Router Act Testing Use this skill when writing or modifying tests that involve prefetch requests, client router navigations, or the segment cache. The utility from lets you assert on prefetch and navigation responses in an end-to-end way without coupling to the exact number of requests or the protocol details. This is why most client router-related tests use this pattern. When NOT to Use Don't bother with if you don't need to instrument the network responses — either to control their timing or to assert on what's included in them. If all you're doing is waiting for some part of the UI to appe…