jest-advanced

Installation
SKILL.md

Jest Advanced

Master advanced Jest features including custom matchers, parameterized tests with test.each, coverage configuration, and performance optimization. This skill covers sophisticated testing techniques for complex scenarios and large test suites.

Custom Matchers

Creating Custom Matchers

// matchers/toBeWithinRange.js
export function toBeWithinRange(received, floor, ceiling) {
  const pass = received >= floor && received <= ceiling;
  if (pass) {
    return {
      message: () =>
        `expected ${received} not to be within range ${floor} - ${ceiling}`,
      pass: true
    };
  } else {
Related skills
Installs
25
GitHub Stars
150
First Seen
Jan 22, 2026