router-act

What problem does it solve?

End-to-end testing of Next.js router interactions becomes deterministic by controlling the timing and responses of router requests (such as prefetches) and by asserting on outcomes.

Core Features & Use Cases

• Act API intercepts router requests (prefetches, navigations) and buffers responses until the test scope ends, enabling deterministic assertions.
• LinkAccordion pattern gates prefetching by toggling link visibility inside an act scope, reducing flakiness.
• Fake clocks and fixtures simulate time-based scenarios, such as segment-cache staleness and navigation timing.
• Use cases include validating prefetch timing, navigation flows, and segment-cache behavior in Next.js apps.

Quick Start

Wrap your test scope with act to deterministically control router requests and responses.