Skip to the editor
JSGroundwork
JSGroundwork handwritten · web dev
←Back to Testing

Ready to read

JSJavaScript⑂Git◎Interview prepΣDSA in JSSDSystem Design
More topics15›
</>HTML{ }CSS⚛ReactNNext.jsNeNest.jsTSTypeScriptNoNode.js🐳DockerDBSQL & Databases✓Testing🔒Web Security☁Cloud & DevOps◈GraphQL◆Redis☸Kubernetes
☰‹›
Description
All topics›JavaScript›Testing

Inject the clock instead of calling Date.now directly

advancedlayer A9 · Testing3 tests

Write isExpired(expiresAt, now = Date.now) — returns whether expiresAt (a timestamp) has already passed. now defaults to the real clock, but a caller (like a test) can pass a fake one.

Stuck?

All exercisesPlayground
1234567891011121314
loading the editor…

Nothing yet — hit Run and whatever you log shows up here.

Submit to see how you did.

⌘/Ctrl + Enter run⌘/Ctrl + S save⌘/Ctrl + / comment⌘/Ctrl + F find/replace⌘/Ctrl + D select next matchAlt + click multi-cursorTab indent · ⇧Tab outdentEsc leave fullscreen