Learn Ampt, Javascript and Node

JavaScript® (often shortened to JS) is a lightweight, interpreted, object-oriented language with first-class functions, most known as the scripting language for Web pages, but used in many non-browser environments as well such as node.js or Apache CouchDB. It is a prototype-based, multi-paradigm scripting language that is dynamic, and supports object-oriented, imperative, and functional programming styles.

javascript

The new [cause](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error/cause) data property that you can add to a thrown `Error` can be used to retain access to the original error caught in a promise rejection. 

Improve Application-wide Error Handling rethrowing JavaScript Error with the Error Cause

You can finally make your numbers more readable in JavaScript. Add underscores in all types of numbers including BigInt, floats, hexes, octals, and binary to improve their readability. 

Just don't add the underscores to the beginning or end!

Make JavaScript Numbers more readable using Numeric Separators

[Promise.any](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/any) takes an iterable of promises and returns a promise that fulfills with the first promise that fulfills, and rejects when ALL of the promises in the iterable reject. 

[Promise.allSettled](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/allSettled) takes an iterable of promises, and returns an array of objects. The objects have a `status` property which is a string that is either `"fulfilled"` or `"rejected"`. If the `status` is `"fulfilled"` the object will contain a `value` property with the resolved value of the promise, and if the `status` is `"rejected"` the object will have a `reason` property with the reason for the promise's rejection. 

Manage Asynchronous JavaScript code with any, allSettled new Promise Methods

If we want to be able to modify the state of a promise from outside the constructor, we can use the [Promise.withResolvers](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/withResolvers) method to get access to the promise, and its `resolve` and `reject ` functions. 



Manually settle a promise using Promise.withResolvers

The [Logical Assignment Operators](https://github.com/tc39/proposal-logical-assignment) bring syntactic sugar over verbose syntax which enforced us to write explicit `if` statements. Thanks to the new operators `||=`, `&&=` and `??=` we can express the conditional logic in a more concise way.

Simplify JavaScript code with Logical, Assignment and Optional Operators

The new [Array.with](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/with) method gives you an immutable syntax for changing values of an array at a specified index. 

Sometimes `.map` will be more efficient. So, in this lesson we'll compare both methods while replacing an object at a specific index.


Simplify array immutable changes with the new array.with method

You no longer need to write generator functions to create basic lazy iterator functions.

Now, ECMAScript supports iterator helpers that you can call on `Array.values()`. With these helpers, the values of an array will be operated on lazily, and will only run when the values are needed.



Make JavaScript computations lazy using Iterator Helpers

The ["Set Methods"](https://github.com/tc39/proposal-set-methods) proposal introduces 7 new methods to JavaScript/ECMAScript:
- `union`
- `intersection`,
- `difference`,
- `symmetricDifference`,
- `isSubsetOf`
- `isSupersetOf`
- `isDisjointFrom`

Thanks to them, complex operations using JavaScript sets will become much easier.

Perform Set Operations using JavaScript Set Methods

Finding elements starting from the end of an array has gotten a lot easier with the introduction of the `at`, `findLast`, and `findLastIndex` methods!

With `at` you no longer need to remember to access the end of the array like `array[array.length - 1]` trick. You can just call `.at[-1]` to get the last element!

`findLast` and `findLastIndex` work the same as their `find` and `findIndex` counterparts. But, they work backwards from the end of the array. This is useful if you know what you're accessing is going to be closer to the end.

Find Items from the end of the JavaScript Array using at, findLast and findLastIndex

[Array Grouping](https://github.com/tc39/proposal-array-grouping) is the new feature of JavaScript/ECMAScript, which splits an array (or, generally, an iterable), into smaller sub-arrays. Grouping is different than other JS array methods - it's *not* a part of the array prototype, but a static method.

Group data by keys using JavaScript Array Grouping (Object.groupBy)

Learn how the latest JavaScript features can help you improve your codebase. 

Learn the Latest ECMAScript Features (ES2024, ES2023, ...)

Next.js is a minimalistic framework for server-rendered React applications.

Define where Keystatic should store your content

In this video, you'll write some logic to toggle between local and Cloud storage modes for Keystatic, based on whether the site is running in development or production mode.

