Fake Clocks, Real Guarantees: Inside Go's synctest

The first time I reached for testing/synctest , I assumed it was a sleep helper with better manners. The public API is small enough to support that assumption: synctest . Test ( t , func ( t * testing . T ) { ... }) synctest . Wait () synctest . Sleep ( d ) // new in Go 1.27 Three functions, one obvious guess: fake time, wrapped in test scaffolding. That guess is wrong. It isn&rsquo;t a sleep…