[E2E] Devstack: Layer 2 (service shims)

[sadiq1971]

Context

Layer 2 provides concrete implementations of each stack interface. Each shim wraps a real service client (go-ethereum, HTTP, database/sql) and satisfies the interface defined in Layer 1. No mocks — shims talk to real services running in Docker.

Files to Create

All files in tests/e2e/devstack/shim/, all with //go:build e2e.

anvil.go

Implements stack.Anvil. Uses go-ethereum/ethclient.

• Constructor: NewAnvil(manifest *stack.ServiceManifest) (stack.Anvil, error)
• Dials manifest.AnvilRPC via ethclient.Dial.
• Loads ABIs from embedded Foundry artifact JSON using //go:embed:
  • contracts/ethereum-wayfinder/out/PromptToken.sol/PromptToken.json
  • contracts/ethereum-wayfinder/out/CantonBridge.sol/CantonBridge.json
• ERC20Balance: packs balanceOf(owner) calldata, calls client.CallContract, unpacks result.
• ApproveAndDeposit:
  1. Signs and sends approve(bridgeAddr, amount) on the token contract.
  2. Signs and sends deposit(amount, partyID) on the bridge contract.
  3. Returns the deposit tx hash.

canton.go

Implements stack.Canton. Simple health-check wrapper.

• Constructor: NewCanton(manifest *stack.ServiceManifest) stack.Canton
• IsHealthy: HTTP GET manifest.CantonHTTP + "/v2/version" — returns true on 200.

apiserver.go

Implements stack.APIServer. HTTP client.

• Constructor: NewAPIServer(manifest *stack.ServiceManifest) stack.APIServer
• Register: POST /register with {evm_address, signature, message} JSON body.
• GetBalance: JSON-RPC eth_call to /eth — calls balanceOf(owner) on the token contract.
• Transfer: JSON-RPC eth_sendTransaction to /eth.
• Health: GET /health — returns nil on 200.

relayer.go

Implements stack.Relayer. HTTP client.

• Constructor: NewRelayer(manifest *stack.ServiceManifest) stack.Relayer
• Health: GET /health.
• IsReady: GET /ready — returns true on 200.

indexer.go

Implements stack.Indexer. HTTP client with a generic helper.

• Constructor: NewIndexer(manifest *stack.ServiceManifest) stack.Indexer
• All methods use a shared getJSON[T](client, url) generic helper that GETs, checks status, and decodes.
• Endpoints follow the pattern /indexer/v1/admin/... (see docs/E2E_TEST_ARCHITECTURE.md §5 for full URL list).

postgres.go

Implements stack.Postgres. Uses database/sql with lib/pq driver.

• Constructor: NewPostgres(manifest *stack.ServiceManifest) (stack.Postgres, error)
• WhitelistAddress: INSERT INTO whitelist (evm_address) VALUES ($1) ON CONFLICT DO NOTHING
• GetUserByEVMAddress: SELECT evm_address, canton_party_id, fingerprint FROM users WHERE evm_address = $1; returns nil, nil for no-rows.

Acceptance Criteria

• go build ./tests/e2e/devstack/shim/... compiles cleanly with -tags e2e.
• Each shim struct satisfies its corresponding stack interface (compiler-enforced via var _ stack.Anvil = (*anvilShim)(nil) assertions).

Dependencies

• Issue [E2E] Devstack: Layer 1 (interfaces + types) + compose file scaffold #178 ([E2E] Devstack: Layer 1) — imports interfaces and types.

Notes

• Do not use testcontainers-go here. Shims connect to services already running in Docker.
• The go:embed path for ABI files must be relative to the package; use a symlink or path alias if needed.
• ApproveAndDeposit should use bind.NewKeyedTransactor pattern consistent with the rest of the codebase.

Size

M (1–2 days)

[sadiq1971]

Depends on: #178