[#602] Improve error logging for InitializerError and RustWeldingError

Sources/ZcashLightClientKit/Initializer.swift

@@ -13,10 +13,9 @@ Wrapper for the Rust backend. This class basically represents all the Rust-walle
 capabilities and the supporting data required to exercise those abilities.
 */
 public enum InitializerError: Error {
-    case cacheDbInitFailed
-    case dataDbInitFailed
-    case accountInitFailed
-    case falseStart
+    case cacheDbInitFailed(Error)
+    case dataDbInitFailed(Error)
+    case accountInitFailed(Error)
     case invalidViewingKey(key: String)
 }
 
@@ -197,7 +196,7 @@ public class Initializer {
         do {
             try storage.createTable()
         } catch {
-            throw InitializerError.cacheDbInitFailed
+            throw InitializerError.cacheDbInitFailed(error)
         }
         
         do {
@@ -205,7 +204,7 @@ public class Initializer {
                 return .seedRequired
             }
         } catch {
-            throw InitializerError.dataDbInitFailed
+            throw InitializerError.dataDbInitFailed(error)
         }
 
         let checkpoint = Checkpoint.birthday(with: self.walletBirthday, network: network)
@@ -221,7 +220,7 @@ public class Initializer {
         } catch RustWeldingError.dataDbNotEmpty {
             // this is fine
         } catch {
-            throw InitializerError.dataDbInitFailed
+            throw InitializerError.dataDbInitFailed(error)
         }
         self.walletBirthday = checkpoint.height
         
@@ -230,19 +229,17 @@ public class Initializer {
         lowerBoundHeight = max(walletBirthday, lastDownloaded)
  
         do {
-            guard try rustBackend.initAccountsTable(
+            try rustBackend.initAccountsTable(
                 dbData: dataDbURL,
                 ufvks: viewingKeys,
                 networkType: network.networkType
-            ) else {
-                throw rustBackend.lastError() ?? InitializerError.accountInitFailed
-            }
+            )
         } catch RustWeldingError.dataDbNotEmpty {
             // this is fine
         } catch RustWeldingError.malformedStringInput {
             throw RustWeldingError.malformedStringInput
         } catch {
-            throw rustBackend.lastError() ?? InitializerError.accountInitFailed
+            throw InitializerError.accountInitFailed(error)
         }
 
         let migrationManager = MigrationManager(
@@ -371,3 +368,19 @@ enum CompactBlockProcessorBuilder {
         )
     }
 }
+
+
+extension InitializerError: LocalizedError {
+    public var errorDescription: String? {
+        switch self {
+        case .invalidViewingKey:
+            return "The provided viewing key is invalid"
+        case .cacheDbInitFailed(let error):
+            return "cacheDb Init failed with error: \(error.localizedDescription)"
+        case .dataDbInitFailed(let error):
+            return "dataDb init failed with error: \(error.localizedDescription)"
+        case .accountInitFailed(let error):
+            return "account table init failed with error: \(error.localizedDescription)"
+        }
+    }
+}

Sources/ZcashLightClientKit/Rust/ZcashRustBackend.swift

@@ -434,7 +434,7 @@ class ZcashRustBackend: ZcashRustBackendWelding {
         dbData: URL,
         ufvks: [UnifiedFullViewingKey],
         networkType: NetworkType
-    ) throws -> Bool {
+    ) throws {
         let dbData = dbData.osStr()
         
         var ffiUfvks = [FFIEncodedKey]()
@@ -470,14 +470,16 @@ class ZcashRustBackend: ZcashRustBackendWelding {
                 networkType.networkId
             )
         }
-        
+
         defer {
             for ufvk in ffiUfvks {
                 ufvk.encoding.deallocate()
             }
         }
-        
-        return result
+
+        guard result else {
+            throw lastError() ?? .genericError(message: "`initAccountsTable` failed with unknown error")
+        }
     }
     
     // swiftlint:disable function_parameter_count
@@ -730,3 +732,28 @@ extension UnsafeMutablePointer where Pointee == UInt8 {
     }
 }
     
