Fix block production (#195)

* add failing test

* fix schedule block timing on short epoch

Blockchain/Sources/Blockchain/Config/ProtocolConfig+Timing.swift

@@ -20,7 +20,10 @@ extension ProtocolConfigRef {
     }
 
     public var prepareEpochStartTimeDelta: TimeInterval {
-        -TimeInterval(value.slotPeriodSeconds) * 3
+        if value.epochLength < 15 {
+            return -TimeInterval(value.slotPeriodSeconds)
+        }
+        return -TimeInterval(value.slotPeriodSeconds) * 3
     }
 
     public func scheduleTimeForAuthoring(timeslot: TimeslotIndex) -> TimeInterval {

Blockchain/Sources/Blockchain/RuntimeProtocols/Runtime.swift

@@ -76,7 +76,7 @@ public final class Runtime {
         // offendersMarkers is validated at apply time by Disputes
     }
 
-    public func validateHeaderSeal(block: BlockRef, state: inout State) throws(Error) {
+    public func validateHeaderSeal(block: BlockRef, state: inout State, prevState: StateRef) throws(Error) {
         let vrfOutput: Data32
         let blockAuthorKey = try Result {
             try Bandersnatch.PublicKey(data: state.currentValidators[Int(block.header.authorIndex)].bandersnatch)
@@ -87,7 +87,7 @@ public final class Runtime {
         switch state.safroleState.ticketsOrKeys {
         case let .left(tickets):
             let ticket = tickets[Int(index)]
-            let vrfInputData = SigningContext.safroleTicketInputData(entropy: state.entropyPool.t3, attempt: ticket.attempt)
+            let vrfInputData = SigningContext.safroleTicketInputData(entropy: prevState.value.entropyPool.t3, attempt: ticket.attempt)
             vrfOutput = try Result {
                 try blockAuthorKey.ietfVRFVerify(
                     vrfInputData: vrfInputData,
@@ -107,16 +107,17 @@ public final class Runtime {
                 logger.debug("expected key: \(key.toHexString()), got key: \(blockAuthorKey.data.toHexString())")
                 throw Error.invalidAuthorKey
             }
-            let vrfInputData = SigningContext.fallbackSealInputData(entropy: state.entropyPool.t3)
+            let vrfInputData = SigningContext.fallbackSealInputData(entropy: prevState.value.entropyPool.t3)
             vrfOutput = try Result {
-                try blockAuthorKey.ietfVRFVerify(
+                logger.trace("verifying ticket", metadata: ["key": "\(blockAuthorKey.data.toHexString())"])
+                return try blockAuthorKey.ietfVRFVerify(
                     vrfInputData: vrfInputData,
                     auxData: encodedHeader,
                     signature: block.header.seal
                 )
             }.mapError(Error.invalidBlockSeal).get()
 
-            entropyVRFInputData = SigningContext.fallbackSealInputData(entropy: state.entropyPool.t3)
+            entropyVRFInputData = SigningContext.fallbackSealInputData(entropy: prevState.value.entropyPool.t3)
         }
 
         _ = try Result {
@@ -156,7 +157,14 @@ public final class Runtime {
         do {
             try updateSafrole(block: block, state: &newState)
 
-            try validateHeaderSeal(block: block, state: &newState)
+            if newState.ticketsOrKeys != prevState.value.ticketsOrKeys {
+                logger.trace("state tickets changed", metadata: [
+                    "old": "\(prevState.value.ticketsOrKeys)",
+                    "new": "\(newState.ticketsOrKeys)",
+                ])
+            }
+
+            try validateHeaderSeal(block: block, state: &newState, prevState: prevState)
 
             try updateDisputes(block: block, state: &newState)
 

Blockchain/Sources/Blockchain/Validator/BlockAuthor.swift

@@ -44,13 +44,13 @@ public final class BlockAuthor: ServiceBase2, @unchecked Sendable {
     public func createNewBlock(
         timeslot: TimeslotIndex,
         claim: Either<(TicketItemAndOutput, Bandersnatch.PublicKey), Bandersnatch.PublicKey>
-    ) async throws
-        -> BlockRef
-    {
+    ) async throws -> BlockRef {
         let parentHash = await dataProvider.bestHead.hash
 
         logger.trace("creating new block for timeslot: \(timeslot) with parent hash: \(parentHash)")
 
+        // TODO: verify we are indeed the block author
+
         let state = try await dataProvider.getState(hash: parentHash)
         let epoch = timeslot.timeslotToEpochIndex(config: config)
 
@@ -175,8 +175,15 @@ public final class BlockAuthor: ServiceBase2, @unchecked Sendable {
             tickets.value = []
             let timeslot = epoch.epochToTimeslotIndex(config: config)
 
