Introduces a RESP3Token wrapper struct around ByteBuffer (#71)

Co-authored-by: Fabian Fett <[email protected]>

Author: Joannis

Package.swift

@@ -50,6 +50,12 @@ let package = Package(
                 "RediStack"
             ]
         ),
+        .target(
+            name: "RESP3",
+            dependencies: [
+                .product(name: "NIOCore", package: "swift-nio"),
+            ]
+        ),
         .testTarget(
             name: "RediStackTests",
             dependencies: [
@@ -67,6 +73,15 @@ let package = Package(
                 .product(name: "NIO", package: "swift-nio")
             ]
         ),
+        .testTarget(
+            name: "RESP3Tests",
+            dependencies: [
+                "RESP3",
+                .product(name: "NIOCore", package: "swift-nio"),
+                .product(name: "NIOEmbedded", package: "swift-nio"),
+                .product(name: "NIOTestUtils", package: "swift-nio"),
+            ]
+        ),
         .testTarget(
             name: "RediStackIntegrationTests",
             dependencies: [

Sources/RESP3/RESP3Error.swift

@@ -0,0 +1,79 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the RediStack open source project
+//
+// Copyright (c) 2023 RediStack project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of RediStack project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+import NIOCore
+
+/// This error is thrown if a RESP3 package could not be decoded.
+///
+/// If you see this error, there a two potential reasons this might happen:
+///
+///   1. The Swift RESP3 implementation is wrong
+///   2. You are contacting an untrusted backend
+///
+struct RESP3ParsingError: Error {
+    struct Code: Hashable, Sendable, CustomStringConvertible {
+        private enum Base {
+            case invalidLeadingByte
+            case invalidData
+            case tooDeeplyNestedAggregatedTypes
+            case missingColonInVerbatimString
+            case canNotParseInteger
+            case canNotParseDouble
+            case canNotParseBigNumber
+        }
+
+        private let base: Base
+
+        private init(_ base: Base) {
+            self.base = base
+        }
+
+        static let invalidLeadingByte = Self.init(.invalidLeadingByte)
+        static let invalidData = Self.init(.invalidData)
+        static let tooDeeplyNestedAggregatedTypes = Self.init(.tooDeeplyNestedAggregatedTypes)
+        static let missingColonInVerbatimString = Self.init(.missingColonInVerbatimString)
+        static let canNotParseInteger = Self.init(.canNotParseInteger)
+        static let canNotParseDouble = Self.init(.canNotParseDouble)
+        static let canNotParseBigNumber = Self.init(.canNotParseBigNumber)
+
+        var description: String {
+            switch self.base {
+            case .invalidLeadingByte:
+                return "invalidLeadingByte"
+            case .invalidData:
+                return "invalidData"
+            case .tooDeeplyNestedAggregatedTypes:
+                return "tooDeeplyNestedAggregatedTypes"
+            case .missingColonInVerbatimString:
+                return "missingColonInVerbatimString"
+            case .canNotParseInteger:
+                return "canNotParseInteger"
+            case .canNotParseDouble:
+                return "canNotParseDouble"
+            case .canNotParseBigNumber:
+                return "canNotParseBigNumber"
+            }
+        }
+    }
+
+    var code: Code
+
+    var buffer: ByteBuffer
+}
+
+enum RESP3Error: Error, Equatable {
+    case dataMalformed
+    case invalidType(UInt8)
+    case tooDepplyNestedAggregatedTypes
+}