Testing

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Running tests

cd nu_pos_sync_protocol
npx vitest run

cd nu_pos_hub
npx vitest run

cd nu_pos_react
npx vitest run

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Single test file

cd nu_pos_react && npx vitest run src/state/machines/__tests__/syncMachine.test.ts
cd nu_pos_hub && npx vitest run src/handlers/__tests__/orderHandler.test.ts

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Watch mode

cd nu_pos_react && npm test
cd nu_pos_hub && npm test

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Test architecture

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Protocol tests

• Round-trip validation for all terminal and hub message types
• Rejection of malformed messages (missing fields, wrong types)
• parseTerminalMessage(), parseHubMessage(), parseProtocolMessage() helpers

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Hub tests

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Storage layer (41 tests)

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Lease manager (25 tests)

• Acquire: new lease, re-entrant, denied (held by other), force override
• Release: by holder, by non-holder (rejected), with final snapshot
• Heartbeat: renewal, rejected for non-holder
• Tick: expired lease revocation, callback invocation
• Disconnect: grace period extension

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Handlers (14 tests)

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Server (25 tests)

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Upstream (24 tests)

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Frontend tests

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Sync-specific (67 tests)

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Transport infrastructure (31 tests)

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Testing patterns

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Hub: in-memory SQLite

beforeEach(() => {
  db = initDb(":memory:");
  orderStore = createOrderStore(db);
});

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Hub: mock WebSocket

function makeMockWs() {
  return {
    send: vi.fn(),
    readyState: 1,
    OPEN: 1,
  } as unknown as import("ws").WebSocket;
}

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Frontend: module mocking

vi.mock("../sync/outbox", () => ({
  queueOutbound: vi.fn(),
  flushOutbound: vi.fn().mockResolvedValue({ sent: 0, failed: 0 }),
  listOutbound: vi.fn().mockReturnValue([]),
}));

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Frontend: XState actor testing

const actor = createActor(syncMachine);
actor.start();
actor.send({ type: "TRANSPORT_RECONNECTING" });
expect(actor.getSnapshot().value).toBe("reconnecting");

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What’s not tested

• SyncStatusIndicator — Read-only badge, tested visually
• ConflictDialog — Radix UI dialog, tested visually
• SyncOverlay — Toast integration, tested visually
• SyncUIProvider — Simple React context with useState
• RealtimeProvider — Tested indirectly through transport and machine tests