-library/intro) adds the ability to render react components inside of our test environment
- [@testing-library/jest-dom](https://github.com/testing-library/jest-dom) _allows us to assert that components are in the DOM and contains certain text and classes_
- [@testing-library/user-event](https://testing-library.com/docs/ecosystem-user-event) _allows us to interact with rendered components programmatically_
- [@babel/preset-react](https://babeljs.io/docs/en/babel-preset-react), [@babel/preset-typescript](https://babeljs.io/docs/en/babel-preset-typescript), and [@babel/preset-env](https://babeljs.io/docs/en/babel-preset-env) allow us to use ES6 Modules, JSX, and TypeScript in our tests
- [identity-obj-proxy](https://github.com/keyz/identity-obj-proxy#identity-obj-proxy---) is helpful when rendering CSS modules so that we can see the original class names instead of obfuscated ones

We also have to add numerous config files such as `babel.config.js` and `jest-setup.ts` which are required to enable all of this functionality.

We put our `jest` config in our `package.json` file which works well, but you can also put it in a file named `jest.config.ts` or `jest.config.js`. See the [Jest Configuration Documentation](https://jestjs.io/docs/configuration) for more details about configuring jest.



Adding Jest with TypeScript Support to a Vite Application

In this lesson we go after the elusive goal of 100% test coverage by testing a few additional cases: error responses, empty error messages and the pending state that should exist between checkout being clicked and the API returning data.

The first two require special handling in our mock API:

```typescript
if (items.evilItem > 0) throw new Error();
if (items.badItem > 0) return { success: false };
```

In some ways these are arbitrary examples that may not exist in your other applications, but I wanted to demonstrate the fact that there are a lot of different ways an API might decide to communicate errors.

In general with AJAX calls a non-200 status response often gets thrown as an error and treated as an error case, but some APIs (such as graphql) include errors as part of a normal `200` response and need special handling. These lessons are meant to demonstrate what that might look like in your mocks.

Now it's useful to reiterate here that our simple API interface makes writing these mocks very easy, but in many cases something like [Mock Service Worker](https://mswjs.io/docs/getting-started/integrate/node) is a more appropriate way to mock out an API.

For our "pending" test, it's interesting what we lose when we stop focusing on actions fired (like in our previous 2 lessons) and instead focus purely on the resulting state. It makes looking at the intermediary state a bit more difficult. Here we work around that by calling `store.dispatch(thunk)` and saving the results of that to an `action` variable, which we `await` after doing an initial assertion. That `await` triggers our mock API to respond, so we can use the space between `dispatch` and `await` to peak into the pending state.

Additional Redux Thunk Unit Tests for Increased Code Coverage

Speed up your bug-fixing process dramatically with Cursors Composer. Take a warning from your logs, search for relevant terms, then seamlessly import both the warning and search results into Composer. Add documentation and apply fixes to all search results in one go. This streamlined workflow resolves multiple issues rapidly, saving valuable development time.

Batch Fix Every File in Search Results with Cursor's Composer

 We map over the initial set of results then use `Promise.all` to efficiently fetch the details of each pokemon rendered in the table. This allows us to add more columns to our pokemon table.

Fetch and display row details with Promise.all in Tanstack Table

map over the initial set of results then use `Promise.all` to efficiently fetch the details of each pokemon rendered in the tanstack table

Create a custom hook to fetch remote data by passing a promise to the React 19 `use` hook. Then render this data in Tanstack Table by memoizing the results and passing them to `useReactTable`.

Render remote data in a Tanstack Table with React 19's use hook and a promise

Create a custom hook using React 19’s use to fetch data with a promise. Render it in a Tanstack Table by memoizing and using useReactTable.

You know when you're deep in the code trenches and need someone to challenge your assumptions? That's exactly what this is about.

Instead of waiting for someone to poke holes in your master plan, you can paste that strategy straight into AI Studio and let it pressure test your ideas. We're talking about using this tool to validate everything from your feature proposals to your ambitious refactoring strategies.

The real magic happens when you hit that microphone button. Now you're in a real-time verbal sparring match. It's like rubber duck debugging but the duck actually pushes back and makes you defend every architectural decision you've made.

Here's the workflow:
1. Drop your master plan into the system instructions
2. Tell the AI to challenge every assumption
3. Hit that mic and defend your choices like you mean it
4. Watch your plan either emerge stronger or get rightfully dismantled

This approach is perfect when you're:
- Stuck in your own head with a complex problem
- Need to validate if your approach holds water
- Want to catch edge cases before they catch you
- Looking for opportunities you might have missed because you're too close to the code

It's like having a senior dev on call 24/7, ready to challenge your ideas and push you to think deeper about your solutions.

Now go forth and get your ideas challenged. Your projects will thank you for it.


An Uncomfortable and Challenging Conversation with AI Studio

In this lesson, you'll learn how to effectively brainstorm your project ideas before working with AI agents. We'll cover:

1. The importance of having a clear plan before starting work with AI agents
2. Using traditional brainstorming techniques to gather your thoughts
3. Leveraging video recording to capture your brainstorming session
4. How to review and analyze websites for inspiration
5. Documenting likes, dislikes, and potential features for your project
6. Using AI tools (like AI Studio) to organize and process your recorded brainstorming session

The lesson emphasizes a modern approach to brainstorming that combines traditional techniques with video recording, making it easier to later process your ideas through AI tools. This method helps ensure that no ideas are lost and that your thoughts can be effectively organized by AI for future reference.

How to Brainstorm Your Project Features to Prepare for AI Agents

fast-check allows us to create composite generators that suit our testing needs. We'll generate two numbers to create a point simulating an X and Y and assert that the distance should always be greater than or equal to 0.

Generate composite objects with fast-check fc.record

Just using fast-check by itself can make you tests verbose and tough to read. Lucky for us there are many integrations with fast-check such as the `@fast-check/jest` package that will help remove some boilerplate from our test.

Tidy up your test with @fast-check/jest

Many people share .cursorrules files, but trying to craft your own from scratch is a huge pain. Instead, this lesson shows you how to grab ALL community-created .cursorrules files to build a custom rule set for your projects. We'll use Gitingest and Google AI Studio to gather these examples and generate an awesome starting point customized to your specific project.

Generate Custom .cursorrules for Your Project Based on Community Examples

The GitHub CLI allows you to search issues and filter on different criteria like amount of comments. This allows you to search for real-world situations and pains/solutions people have using different technology. 

With the GitHub CLI in hand we'll drop 100s of issues as context in Googles AI Studio and have Gemini determine the 10 most frequently asked questions. This will give us a sense of how people use a library and where people get hung up.

Search 100s of Issues with GitHub CLI as Context for AI Studio

I often find myself wondering how to use certain APIs in certain situations, and I have a couple of keywords that I try and search up on Google. 

What you can do in this situation is turn to GitHub and see how other people have actually used this code on public projects. The GitHub CLI enables us to run searches like this, and we can take the results and work on them programmatically.

Inside of Cursor with their Composer AI agent, we can search for the files we want, tell the agent to download them, and inspect them for better understanding of how those things work together.