add PostgresData+JSON support

Sources/PostgresNIO/Data/PostgresData+JSON.swift

@@ -0,0 +1,56 @@
+import Foundation
+
+extension PostgresData {
+    public init(json jsonData: Data) {
+        let jsonData = [UInt8](jsonData)
+
+        var buffer = ByteBufferAllocator()
+            .buffer(capacity: jsonData.count)
+        buffer.writeBytes(jsonData)
+        self.init(type: .json, formatCode: .binary, value: buffer)
+    }
+
+    public init<T>(json value: T) throws where T: Encodable {
+        let jsonData = try JSONEncoder().encode(value)
+        self.init(json: jsonData)
+    }
+
+    public var json: Data? {
+        guard var value = self.value else {
+            return nil
+        }
+        guard case .json = self.type else {
+            return nil
+        }
+        guard let data = value.readBytes(length: value.readableBytes) else {
+            return nil
+        }
+        return Data(data)
+    }
+
+    public func json<T>(as type: T.Type) throws -> T? where T: Decodable {
+        guard let data = self.json else {
+            return nil
+        }
+        return try JSONDecoder().decode(T.self, from: data)
+    }
+}
+
+public protocol PostgresJSONCodable: Codable, PostgresDataConvertible { }
+
+extension PostgresJSONCodable {
+    public static var postgresDataType: PostgresDataType {
+        return .json
+    }
+
+    public var postgresData: PostgresData? {
+        return try? .init(json: self)
+    }
+
+    public init?(postgresData: PostgresData) {
+        guard let value = try? postgresData.json(as: Self.self) else {
+            return nil
+        }
+        self = value
+    }
+}

Sources/PostgresNIO/Data/PostgresData+JSONB.swift

@@ -4,12 +4,12 @@ fileprivate let jsonBVersionBytes: [UInt8] = [0x01]
 
 extension PostgresData {
     public init(jsonb jsonData: Data) {
-        let jsonBDataBytes = [UInt8](jsonData)
+        let jsonBData = [UInt8](jsonData)
 
         var buffer = ByteBufferAllocator()
-            .buffer(capacity: jsonBVersionBytes.count + jsonBDataBytes.count)
+            .buffer(capacity: jsonBVersionBytes.count + jsonBData.count)
         buffer.writeBytes(jsonBVersionBytes)
-        buffer.writeBytes(jsonBDataBytes)
+        buffer.writeBytes(jsonBData)
 
         self.init(type: .jsonb, formatCode: .binary, value: buffer)
     }
@@ -23,29 +23,31 @@ extension PostgresData {
         guard var value = self.value else {
             return nil
         }
+        guard case .jsonb = self.type else {
+            return nil
+        }
 
         guard let versionBytes = value.readBytes(length: jsonBVersionBytes.count), [UInt8](versionBytes) == jsonBVersionBytes else {
             return nil
         }
 
-        guard let dataBytes = value.readBytes(length: value.readableBytes) else {
+        guard let data = value.readBytes(length: value.readableBytes) else {
             return nil
         }
 
-        return Data(dataBytes)
+        return Data(data)
     }
 
     public func jsonb<T>(as type: T.Type) throws -> T? where T: Decodable {
-        guard let jsonData = jsonb else {
+        guard let data = jsonb else {
             return nil
         }
 
-        return try JSONDecoder().decode(T.self, from: jsonData)
+        return try JSONDecoder().decode(T.self, from: data)
     }
 }
 
-public protocol PostgresJSONBCodable: Codable, PostgresDataConvertible {
-}
+public protocol PostgresJSONBCodable: Codable, PostgresDataConvertible { }
 
 extension PostgresJSONBCodable {
     public static var postgresDataType: PostgresDataType {