JavaScript

JavaScript import/require module testing do’s and don’ts with Jest The example repository is available at github.com/HugoDF/mock-spy-module-import. This post goes through how to achieve different types of module mocking scenarios with Jest. From simple Import interc ...

When debugging or writing units tests with Jest it can be useful to specify a single file or test to run or to exclude a specific failing test for the Jest run. This post goes how to skip and exclude a single test, a whole Jest test suite and a whole Jest test file using the CLI ...

Detecting control-click, command-click, meta-click, alt-click and shift-click in JavaScript without listening to keydown events is straightforward. The naive approach is to bind aggressively to key events (keydown, keypress, keyup) and to maintain state of what is currently press ...

micro-analytics-events - A Node.js microservice to record analytics events to SQLite3 with Zeit’s “micro” In order to finally switch off Google Analytics, I need to replace my goal conversion tracking somehow. I’ve got pageview data using Simple Analytic ...

By default Jest runs tests in parallel with a “a worker pool of child processes that run tests” (Jest CLI docs). As per the Jest documentation, running tests in sequence (serially), can be helpful for debugging purposes and for test run performance reasons. ...

How does one identify whether a JavaScript file is being run directly (node file.js) or it’s being import/require-d (require('./file') in another JS file). In Python the pattern leverages the __main__ property in modules like so: if __name__ == '__main__': # do some ...

With ES6, more developers should be leveraging built-ins than are using lodash functions. Here is an ES6 implementation of lodash/underscore’s uniq: const dedupe = list => [...new Set(list)]; This post goes through the how and why this works. It explores Sets, iterabl ...

Add diagrams to your JAMStack (Jekyll/Hugo/Gatsby) blog with Mermaid JS The following post will go through how to integrate Mermaid JS, a “simple markdown-like language for generating charts”. It will initially go through the benefits of MermaidJS, followed by a gen ...

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 ...