-            let bestHead = await dataProvider.bestHead.hash
-            let state = try await dataProvider.getState(hash: bestHead)
+            let bestHead = await dataProvider.bestHead
+
+            let bestHeadTimeslot = bestHead.timeslot
+            let bestHeadEpoch = bestHeadTimeslot.timeslotToEpochIndex(config: config)
+            if bestHeadEpoch + 1 != epoch {
+                logger.warning("best head epoch \(bestHeadEpoch) is too far from current epoch \(epoch)")
+            }
+
+            let state = try await dataProvider.getState(hash: bestHead.hash)
 
             // simulate next block to determine the block authors for next epoch
             let res = try state.value.updateSafrole(
@@ -187,6 +194,10 @@ public final class BlockAuthor: ServiceBase2, @unchecked Sendable {
                 extrinsics: .dummy(config: config)
             )
 
+            logger.trace("expected safrole tickets", metadata: [
+                "tickets": "\(res.state.ticketsOrKeys)", "epoch": "\(epoch)", "parentTimeslot": "\(bestHead.timeslot)",
+            ])
+
             await scheduleNewBlocks(ticketsOrKeys: res.state.ticketsOrKeys, timeslot: timeslot)
         }
     }

Blockchain/Sources/Blockchain/Validator/DevKeyStore.swift

@@ -28,6 +28,7 @@ public final class DevKeyStore: KeyStore {
         await keystore.get(type, publicKey: publicKey)
     }
 
+    @discardableResult
     public func addDevKeys(seed: UInt32) async throws -> KeySet {
         var seedData = Data(repeating: 0, count: 32)
         seedData[0 ..< 4] = seed.encode()

Blockchain/Tests/BlockchainTests/BlockchainServices.swift

@@ -7,7 +7,7 @@ class BlockchainServices {
     let dataProvider: BlockchainDataProvider
     let eventBus: EventBus
     let scheduler: MockScheduler
-    let keystore: KeyStore
+    let keystore: DevKeyStore
     let storeMiddleware: StoreMiddleware
     let genesisBlock: BlockRef
     let genesisState: StateRef
@@ -20,7 +20,8 @@ class BlockchainServices {
 
     init(
         config: ProtocolConfigRef = .dev,
-        timeProvider: MockTimeProvider = MockTimeProvider(time: 988)
+        timeProvider: MockTimeProvider = MockTimeProvider(time: 988),
+        keysCount: Int = 12
     ) async {
         self.config = config
         self.timeProvider = timeProvider
@@ -35,7 +36,7 @@ class BlockchainServices {
 
         scheduler = MockScheduler(timeProvider: timeProvider)
 
-        keystore = try! await DevKeyStore()
+        keystore = try! await DevKeyStore(devKeysCount: keysCount)
     }
 
     deinit {

Blockchain/Tests/BlockchainTests/MockScheduler.swift

@@ -77,6 +77,7 @@ final class MockScheduler: Scheduler, Sendable {
     func advance(by interval: TimeInterval) async {
         let to = timeProvider.getTimeInterval() + interval
         while await advanceNext(to: to) {}
+        mockTimeProvider.advance(to: to)
     }
 
     func advanceNext(to time: TimeInterval) async -> Bool {

Blockchain/Tests/BlockchainTests/ValidatorServiceTests.swift

@@ -6,11 +6,17 @@ import Utils
 @testable import Blockchain
 
 struct ValidatorServiceTests {
-    func setup(time: TimeInterval = 988) async throws -> (BlockchainServices, ValidatorService) {
-        // setupTestLogger()
+    func setup(
+        config: ProtocolConfigRef = .dev,
+        time: TimeInterval = 988,
+        keysCount: Int = 12
+    ) async throws -> (BlockchainServices, ValidatorService) {
+        setupTestLogger()
 
         let services = await BlockchainServices(
-            timeProvider: MockTimeProvider(time: time)
+            config: config,
+            timeProvider: MockTimeProvider(time: time),
+            keysCount: keysCount
         )
         let validatorService = await ValidatorService(
             blockchain: services.blockchain,
@@ -112,4 +118,34 @@ struct ValidatorServiceTests {
 
         #expect(blockAuthoredEvents.count == 25)
     }
+
+    @Test
+    func makeManyBlocksWithSingleKey() async throws {
+        let (services, validatorService) = try await setup(
+            config: .minimal,
+            keysCount: 0
+        )
+        let genesisState = services.genesisState
+        let storeMiddleware = services.storeMiddleware
+        let config = services.config
+        let scheduler = services.scheduler
+        let keystore = services.keystore
+
+        try await keystore.addDevKeys(seed: 0)
+
+        await validatorService.on(genesis: genesisState)
+
+        await storeMiddleware.wait()
+
+        for _ in 0 ..< 50 {
+            await scheduler.advance(by: TimeInterval(config.value.slotPeriodSeconds))
+            await storeMiddleware.wait() // let events to be processed
+        }
+
+        let events = await storeMiddleware.wait()
+
+        let blockAuthoredEvents = events.filter { $0 is RuntimeEvents.BlockAuthored }
+
+        #expect(blockAuthoredEvents.count > 0)
+    }
 }