JavaScript

How to use Yarn Workspaces to manage applications/coding examples. Lerna isn’t required when you don’t need the git diffing and versioning facilites. What’s more Yarn Workspaces are a great lightweight tool to get up and running faster for simple Node.js monor ...

Hugo “The world’s fastest framework for building websites” is a great option for JAMStack (JavaScript, APIs, prebuild Markup) sites. Lunr.js is “A bit like Solr, but much smaller and not as bright”, it’s a pure JavaScript implementation of a Solr-lik ...

JavaScript (JS) is a lightweight, interpreted, or just-in-time compiled programming language with first-class functions. MDN Web Docs - JavaScript Detailed in this post are common JavaScript data type checks, pitfalls and idiomatic workarounds. ...

In computer science, test coverage is a measure used to describe the degree to which the source code of a program is executed when a particular test suite runs. Code coverage - Wikipedia Code coverage is usually used as a quality metric for software eg. “Our code has to have 80 ...

An example Netlify Lambda to fetch all “newsletter” posts from Pocket. Pocket is an application and web service for managing a reading list of articles from the Internet. It’s quite widely used and tightly integrated into the Firefox browser. I find that I use it extensiv ...

There are situations where new Date() or Date.now is used in application code. That code needs to be tested, and it’s always a struggle to remember how to mock/stub or spy on Date.now/new Date with Jest. This post goes through multiple approaches to mocking, stubbing and spying o ...

A case-study on where recursion can be useful for enterprise Node.js applications and how to avoid its common pitfalls like RangeError: Maximum call stack size exceeded. The full repository for this post is on GitHub: github.com/HugoDF/mongo-query-clause-modification We’ll ...

When asked to handle data in a request body, developers who have used Express (the “Fast, unopinionated, minimalist web framework for Node.js”) before, reach for the body-parser library. What they might not know is that body-parser is a dependency of Express and its main JSON par ...

The ES2015 or ES6 specification introduced class to JavaScript. Libraries like React went from React.createClass to class MyComponent extends React.Component, ie went from rolling their own constructor to leveraging a language built-in to convey the programmer’s intent. For a Nod ...

With Jest it’s possible to assert of single or specific arguments/parameters of a mock function call with .toHaveBeenCalled/.toBeCalled and expect.anything(). The full example repository is at github.com/HugoDF/jest-specific-argument-assert, more specifically lines 17-66 ...