93 articles

#web

All articles tagged with #web.

Project: tests that run on every push

A test suite that only runs on your laptop is a suggestion. Wire Vitest into GitHub Actions so every push and pull request runs it automatically.

Sep 11, 20265 min

Web Dev

Testing React components

Test what a user can see and click, not internal state or class names. Build a live save-link form, then test it with Testing Library like a real user.

Sep 11, 20265 min

Web Dev

Code coverage and the lies it tells

100% coverage means every line ran during the suite. It says nothing about whether the right values were checked. A real bug that coverage missed.

Sep 10, 20265 min

Web Dev

Test databases, fixtures and isolation

Shared test databases cause the flakiest failures in any suite. See why Linkstash defaults to an in-memory database, and how fixtures set up test data.

Sep 10, 20265 min

Web Dev

Integration-testing Linkstash

Unit tests check one function. Integration tests check the whole request through routing, auth, and validation. Real supertest tests against a real API.

Sep 9, 20264 min

Web Dev

Testing async code without flakes

A test that passes locally and fails randomly in CI is almost always a missing await. Learn the pattern, fake timers, and why Express 5 changed the game.

Sep 9, 20264 min

Web Dev

Mocks, stubs and fakes

Replace the database, the email API, or a slow dependency with something you control. Three techniques, what they're each for, and where they go wrong.

Sep 8, 20264 min

Web Dev

Edge cases and the bugs you would have shipped

The bugs that reach production almost never live in the happy path. Two real tests, from a real code review, show what actually catching them looks like.

Sep 8, 20265 min

Web Dev

Arrange, act, assert: the shape of a good test

Every clear test follows the same three-part shape. Learn to spot it, write it on purpose, and see why messy tests almost always skip a step.

Sep 7, 20265 min

Web Dev

TDD: red, green, refactor

Write the test before the code that passes it. A live walkthrough of the red-green-refactor loop, building a slugify function from nothing.

Sep 7, 20265 min

Web Dev

Why write tests

Tests don't prove your code works. They're what lets you change it six months from now without breaking something you can't see happen.

Sep 6, 20265 min

Web Dev

Your first unit test with Vitest

Install Vitest, write one real assertion, and see exactly what expect() checks under the hood before you ever run npx vitest for real.

Sep 6, 20265 min

Web Dev

Project: the Linkstash API end to end

The complete Linkstash architecture in one diagram: every route and decision from this series, tied together and ready for you to build your own version.

Sep 5, 20266 min

Web Dev

Realtime with WebSockets

Why request/response can't push updates to a client, how the WebSocket handshake upgrades an HTTP connection, and where realtime would sit next to Linkstash.

Sep 5, 20265 min

Web Dev

Pagination, filtering and sorting

The intParam helper that stops a negative limit from becoming SQLite's 'no limit at all', plus how Linkstash filters with LIKE and sorts newest first.

Sep 4, 20266 min

Web Dev

User accounts and password hashing done right

Why registerUser inserts first and catches the UNIQUE violation instead of checking first, and why verifyUser hashes a dummy password on every failed login.

Sep 4, 20267 min

Web Dev

Authentication: sessions vs JWT

How Linkstash's opaque session tokens actually work end to end, and the real tradeoff against JWTs: revocability versus a database lookup on every request.

Sep 3, 20266 min

Web Dev

Validating input before it ruins your day

Use Zod's safeParse to reject bad input at the boundary before it reaches your database, with the exact credentials and newLink schemas from Linkstash.

Sep 3, 20266 min

Web Dev

Connecting a database

Wire better-sqlite3 into Express, understand prepared statements as the fix for SQL injection, and why WAL mode is meaningless on an in-memory database.

Sep 2, 20268 min

Web Dev

Error handling and the async trap

How Express 5's four-argument error middleware works, why route order matters for the 404 catch-all, and the async trap Express 4 developers had to work around.

Sep 2, 20266 min

Web Dev

Middleware: the chain every request walks

What middleware actually is in Express, how the (req, res, next) signature works, and the exact bug you get when a middleware forgets to call next.

Sep 1, 20266 min

Web Dev

Designing a REST API that ages well

REST conventions that actually matter: resource-shaped URLs, HTTP verbs over action names, and status codes that tell the truth, with Linkstash's real routes.

Sep 1, 20265 min

Web Dev

Express 5: your first routes

Install Express 5.2, write your first routes with async/await, and see why Express 5 forwards rejected promises to error handling automatically.

Aug 31, 20266 min

Web Dev

Route params, query strings and bodies

The three places a request carries data in Express: :id route params, ?limit= query strings, and JSON bodies, with real Linkstash routes for each.

