When many of us first learned programming, the natural tendency when writing functions was often sequential validation: check condition A, if true check condition B, if true check condition C, and then finally perform the core logic or return the result.
This approach might look something like this conceptually:
function processData(data, user, config) { if (data !== null && data !== undefined) { if (user.isAuthorized) { if (config.isEnabled) { // --- Core Logic --- console.
Mastering test automation requires more than just understanding theory; it demands hands-on practice. Finding suitable, reliable “playgrounds” where you can experiment with different scenarios – from basic UI interactions to complex AJAX handling, modern frameworks, API calls, and mobile gestures – is crucial for skill development.
But where can you find these resources? Many live websites aren’t appropriate targets, and building complex test apps yourself takes time away from learning automation techniques.
Ever needed to access a web service running only on your local development machine from a remote server, like a DigitalOcean droplet? Perhaps you want to test a webhook integration hitting your local instance, or demo a local site without deploying it fully. SSH Remote Port Forwarding provides a secure and relatively simple way to achieve this.
This guide walks through setting up a DigitalOcean droplet and configuring your local SSH client to forward ports from the remote droplet back to your local machine.
This post is inspired by experiences writing vdirsyncer and explores a common synchronization challenge. It’s aimed at developers needing to implement synchronization, especially when journal-based approaches aren’t feasible due to API limitations.
Synchronizing data between two locations (e.g., a local client and a cloud service, or two cloud services) is a common problem. How do you ensure that additions, deletions, and modifications on one side are correctly reflected on the other, especially when you can’t rely on a central transaction log or journal?
SSH (Secure Shell) is renowned for providing secure command-line access to remote servers. However, its capabilities extend far beyond simple terminal sessions. One of its most powerful features is port forwarding (also known as SSH tunneling), which allows you to securely tunnel network connections from one machine to another through an encrypted SSH link.
Understanding port forwarding can unlock solutions for various networking challenges, from bypassing firewalls to securely accessing internal services or even exposing local development environments to the internet temporarily.
If you frequently connect to multiple remote servers using SSH, you probably find yourself typing the same usernames, IP addresses, ports, and options repeatedly. Remembering specific key files for different hosts can also be a hassle. Thankfully, the SSH client has a powerful configuration file that can simplify your workflow dramatically.
This guide explores the SSH config file (typically ~/.ssh/config), how to set it up, common use cases, and related security practices like SSH key management and disabling password authentication.
In modern software development, the ability to deploy code frequently and safely is paramount. We often want to merge code into the main branch continuously, even if the features aren’t fully ready for all users. How can we deploy code containing unfinished or experimental features without exposing them prematurely? The answer often lies in Feature Toggles (also known as Feature Flags).
As extensively documented by experts like Martin Fowler, feature toggles are essentially conditional switches in your code that allow you to turn features on or off without deploying new code.
TypeScript offers incredible benefits with its static type system, catching errors at compile time and improving developer productivity. However, TypeScript’s guarantees often end at your application’s boundaries. What happens when data comes in from an external API, a user form, or a configuration file? How can you be sure that runtime data actually matches the TypeScript types you expect?
Enter Zod, a TypeScript-first schema declaration and validation library that bridges this gap beautifully.
Reactive programming with RxJS offers a powerful way to handle asynchronous events and data streams. At the heart of RxJS are Observables, which represent these streams, and Operators, which are functions used to manipulate, transform, and manage the data flowing through them.
Operators are chained together using the pipe() method on an Observable. Each operator takes an Observable as input and returns a new Observable, allowing for complex data flows to be built declaratively.
Connecting your application’s core logic (the domain objects) to a persistent store (like a database) is a fundamental task. However, directly embedding database logic within your domain objects can lead to tight coupling, making your code harder to test, maintain, and evolve. How can we keep these concerns separate?
Enter the Data Mapper pattern. As Martin Fowler describes in “Patterns of Enterprise Application Architecture” (P of EAA, page 165):
A layer of Mappers that moves data between objects and a database while keeping them independent of each other and the mapper itself.
Software development is often about managing complexity and change. As applications grow, how do we add new features without breaking existing ones? How do we ensure our code remains maintainable, flexible, and robust? Two core principles from the SOLID acronym offer powerful guidance: the Open/Closed Principle (OCP) and the Liskov Substitution Principle (LSP).
Let’s dive into what these principles mean, why they matter, and how TypeScript helps us implement them effectively.
In modern application development, especially with layered architectures or microservices, data needs to move between different parts of the system. How do we manage this flow cleanly and efficiently? Enter the Data Transfer Object (DTO).
As noted, a fundamental principle is:
A DTO should just contain data, not business logic. It’s a simple, small thing that should do one task only: carry data between processes or layers.
Let’s unpack what DTOs are, why they are crucial, and how they differ from other related concepts like Entities and Domain Objects.
Writing software that works is one thing; writing software that is easy to understand, maintain, extend, and test is another. As applications grow in complexity, adhering to sound design principles becomes crucial for long-term success and sanity. Two fundamental sets of guidelines stand out: the SOLID principles for object-oriented design and the DRY principle.
Let’s break down these concepts to understand how they help us build better software.
The SOLID Principles Coined by Robert C.
