JavaScript

Advantages and Disadvantages of Node.js

JavaScript is perhaps the most highly regarded of the different programming languages out there, and in terms of client-side programming languages, there are few tools that are peers to JavaScript. In terms of web development, it is clear that JavaScript has a very important role ...

#javascript #node #testing #deployment

Managing Your Videos With HTML and JavaScript

This article explains how to manage video content with HTML and JavaScript. Video content has become a significant part of Internet use, and it plays a large role in user experience. The ability to effectively include video content in your sites can help you improve user experien ...

#vuejs #javascript

Fix "[Vue warn]: You are using the runtime-only build of Vue"

This post explains how to fix “[Vue warn]: You are using the runtime-only build of Vue where the template compiler is not available. Either pre-compile the templates into render functions, or use the compiler-included build.”. This error happens when using the Vue CLI ...

#jest #testing #javascript #node

Jest set, clear and reset mock/spy/stub implementation

Between test runs we need mocked/spied on imports and functions to be reset so that assertions don’t fail due to stale calls (from a previous test). This is a way to mitigate what little statefulness is in the system. In unit tests of complex systems, it’s not always ...

#jest #testing #javascript #node

Jest .fn() and .spyOn() spy/stub/mock assertion reference

Where other JavaScript testing libraries would lean on a specific stub/spy library like Sinon - Standalone test spies, stubs and mocks for JavaScript. Works with any unit testing framework., Jest comes with stubs, mocks and spies out of the box. This post looks at how to instanti ...

#jest #node #javascript #testing

Jest Array/Object partial match with objectContaining and arrayContaining

It’s possible to do partial matches on Arrays and Objects in Jest using expect.objectContaining and expect.arrayContaining. expect has some powerful matcher methods to do things like the above partial matches. Using Jest at an advanced level means using tools like these to ...

#javascript #jest #node #testing

Jest explicitly or arbitrarily force fail() a test

When testing code with Jest, it can sometimes be useful to fail a test arbitrarily. This post goes through a few scenarios where that might be useful and how to fail a Jest test explicitly/in a forced manner. It also presents more idiomatic Jest patterns that could be used interc ...

#node #javascript #python

How to integrate Python/Ruby/PHP/shell script with Node.js using child_process.spawn or child_process.exec

There are occasions when running a Python/Ruby/PHP shell script from Node.js is necessary. This post looks at best practices around leveraging child_process.spawn and child_process.exec to encapsulate this call in Node.js/JavaScript. The goal here is to have an interoperability l ...

#javascript #jest #node #es6 #testing

Jest Full and Partial Mock/Spy of CommonJS and ES6 Module Imports

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 interce ...

#jest #javascript #node #testing

How to run, ignore or skip Jest tests, suites and files

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 ...

A collection of 104 posts