The module doc of contracts/test-utils/concurrency/backend.ts carries the reasoning behind the dry replay harness: why a conflict is reproduced by building two calls on one snapshot, why classification replays against the build state, and how the live backend maps onto the same contract. It is good material in the wrong place; a reader of the harness API has to scroll past it, and a reader looking for the design has no reason to open that file.
Move it to docs/design/ as a concurrency-harness design doc and leave backend.ts with a one-paragraph summary and a link.
Raised in #743 review: #743 (comment)
The module doc of
contracts/test-utils/concurrency/backend.tscarries the reasoning behind the dry replay harness: why a conflict is reproduced by building two calls on one snapshot, why classification replays against the build state, and how the live backend maps onto the same contract. It is good material in the wrong place; a reader of the harness API has to scroll past it, and a reader looking for the design has no reason to open that file.Move it to
docs/design/as a concurrency-harness design doc and leavebackend.tswith a one-paragraph summary and a link.Raised in #743 review: #743 (comment)