The workflow contract pinned the focused path by literal: the job name
`Test (changed packages)`, the unsharded
`list "$TEST_BASE_REF" "$TEST_HEAD_REF"` call, and a single
`go test -timeout=15m` line standing in for internal/app's package-level
headroom. Sharding the job changed all three literals, so `Test (workflow
and release contracts)` failed on this branch even though every shard
selection test passed.
Each invariant the contract guarded still holds, so the assertions are
updated to the new shape rather than relaxed:
- the focused job must still exist, now as the matrix job, named the way
the contract already names `Test (race: ${{ matrix.shard }})`;
- package selection must still derive from the authoritative synthetic
merge base/head, now with an explicit shard argument, so pointing it at
any other ref still fails the contract;
- internal/app's headroom is asserted through the process-isolating
helper and the per-shard budgets, mirroring the assertions already
applied to test-race. That is stronger than the old single -timeout: it
pins the mechanism that keeps the suite inside its budget rather than
the number alone. release-scripts membership is asserted too, because
its dedicated job only runs at full-suite or release-sensitive scope,
so losing it here would silently stop testing test/scripts changes.
The shard comparisons in the focused job are quoted so that job reads
verbatim like test-race's.
Ablating the implementation one change at a time turns the contract red
in all five cases: removing the app helper call, dropping release-scripts
from the matrix, selecting from HEAD~1, collapsing the matrix back to a
single unsharded job, and dropping the cli/smoke timeout budget.