The Routing-Library Major Nobody Tested — Pinning a Route Table in 15 Tests
Oct 28, 2026
4 min read
Mule’s backend is Go and gets the usual attention: go build, go test, race detector, the works. The frontend — a React admin UI I mostly ignore until it breaks — had exactly zero unit tests. Then Dependabot opened a PR bumping react-router-dom from 6.30.4 to 7.18.4 to fix three security advisories, and I was faced with the classic maintainers’ dilemma: merge a routing-library major version into an untested SPA, or let three GHSAs sit in production.