[Electric-Coin-Company#1204] Expose ZIP 317

- the flag can be turned on/off via new public API
- changelog updated
- unit tests for the toggle added

CHANGELOG.md

@@ -12,6 +12,11 @@ be able to write to this location after it creates this directory. It is suggest
 a subdirectory of the `Documents` directory. If this information is stored in `Documents` then the
 system itself won't remove these data.
 
+### [#1204] Expose ZIP 317
+
+The SDK has been prepared but untested for ZIP 317 proposal for a while. Internally it uses a flag `useZIP317Fees` but it's been hardcoded to false.
+Ticket #1024 exposes new public API that allows users to turn the flag on/off. Synchronizer now offers an async method `useZIP317Fees(Bool)`.
+
 # 0.22.0-beta
 
 ## Checkpoints

Sources/ZcashLightClientKit/Rust/ZcashRustBackend.swift

@@ -11,7 +11,7 @@ import libzcashlc
 
 actor ZcashRustBackend: ZcashRustBackendWelding {
     let minimumConfirmations: UInt32 = 10
-    let useZIP317Fees = false
+    var useZIP317Fees = false
 
     let dbData: (String, UInt)
     let fsBlockDbRoot: (String, UInt)
@@ -647,6 +647,10 @@ actor ZcashRustBackend: ZcashRustBackendWelding {
 
         return branchId
     }
+
+    func useZIP317Fees(_ state: Bool) async {
+        useZIP317Fees = state
+    }
 }
 
 private extension ZcashRustBackend {

Sources/ZcashLightClientKit/Rust/ZcashRustBackendWelding.swift

@@ -243,4 +243,7 @@ protocol ZcashRustBackendWelding {
     /// format `{height}-{hash}-block`. This directory has must be granted both write and read permissions.
     /// - Returns `BlockHeight` of the latest cached block or `.empty` if no blocks are stored.
     func latestCachedBlockHeight() async -> BlockHeight
+
+    /// The SDK previously hardcoded the ZIP 317 flag to `false`. This API allows users to turn it on/off.
+    func useZIP317Fees(_ state: Bool) async
 }

Sources/ZcashLightClientKit/Synchronizer.swift

@@ -289,6 +289,9 @@ public protocol Synchronizer: AnyObject {
     /// - Parameter policy: the rewind policy
     func rewind(_ policy: RewindPolicy) -> AnyPublisher<Void, Error>
 
+    /// The SDK previously hardcoded the ZIP 317 flag to `false`. This API allows users to turn it on/off.
+    func useZIP317Fees(_ state: Bool) async
+
     /// Wipes out internal data structures of the SDK. After this call, everything is the same as before any sync. The state of the synchronizer is
     /// switched to `unprepared`. So before the next sync, it's required to call `prepare()`.
     ///

Sources/ZcashLightClientKit/Synchronizer/SDKSynchronizer.swift

@@ -508,6 +508,12 @@ public class SDKSynchronizer: Synchronizer {
         return subject.eraseToAnyPublisher()
     }
 
+    // MARK: Zip 317 fees
+
+    public func useZIP317Fees(_ state: Bool) async {
+        await initializer.rustBackend.useZIP317Fees(state)
+    }
+
     // MARK: Wipe
 
     public func wipe() -> AnyPublisher<Void, Error> {

Tests/OfflineTests/SynchronizerOfflineTests.swift

@@ -475,6 +475,49 @@ class SynchronizerOfflineTests: ZcashTestCase {
         }
     }
 
+    func testUseZIP317FeesToggle() async throws {
+        let validFileURL = URL(fileURLWithPath: "/some/valid/path/to.file")
+        let validDirectoryURL = URL(fileURLWithPath: "/some/valid/path/to/directory")
+        let invalidPathURL = URL(string: "https://whatever")!
+
+        let initializer = Initializer(
+            cacheDbURL: nil,
+            fsBlockDbRoot: validDirectoryURL,
+            generalStorageURL: validDirectoryURL,
+            dataDbURL: invalidPathURL,
+            endpoint: LightWalletEndpointBuilder.default,
+            network: ZcashNetworkBuilder.network(for: .testnet),
+            spendParamsURL: validFileURL,
+            outputParamsURL: validFileURL,
+            saplingParamsSourceURL: .default,
+            alias: .default,
+            loggingPolicy: .default(.debug)
+        )
+
+        XCTAssertNotNil(initializer.urlsParsingError)
+
+        let synchronizer = SDKSynchronizer(initializer: initializer)
+
+        let backend = initializer.container.resolve(ZcashRustBackendWelding.self)
+
+        guard let rustBackend = backend as? ZcashRustBackend else {
+            return XCTFail()
+        }
+
+        let unused = await rustBackend.useZIP317Fees
+        XCTAssertFalse(unused)
+
+        await synchronizer.useZIP317Fees(true)
+
+        let used = await rustBackend.useZIP317Fees
+        XCTAssertTrue(used)
+
+        await synchronizer.useZIP317Fees(false)
+
+        let unusedAgain = await rustBackend.useZIP317Fees
+        XCTAssertFalse(unusedAgain)
+    }
+
     func synchronizerState(for internalSyncStatus: InternalSyncStatus) -> SynchronizerState {
         SynchronizerState(
             syncSessionID: .nullID,

Tests/TestUtils/Sourcery/GeneratedMocks/AutoMockable.generated.swift

@@ -1484,6 +1484,21 @@ class SynchronizerMock: Synchronizer {
         }
     }
 
+    // MARK: - useZIP317Fees
+
+    var useZIP317FeesCallsCount = 0
+    var useZIP317FeesCalled: Bool {
+        return useZIP317FeesCallsCount > 0
+    }
+    var useZIP317FeesReceivedState: Bool?
+    var useZIP317FeesClosure: ((Bool) async -> Void)?
+
+    func useZIP317Fees(_ state: Bool) async {
+        useZIP317FeesCallsCount += 1
+        useZIP317FeesReceivedState = state
+        await useZIP317FeesClosure!(state)
+    }
+
     // MARK: - wipe
 
     var wipeCallsCount = 0
@@ -2767,4 +2782,22 @@ actor ZcashRustBackendWeldingMock: ZcashRustBackendWelding {
         }
     }
 
+    // MARK: - useZIP317Fees
+
+    var useZIP317FeesCallsCount = 0
+    var useZIP317FeesCalled: Bool {
+        return useZIP317FeesCallsCount > 0
+    }
+    var useZIP317FeesReceivedState: Bool?
+    var useZIP317FeesClosure: ((Bool) async -> Void)?
+    func setUseZIP317FeesClosure(_ param: ((Bool) async -> Void)?) async {
+        useZIP317FeesClosure = param
+    }
+
+    func useZIP317Fees(_ state: Bool) async {
+        useZIP317FeesCallsCount += 1
+        useZIP317FeesReceivedState = state
+        await useZIP317FeesClosure!(state)
+    }
+
 }