+
+extension RustWeldingError: LocalizedError {
+    var errorDescription: String? {
+        switch self {
+        case .genericError(let message):
+            return "RustWeldingError generic error: \(message)"
+        case .dataDbInitFailed(let message):
+            return "`RustWeldingError.dataDbInitFailed` with message: \(message)"
+        case .dataDbNotEmpty:
+            return "`.DataDbNotEmpty`. This is usually not an error."
+        case .invalidInput(let message):
+            return "`RustWeldingError.invalidInput` with message: \(message)"
+        case .malformedStringInput:
+            return "`.malformedStringInput` Called a function with a malformed string input."
+        case .invalidRewind:
+            return "`.invalidRewind` called the rewind API with an arbitrary height that is not valid."
+        case .noConsensusBranchId(let branchId):
+            return "`.noConsensusBranchId` number \(branchId)"
+        case .saplingSpendParametersNotFound:
+            return "`.saplingSpendParametersNotFound` sapling parameters not present at specified URL"
+        case .unableToDeriveKeys:
+            return "`.unableToDeriveKeys` the requested keys could not be derived from the source provided"
+        }
+    }
+}

Sources/ZcashLightClientKit/Rust/ZcashRustBackendWelding.swift

@@ -245,7 +245,7 @@ protocol ZcashRustBackendWelding {
         dbData: URL,
         ufvks: [UnifiedFullViewingKey],
         networkType: NetworkType
-    ) throws -> Bool
+    ) throws
 
     /// initializes the data db. This will performs any migrations needed on the sqlite file
     /// provided. Some migrations might need that callers provide the seed bytes.

Tests/DarksideTests/TransactionEnhancementTests.swift

@@ -74,11 +74,13 @@ class TransactionEnhancementTests: XCTestCase {
                 }
 
         ]
-        guard try rustBackend.initAccountsTable(
-            dbData: processorConfig.dataDb,
-            ufvks: ufvks,
-            networkType: network.networkType
-        ) else {
+        do {
+            try rustBackend.initAccountsTable(
+                dbData: processorConfig.dataDb,
+                ufvks: ufvks,
+                networkType: network.networkType
+            )
+        } catch {
             XCTFail("Failed to init accounts table error: " + String(describing: rustBackend.getLastError()))
             return
         }

Tests/NetworkTests/BlockScanTests.swift

@@ -131,11 +131,13 @@ class BlockScanTests: XCTestCase {
             .map { try derivationTool.deriveUnifiedFullViewingKey(from: $0) }
 
 
-        guard try self.rustWelding.initAccountsTable(
-            dbData: self.dataDbURL,
-            ufvks: [ufvk],
-            networkType: network.networkType
-        ) else {
+        do {
+            try self.rustWelding.initAccountsTable(
+                dbData: self.dataDbURL,
+                ufvks: [ufvk],
+                networkType: network.networkType
+            )
+        } catch {
             XCTFail("failed to init account table. error: \(self.rustWelding.getLastError() ?? "no error found")")
             return
         }

Tests/OfflineTests/ZcashRustBackendTests.swift

@@ -71,10 +71,13 @@ class ZcashRustBackendTests: XCTestCase {
                 .deriveFullViewingKey()
 
         ]
-        guard try ZcashRustBackend.initAccountsTable(dbData: dbData!, ufvks: ufvks, networkType: networkType) else {
+        do {
+            try ZcashRustBackend.initAccountsTable(dbData: dbData!, ufvks: ufvks, networkType: networkType)
+        } catch {
             XCTFail("failed with error: \(String(describing: ZcashRustBackend.lastError()))")
             return
         }
+        
         XCTAssertNotNil(
             try ZcashRustBackend.createAccount(
                 dbData: dbData!,

Tests/TestUtils/Stubs.swift

@@ -55,6 +55,10 @@ extension LightWalletServiceMockResponse {
 }
 
 class MockRustBackend: ZcashRustBackendWelding {
+    static func initAccountsTable(dbData: URL, ufvks: [ZcashLightClientKit.UnifiedFullViewingKey], networkType: ZcashLightClientKit.NetworkType) throws {
+        
+    }
+
     static func createToAddress(dbData: URL, usk: ZcashLightClientKit.UnifiedSpendingKey, to address: String, value: Int64, memo: ZcashLightClientKit.MemoBytes?, spendParamsPath: String, outputParamsPath: String, networkType: ZcashLightClientKit.NetworkType) -> Int64 {
         -1
     }