jargonFrontend & browser·Testing a user interface
the test ran in Node with a fake DOM and passed, then the feature broke in an actual browser.
jsdom
Also calledDOM simulation
A JavaScript implementation of the DOM used to run component tests without a browser. It is fast and good enough for structure and interaction, and it has no layout engine at all — element sizes are zero, no CSS is applied, and anything measuring geometry cannot work. Scroll behaviour, media queries and visual state are exactly the things it cannot tell you about.