Aug 31, 20266 min

Web Dev

Your first Node server, no framework

Build an HTTP server with nothing but Node's built-in http module, then see exactly which parts of that work Express will do for you.

Aug 30, 20266 min

Web Dev

What a backend actually does

Why a browser can't talk to a database directly, what a backend is responsible for, and the API contract you'll build across this whole series.

Aug 30, 20265 min

HTTP: the request and response contract

The anatomy of an HTTP request and response: methods, headers, bodies, and status codes. Inspect real request/response pairs interactively.

Aug 26, 20265 min

Web Dev

SQL Project: Design and Query a Database

Put it together: design a small library database with SQL, create the tables, add data, and answer real questions with joins and aggregates. Fully runnable.

Jul 25, 202611 min

Web Dev

SQL Window Functions, Explained Simply

Window functions in SQL without the headache: OVER, PARTITION BY, ROW_NUMBER, RANK, and running totals. Keep every row while you rank and total, live.

Jul 25, 20269 min

Web Dev

SQL Indexes and Query Performance

Make SQL queries fast: what an index is, when to add one with CREATE INDEX, reading EXPLAIN QUERY PLAN, and the trade-offs, explained simply, with examples.

Jul 24, 20268 min

Web Dev

Database Relationships and Foreign Keys

Model relationships in SQL: one-to-many and many-to-many, foreign keys, and how the orders/customers/products tables connect, with a diagram and live queries.

Jul 24, 20269 min

Web Dev

Creating Tables and Schema in SQL

Design tables with SQL: CREATE TABLE, column data types, PRIMARY KEY, NOT NULL, DEFAULT, and UNIQUE constraints. Build and query a table live in your browser.

Jul 23, 202610 min

Web Dev

SQL INSERT, UPDATE and DELETE

Change data in SQL: INSERT new rows, UPDATE existing ones, and DELETE safely, plus why a missing WHERE is dangerous. With live, runnable examples.

Jul 23, 20268 min

Web Dev

SQL Joins: INNER, LEFT and How They Work

Combine tables in SQL with joins: INNER JOIN, LEFT JOIN, join keys, and joining three tables, explained with a diagram and live, runnable queries.

Jul 22, 20268 min

Web Dev

SQL Subqueries and Nested Queries

Use a query inside a query: SQL subqueries in WHERE with IN and EXISTS, scalar subqueries, and subqueries in FROM, with live, runnable examples.

Jul 22, 20269 min

Web Dev

SQL Aggregate Functions: COUNT, SUM, AVG

Summarize data in SQL with aggregate functions (COUNT, SUM, AVG, MIN, MAX) and understand how they collapse many rows into one, with live queries to run.

Jul 21, 20267 min

Web Dev

SQL GROUP BY and HAVING, Explained

Group rows and summarize per group with SQL GROUP BY, then filter groups with HAVING, and learn why HAVING isn't WHERE. With live, runnable queries.

Jul 21, 20268 min

Web Dev

SQL ORDER BY, LIMIT and DISTINCT

Sort and trim SQL results: ORDER BY ascending/descending, sorting by multiple columns, LIMIT and OFFSET for paging, with live runnable queries.

Jul 20, 20268 min

Web Dev

SQL WHERE: Filtering Rows with Conditions

Filter rows in SQL with WHERE: comparison and logical operators, BETWEEN, IN, LIKE, and IS NULL, with live, runnable queries in your browser.

Jul 20, 20268 min

Web Dev

SQL SELECT Basics: Querying Your Data

The SQL SELECT statement, explained: choose columns, use SELECT *, rename with AS, and remove duplicates with DISTINCT, runnable live in your browser.

Jul 19, 20269 min

Web Dev

Why Learn SQL in 2026 (and What a Database Is)

What SQL and relational databases are, why every app needs one, and your first live query, runnable in your browser against a real database.

Jul 19, 20267 min

Web Dev

Migrate a JavaScript Project to TypeScript

A practical capstone: convert a small JavaScript project to TypeScript step by step, covering tsconfig, types, and fixing errors, hands-on.

Jul 18, 20269 min

Web Dev

TypeScript Utility Types You'll Actually Use

The TypeScript utility types worth knowing: Partial, Pick, Omit, Record, and Required, and what each does, with runnable examples.

Jul 18, 20268 min

Web Dev

TypeScript Generics, Finally Explained

Generics in TypeScript without the headache: reusable, type-safe functions and types, from <T> to constraints, with examples.

Jul 17, 20267 min

Web Dev

Using TypeScript with React, Practically

Type React the practical way: props, state, events, and children, the patterns you'll actually use, with a live TypeScript + React editor.

