DevOps

Upgrade your Test Suite with fn-monitor

Modern JavaScript testing focuses heavily on testing public outputs and user behavior rather than chasing line-by-line or branch-by-branch coverage.…

Fake timers and await are fighting in your Vitest test

You mock the clock, advance it, and assert. The assertion runs before the code under test has finished. async function poll () { await new Promise (…

Migrating from Jest to Vitest 4: A Complete 2026 Guide

Last month I overhauled the test pipeline for a side project and switched from Jest to Vitest. The reason was straightforward: maintaining Jest in a…

The Unexpected optimization in ESLint vs Vitest: A Head-to-Head

In a 2024 benchmark of 10,000+ line TypeScript codebases, Vitest outperformed ESLint ’s native rule execution by 47% in cold-start lint speed when c…