For AI and deep learning tasks, NVIDIA GeForce GPUs are generally considered better than AMD Radeon GPUs. This is primarily due to the following reasons:
CUDA support: NVIDIA GPUs support CUDA, a parallel computing platform and programming model developed by NVIDIA. CUDA is widely used in AI and deep learning frameworks, such as TensorFlow and PyTorch, which makes NVIDIA GPUs more compatible and efficient for these tasks.
cuDNN library: NVIDIA provides the cuDNN library, a GPU-accelerated library for deep neural networks.
A task queue is a mechanism for managing and executing tasks in an ordered and efficient way. In this blog post, we will explore how to write a task queue in SQL. We will use PostgreSQL as our database management system.
1. Design the Task Queue Table To begin, we need to design a table to store our tasks. The table should have the following fields:
id: A unique identifier for the task.
Use ES6 arrow functions: One of the simplest ways to access the correct “this” inside a callback is to use ES6 arrow functions. Arrow functions are essentially anonymous functions that don’t change the value of “this” and always point to the outer lexical scope. This means that you don’t have to worry about using call or apply to bind the function to the object.
Here’s an example:
class Foo {
constructor() {
this.
Animating UI layouts can be a challenging task, especially when the layout changes dynamically based on user interactions. In this blog post, we will explore the FLIP technique, a powerful approach for animating UI layouts that can make the process much easier and more efficient.
What is the FLIP Technique? FLIP stands for First, Last, Invert, Play. It is a technique for animating UI layouts that was introduced by Paul Lewis and Jonathan Neal in 2015.
As a full-stack freelancer developer, you need to be proficient in a wide range of technologies to deliver top-quality projects to your clients. Whether you specialize in web development, mobile development, or other areas, there are certain technologies that you simply cannot afford to ignore. In this article, we’ll explore five key technologies that every full-stack freelancer developer must master to stay competitive in today’s market.
HTML, CSS, and JavaScript HTML, CSS, and JavaScript form the core of front-end web development, and you need to be proficient in all three to create dynamic, responsive, and visually appealing websites.
The traditional financial system is based on fractional reserve banking, where banks hold only a fraction of their depositors’ money in reserve and lend out the rest. This system has been in place for centuries and is the foundation of the modern economy. However, with the advent of Bitcoin, a new type of financial system has emerged that is based on a completely different set of principles. In this article, we will explore the differences between the fractional money system and Bitcoin.
In recent years, blockchain technology has become one of the most popular buzzwords in the world of technology. From finance to healthcare, logistics to agriculture, almost every industry is exploring the potential of blockchain technology. The concept of blockchain has been around for a while, but it was not until the invention of Bitcoin that it gained popularity. Today, blockchain is not just associated with cryptocurrencies but is being hailed as a game-changer in various sectors.
Asynchronous programming is a way of performing tasks on a non-blocking basis, allowing you to write more efficient and responsive code. However, returning the response or result from a function that makes an asynchronous request can be a bit tricky. In this blog post, we will go over how you can return the response or result from a function that makes an asynchronous request.
Use a Promise: One way to return the response or result from a function that makes an asynchronous request is to use a Promise.
API Security Checklist
Use HTTPS: Always use HTTPS to encrypt data in transit between the client and server. This helps prevent man-in-the-middle attacks and protects sensitive data.
Use Strong Authentication: Use strong authentication mechanisms such as OAuth 2.0 or JSON Web Tokens (JWTs) to authenticate users and control access to APIs. Also, avoid using basic authentication, which sends passwords in plaintext.
Limit Access: Limit access to APIs to only those users who need it.
When it comes to event binding with dynamically created elements in TypeScript, we need to understand the different ways elements can be created. There are essentially two ways to create elements dynamically: programmatically, and through data binding.
Programmatically creating an element can be done using the DOM API, which allows us to create, append, and remove elements as needed. For instance, we might create a new button element and append it to an existing div element using the DOM API:
Lets imagine that we need to model different types with common properties.
At first without using intersection types you will have following type definitions.
type Conference = { title: string, description: string, location: string, talks: string[] } type Webinar = { title: string, description: string, invationLink: string, talks: Talk } But it is possible to define a base type and use intersection types to define new types.
type TalkBase = { title: string, description: string, } type Conference = TalkBase & { location: string, talks: string[] } type Webinar = TalkBase & { invationLink: string, talks: Talk }
If you’re a developer, you’ve likely heard of TypeScript. It’s a popular programming language that has been steadily gaining traction in recent years. TypeScript is a superset of JavaScript, meaning it builds on top of JavaScript to add features that make development easier and more efficient. In this article, we’ll take a closer look at TypeScript, exploring its features, benefits, and use cases.
What is TypeScript? TypeScript is an open-source programming language that was first released in 2012.
TypeScript is a popular programming language that brings many benefits to JavaScript developers, including the ability to use union types. Union types are a powerful feature that allows developers to create variables that can hold multiple types of values. In this article, we’ll take a closer look at TypeScript union types, exploring their features, benefits, and use cases.
What are Union Types? A union type is a type that represents a variable that can hold one of several possible types.
As businesses increasingly rely on technology to operate and grow, the demand for skilled developers has skyrocketed. But for small and mid-sized businesses with limited budgets, hiring a full-time, in-house developer may not be feasible. That’s where full-stack freelancer developers come in - they offer the expertise of a professional developer, without the long-term commitment and expense of hiring a full-time employee.
In this article, we’ll explore the benefits of hiring a full-stack freelancer developer for your business, and how they can help you achieve your goals.