Change The Keystatic Storage Mode Based on NODE_ENV

In this video, you'll learn how to manually configure Keystatic to work in GitHub mode. 

You'll walk through the GitHub App creation flow, and then copy the environment variables over to the deployed instance to be able to edit content remotely.

Manually Connect a Keystatic Project To A GitHub Repo

In this video, you'll connect your project with Keystatic Cloud, so that content can be created and edited directly from the deployed URL.

No need to touch the codebase — the changes integrate directly with the GitHub repository!

Setup GitHub Collaboration With Keystatic Cloud

In this video, you'll add a generateStaticParams function in the individual author page, so that a static HTML page is generated at build time, so we can access those on Vercel.

Generate Static Pages From Keystatic Entries With generateStaticParams in Next.js 14

Node.js is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.

node

In this video, you'll deploy the Keystatic project to Vercel. You'll find out that not everything is working properly — and there are two different ways (both covered in the next videos) we can improve the situation.

Deploy a Keystatic Project To Vercel

In this video, you'll change the logo and site title for the Keystatic Admin UI, by using the brand options in the User Interface settings of the config file.

Change The Site Title and Logo In The Keystatic Admin UI

In this video, you'll customise the Keystatic Admin UI Navigation Sidebar and Dashboard by using the User Interface options in the config file.

Customise the Keystatic Admin UI Navigation Sidebar And Dashboard

In this video, you'll create a Keystatic Singleton to store social media links for the site's footer.

You'll also render these links in the root layout of the Next.js site.

Creating One-Off Datasets with Singletons in Keystatic

In this video, you'll discover how you can switch the Keystatic Admin UI to a "zen mode" content-focused layout for a given collection or singleton, by setting the Entry Layout option to "content".

Switch To a Content-Focused Layout In Keystatic



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


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

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

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

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

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

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

Effective Runtime Type Checks with Zod


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

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

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



Mocking WebSocket APIs with Mock Service Worker


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

Always Name Functions in JavaScript


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

Import the Same JavaScript Module Multiple Times with Cache Busting



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

Use GitHub Actions Matrix Include for Complex Job Configurations

While running `zod` schema validation agains domain-rich objects, the error message saying that _a string is not a number_ might not be really useful.

Especially, when you need to provide a meaningful feeback to the user, e.g. after they have submitted a form with lots of data.

`zod` allows to customize messages on a very granular level. We can also extract repeatable customization to `zod` error maps.

Finally, in order to process an error message further (e.g. display it to the user), we need to handle the `zod` validation errors effectively. Especially, when a big object validation has failed and we could receive a handful of errors.

That's what we learn in this lesson. 🔥

Customize zod Error Messages and Handle zod Errors Effectively

customize zod validation messages, customize zod schema property messages, reuse error maps across different schemas, navigate through zod error objects

You might want to run `zod` schema checks in different styles.

Sometimes you prefer to conditionally throw the error - that's what `parse` does. But another time you'd prefer to receive a `boolean` property that determines whether the validation was successful or not - and perform further actions accordingly.

Additionally, the error-throwing API of `parse` works extremely well with [TypeScript assertion functions](https://www.typescriptlang.org/docs/handbook/release-notes/typescript-3-7.html#assertion-functions). Their combination is just... perfect! 👌

That's what we learn in this lesson.

Use parse and safeParse Runtime Type-checks with zod

use zod parse function to conditionally throw ZodError, use zod safeParse to get a boolean value and run typescript type guard over success property

In this lesson we learn that TypeScript cannot guarantee correct shapes of responses. That's due to TS performing checks in compile-time, while the response will be availbale in runtime - when TS doesn't exist anymore.

In some situations, such as HTTP requests, runtime type checks such as `zod` are essential for providing quick feedback around data-related errors.

Understand where are the possible mistakes to make while using TypeScript with HTTP calls. Use `fetch` and `axios` along with `zod` schema checks.

Also, note that similar mistakes or mistakes could happen while using web storage (e.g. `localStorage`)

Validate HTTP API Response with zod, fetch and axios

use zod as an HTTP response validation tool along with fetch and axios in order to make sure that the response has expected data structure

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