Jul 17, 20267 min

Web Dev

TypeScript Arrays, Objects and Tuples

Type collections in TypeScript: arrays, object types, tuples, and the differences that matter, with clear, runnable examples.

Jul 16, 20268 min

Web Dev

TypeScript Union Types and Narrowing

Model 'one of several' with union types and safely narrow them with typeof, in, and discriminated unions, with live examples.

Jul 16, 20268 min

Web Dev

TypeScript Functions and Type Inference

Type function parameters and return values in TypeScript, and let inference do the work, with practical, runnable examples.

Jul 15, 20268 min

Web Dev

TypeScript Interfaces vs Type Aliases

Describe object shapes in TypeScript with interfaces and type aliases: when to use which, plus optional and readonly fields, with examples.

Jul 15, 20269 min

Web Dev

TypeScript Basic Types, Explained

The core TypeScript types (string, number, boolean, arrays, any vs unknown), plus type annotations vs inference, with live runnable code.

Jul 14, 20268 min

Web Dev

Why TypeScript? Catch Bugs Before You Run

What TypeScript is, the bugs it catches before runtime, and why it took over, with live, type-checked examples from the very start.

Jul 14, 20267 min

Web Dev

React Composition Patterns That Scale

Write React that stays clean: composition over props soup, the children prop, and lifting state up. Practical patterns with examples.

Jul 13, 20268 min

Web Dev

React Project: Build a Todo App with Hooks

Put it together: build a working React todo app with state, events, lists, and forms, fully editable live in your browser.

Jul 13, 20269 min

Web Dev

React Context: Share State Without Prop Drilling

Use React Context to share state across components without prop drilling. When to reach for it, when not to, and live code to try it out.

Jul 12, 20267 min

Web Dev

React Custom Hooks: Reuse Logic Cleanly

Extract and reuse logic with custom React hooks: the rules of hooks and a practical useLocalStorage example, runnable live.

Jul 12, 20268 min

Web Dev

Fetching Data in React with useEffect and fetch

Load data from an API in React: fetch in useEffect, loading and error states, and avoiding common bugs, with a live example.

Jul 11, 20268 min

Web Dev

React useEffect: Side Effects, Explained

Understand the useEffect hook: when effects run, the dependency array, and cleanup, without the usual confusion, with live code.

Jul 11, 20269 min

Web Dev

Conditional Rendering in React, Explained

Show and hide UI in React: ternaries, the && operator, early returns, and clean patterns for conditional rendering, with a live editor.

Jul 10, 20266 min

Web Dev

React Forms and Controlled Components

Build forms in React the right way: controlled inputs, handling change, simple validation, and submitting, with runnable examples.

Jul 10, 20268 min

Web Dev

Handling Events in React, Explained

Respond to clicks, input and form events in React: event handlers, the synthetic event, and passing arguments, with runnable live examples.

Jul 9, 20268 min

Web Dev

React Lists and Keys: Rendering Arrays

Render arrays in React with map, and why keys matter for correct, fast updates, with clear, runnable live examples.

Jul 9, 20267 min

Web Dev

React Components and Props, Explained

Build reusable React components and pass data with props. Composition, children, and default values, with runnable live examples.

Jul 8, 20269 min

Web Dev

React State with the useState Hook

Make React components interactive with useState: state vs props, updating state correctly, and re-renders, with a live counter example.

Jul 8, 20268 min

Web Dev

React JSX, Explained: HTML in Your JavaScript

How JSX works in React: expressions in curly braces, attributes, fragments, and the rules that trip up beginners, with a live editor.

Jul 7, 20267 min

Web Dev

Why React? Components and the UI Mental Model

What React is, the component mental model, and why it took over UI development, with a live React component you edit in the first minute.

Jul 7, 20268 min

Web Dev

CSS Project: Build a Responsive Landing Page

Put HTML and CSS together: build a clean, responsive landing page from scratch, covering layout, type, and polish, live in your browser.

Jul 6, 202613 min

Web Dev

Build a Responsive Card Layout with CSS Grid

A hands-on CSS project: build a responsive card grid that reflows on any screen using Grid and modern CSS, fully editable in your browser.

Jul 6, 202610 min

Web Dev

CSS Transitions and Animations, Explained

Add motion with CSS: transitions, transforms, and keyframe animations done tastefully and accessibly, with a live, editable preview you can edit.

Jul 5, 20267 min

Web Dev

Modern CSS in 2026: :has(), Container Queries

The modern CSS worth knowing now: custom properties, :has(), container queries, and nesting, with practical examples you can edit live.

Jul 5, 20269 min

Web Dev

CSS Positioning and z-index, Demystified

Understand CSS position (static, relative, absolute, fixed, sticky) and how z-index stacking really works, with editable examples.

