すでに「有効」になっている複数シート購入を、10月22日の前に残すか外すか決める

import StoreKit
 
enum Access: Equatable {
    case none
    case active(productID: String, ownership: Transaction.OwnershipType, expires: Date?)
}
 
struct EntitlementResolver {
    let proProductIDs: Set<String>
 
    func current() async -> Access {
        var best: Access = .none
        for await result in Transaction.currentEntitlements {
            // 検証に通らない取引は、有料機能の根拠にしない
            guard case .verified(let tx) = result else { continue }
            guard proProductIDs.contains(tx.productID) else { continue }
            // 返金・取り消しされた取引と、期限切れを外す
            guard tx.revocationDate == nil else { continue }
            if let exp = tx.expirationDate, exp < Date.now { continue }
            best = .active(productID: tx.productID,
                           ownership: tx.ownershipType,
                           expires: tx.expirationDate)
        }
        return best
    }
}

func startListening(onChange: @escaping @Sendable () async -> Void) -> Task<Void, Never> {
    Task.detached {
        for await update in Transaction.updates {
            if case .verified(let tx) = update {
                await tx.finish()
                await onChange()
            }
        }
    }
}

import StoreKitTest
import XCTest
 
final class EntitlementTests: XCTestCase {
    var session: SKTestSession!
 
    override func setUpWithError() throws {
        session = try SKTestSession(configurationFileNamed: "Products")
        session.resetToDefaultState()
        session.clearTransactions()
        session.disableDialogs = true
    }
 
    func testActiveAfterPurchase() async throws {
        _ = try await session.buyProduct(productIdentifier: "pro.monthly")
        let access = await EntitlementResolver(proProductIDs: ["pro.monthly"]).current()
        guard case .active = access else { return XCTFail("購入直後なのに権限が無い") }
    }
 
    func testNoneAfterExpire() async throws {
        _ = try await session.buyProduct(productIdentifier: "pro.monthly")
        try session.expireSubscription(productIdentifier: "pro.monthly")
        let access = await EntitlementResolver(proProductIDs: ["pro.monthly"]).current()
        XCTAssertEqual(access, .none)
    }
}

# decisions/multiseat-2026-10.yaml
decided_on: 2026-10-01
review_on: 2026-11-15          # 実際の取引を見て見直す日
products:
  - id: pro.monthly
    multiseat: off             # on / off
    reasons:
      q1_value_is_personal: true
      q2_price_works_per_seat: unknown
      q3_support_capacity: false
      q4_entitlement_code_ready: true   # EntitlementResolver に集約済み
    note: "2が unknown のため、外す側に倒した。見直し日に取引を見て再判断"