test(reservations): M2 test-coverage backfill (7 of 8 items)

[piotr-roslaniec]

Summary

Implements implementation-plan.md Milestone 2's test-coverage backfill:
7 of the 8 listed items. Stacked on m1/reservation-multisigner-integration-test
(#4279), tip
cb4334627.

The 8th item (ValidateReservationAnchorProposal/
ValidateReservationReanchorProposal tests) is explicitly deferred - it
needs go-ethereum simulated-backend test infrastructure that doesn't
exist anywhere in pkg/chain/ethereum today, well beyond the plan's
0.5-day estimate. See docs/spec/reservations/m1-keep-core-readiness/01-gap-analysis.md's
new Minor row for the full finding.

Change

pkg/tbtc/reservation_test.go

• TestAssembleReservationAnchorTransaction: happy-path output shape
  (1-in-1-out, deposit value minus fee, P2WPKH to the target wallet). Also
  doubles as the golden reference for pkg/tbtcpg's dedup test below.
• TestAssembleReservationReanchorTransaction: same shape assertion for
  the re-anchor sibling.

pkg/chain/ethereum/tbtc_test.go

• TestConvertReservationParametersFromAbiType: full 10-tuple field
  mapping, every field a distinct non-zero value so a swapped or dropped
  field can't hide behind a shared zero default.
• TestConvertReservationFromAbiType_DropsCumulativeReanchorFee: pins the
  intentional CumulativeReanchorFee omission and verifies every other
  field maps correctly around it.

pkg/tbtcpg/reservation_acceptance_test.go

• TestReservationAcceptanceTask_BoundaryChecks: 6-case table (at-limit
  accepts / one-over rejects) for MaxReservationsPerWallet,
  ReservationMinAmount, and ReservationMaxTotalAmount -
  TestReservationAcceptanceTask_BoundedLookback only ever used these
  fields as fixture data, never at the actual boundary.
• TestReservationAcceptanceTask_ReservationParametersFetchedLive: runs
  the same task twice against the same deposit, mutating
  ReservationMinAmount between calls - proves ReservationParameters()
  is fetched live per call, not cached on the task.

pkg/tbtcpg/reservation_anchor_dedup_test.go (new file, package tbtcpg - internal, not tbtcpg_test - to reach the unexported function)

• TestBuildReservationAnchorTransaction_MatchesPkgTbtcGoldenOutput:
  buildReservationAnchorTransaction (pkg/tbtcpg) and
  assembleReservationAnchorTransaction (pkg/tbtc) are independently
  maintained copies of the same logic, both unexported in different
  packages - Go's visibility rules make a single test calling both
  impossible without a production-code change. This test and pkg/tbtc's
  TestAssembleReservationAnchorTransaction instead pin the identical
  golden input/output values (deposit 100000, fee 1500, output 98500) in
  each package, catching either copy drifting from the other. The
  underlying duplication itself is unresolved - extracting a shared
  exported helper is the real fix, deferred as a larger (L, 1-2 day)
  change per decision this session.

Testing

• go test ./pkg/tbtc/... ./pkg/tbtcpg/... ./pkg/chain/ethereum/...:
  519/519 pass.
• go build ./... && go test ./...: full repo, 49 packages, zero FAIL.
• gofmt -l / go vet: clean on all 4 changed/new files.

Not in this PR

• ValidateReservationAnchorProposal/ValidateReservationReanchorProposal
  tests - deferred, documented in the gap-analysis doc.
• Extracting a shared buildReservationAnchorTransaction/
  assembleReservationAnchorTransaction helper to eliminate the
  duplication for good - the golden-value tests catch drift but don't fix
  the root duplication.

[coderabbitai]

Important

Draft PR not reviewed

Draft PRs are not automatically reviewed by default.

• Trigger a manual review

To automatically review draft PRs, update your CodeRabbit configuration:

reviews:
  auto_review:
    drafts: true

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}