Jul 4, 202610 min

Web Dev

Responsive Web Design with CSS Media Queries

Make pages work on any screen: mobile-first CSS, media queries, fluid units, and responsive images, with a live, editable preview.

Jul 4, 20268 min

Web Dev

CSS Flexbox: One-Dimensional Layout, Explained

Master CSS Flexbox: main vs cross axis, justify-content, align-items, and flex-wrap, with an interactive playground to see it move.

Jul 3, 20269 min

Web Dev

CSS Grid: Two-Dimensional Layout, Explained

Build real layouts with CSS Grid: columns, rows, gaps, and placement, with an interactive grid playground to experiment live.

Jul 3, 20268 min

Web Dev

CSS Colors, Units and Typography Basics

Style text and color in CSS: hex/rgb/hsl, rem vs px vs %, web fonts, and readable typography, with a live, editable preview.

Jul 2, 20269 min

Web Dev

CSS Selectors and the Box Model, Explained

How CSS selectors target elements and how the box model (margin, border, padding, content) controls size, with editable live examples.

Jul 2, 20269 min

Web Dev

HTML Forms and Inputs: A Practical Guide

Build accessible HTML forms: inputs, labels, selects, checkboxes, validation attributes, and the submit flow, with a live preview.

Jul 1, 20269 min

Web Dev

HTML Structure and Semantic Tags, Explained

Build a real web page with semantic HTML: headings, lists, links, images, and landmark tags like header, main and article, with a live preview.

Jul 1, 20269 min

Web Dev

JavaScript async/await and the fetch API

Write clean asynchronous JavaScript with async/await and fetch real data from an API, with live, runnable examples.

Jun 30, 20267 min

Web Dev

JavaScript Project: Build an Interactive Quiz App

Put it all together: build a small interactive quiz app in vanilla JavaScript, using DOM, events, and state, runnable in your browser.

Jun 30, 202610 min

Web Dev

JavaScript Callbacks and Promises, Explained

Understand asynchronous JavaScript: callbacks, the problem they cause, and how Promises fix it, with live, runnable examples to try.

Jun 29, 20268 min

Web Dev

JavaScript Events: Clicks, Input and Listeners

Respond to users with JavaScript events: addEventListener, the event object, clicks and input. Build interactivity, live in your browser.

Jun 29, 20268 min

Web Dev

JavaScript Objects: Properties, Methods and this

Model real things with JavaScript objects: properties, methods, dot vs bracket access, and a first look at this, with live code.

Jun 28, 20269 min

Web Dev

The JavaScript DOM: Select and Change the Page

Use JavaScript to read and change a web page: select elements, edit text and styles, and create nodes, all with a live preview.

Jun 28, 20268 min

Web Dev

JavaScript map, filter and reduce, Explained

Transform arrays the modern way with map, filter and reduce. Clear examples of each, runnable live in your browser.

Jun 27, 20269 min

Web Dev

JavaScript Arrays: Create, Access and Change Lists

Store lists in JavaScript arrays: indexing, adding and removing items, and the most useful array methods, runnable in your browser.

Jun 27, 20268 min

Web Dev

JavaScript Arrow Functions and Scope, Explained

Arrow functions vs regular functions, plus block scope and closures in plain English, with live, runnable JavaScript examples.

Jun 26, 20269 min

Web Dev

JavaScript Functions: Parameters and Return Values

Define and call JavaScript functions: parameters, return values, default parameters, and why functions are the heart of the language.

Jun 26, 20266 min

Web Dev

JavaScript Loops: for, while and for...of

Repeat work in JavaScript with for, while, for...of and for...in loops. When to use each, with live runnable examples.

Jun 25, 20268 min

Web Dev

JavaScript Operators and if/else Conditionals

Arithmetic, comparison and logical operators, plus if/else and the ternary. Make decisions in JavaScript, with live runnable code you can edit.

Jun 25, 20268 min

Web Dev

JavaScript Data Types: Numbers, Strings, Booleans

The core JavaScript data types (number, string, boolean, null, undefined) and how typeof works, explained with live runnable examples.

Jun 24, 20267 min

Web Dev

JavaScript Strings and Template Literals, Explained

Work with text in JavaScript: string methods, concatenation, and template literals for clean interpolation, with runnable examples throughout.

Jun 24, 20268 min

Web Dev

JavaScript Variables: let, const and var Explained

How to store data in JavaScript with let and const (and why to skip var), plus block scope basics, runnable live in your browser.

Jun 23, 20268 min

Web Dev

Why Learn JavaScript in 2026 (and Where It Runs)

What JavaScript is, where it runs (browser and server), and why it's the language of the web, with live code you run in the very first minute.

Jun 23, 20267 min