Add jsonb support (vapor#36)

* Add jsonb support

* Keep JSONEncoder and JSONDecoder error for PostgresData convert

* Rename JSONBCodable to PostgresJSONBCodable

Author: vkill

README.md

@@ -198,6 +198,8 @@ print(data.uint64) // UInt64?
 
 print(data.bool) // Bool?
 
+print(try data.jsonb(as: Foo.self)) // Foo?
+
 print(data.float) // Float?
 print(data.double) // Double?
 

Sources/PostgresNIO/Data/PostgresData+JSONB.swift

@@ -0,0 +1,64 @@
+import Foundation
+
+fileprivate let jsonBVersionBytes: [UInt8] = [0x01]
+
+extension PostgresData {
+    public init(jsonb jsonData: Data) {
+        let jsonBDataBytes = [UInt8](jsonData)
+        
+        var buffer = ByteBufferAllocator().buffer(capacity: jsonBVersionBytes.count + jsonBDataBytes.count)
+        buffer.writeBytes(jsonBVersionBytes)
+        buffer.writeBytes(jsonBDataBytes)
+        
+        self.init(type: .jsonb, formatCode: .binary, value: buffer)
+    }
+
+    public init<T>(jsonb value: T) throws where T: Encodable {
+        let jsonData = try JSONEncoder().encode(value)
+        self.init(jsonb: jsonData)
+    }
+
+    public var jsonb: Data? {
+        guard var value = self.value 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 {
+            return nil
+        }
+
+        return Data(dataBytes)
+    }
+
+    public func jsonb<T>(as type: T.Type) throws -> T? where T: Decodable {
+        guard let jsonData = jsonb else {
+            return nil
+        }
+
+        return try JSONDecoder().decode(T.self, from: jsonData)
+    }
+}
+
+public protocol PostgresJSONBCodable: Codable, PostgresDataConvertible {
+}
+
+extension PostgresJSONBCodable {
+    public static var postgresDataType: PostgresDataType {
+        return .jsonb
+    }
+    
+    public var postgresData: PostgresData? {
+        return try? .init(jsonb: self)
+    }
+    
+    public init?(postgresData: PostgresData) {
+        guard let value = try? postgresData.jsonb(as: Self.self) else {
+            return nil
+        }
+        self = value
+    }
+}

Tests/PostgresNIOTests/NIOPostgresTests.swift

@@ -387,6 +387,48 @@ final class NIOPostgresTests: XCTestCase {
         }
     }
 
+    func testJSONBSerialize() throws {
+        struct Object: Codable {
+            let foo: Int
+            let bar: Int
+        }
+        
+        let conn = try PostgresConnection.test(on: eventLoop).wait()
+        defer { try! conn.close().wait() }
+        do {
+            let postgresData = try PostgresData(jsonb: Object(foo: 1, bar: 2))
+            let rows = try conn.query("select $1::jsonb as jsonb", [postgresData]).wait()
+            
+            let object = try rows[0].column("jsonb")?.jsonb(as: Object.self)
+            XCTAssertEqual(object?.foo, 1)
+            XCTAssertEqual(object?.bar, 2)
+        }
+        
+        do {
+            let rows = try conn.query("select jsonb_build_object('foo',1,'bar',2) as jsonb").wait()
+            
+            let object = try rows[0].column("jsonb")?.jsonb(as: Object.self)
+            XCTAssertEqual(object?.foo, 1)
+            XCTAssertEqual(object?.bar, 2)
+        }
+    }
+    
+    func testJSONBConvertible() throws {
+        struct Object: PostgresJSONBCodable {
+            let foo: Int
+            let bar: Int
+        }
+
+        XCTAssertEqual(Object.postgresDataType, .jsonb)
+
+        let postgresData = Object(foo: 1, bar: 2).postgresData
+        XCTAssertEqual(postgresData?.type, .jsonb)
+        
+        let object = Object(postgresData: postgresData!)
+        XCTAssertEqual(object?.foo, 1)
+        XCTAssertEqual(object?.bar, 2)
+    }
+    
     func testRemoteTLSServer() throws {
         let url = "postgres://uymgphwj:7_tHbREdRwkqAdu4KoIS7hQnNxr8J1LA@elmer.db.elephantsql.com:5432/uymgphwj"
         let elg = MultiThreadedEventLoopGroup(numberOfThreads: 1)

Tests/PostgresNIOTests/XCTestManifests.swift

@@ -9,6 +9,8 @@ extension NIOPostgresTests {
         ("testAverageLengthNumeric", testAverageLengthNumeric),
         ("testBindInteger", testBindInteger),
         ("testBoolSerialize", testBoolSerialize),
+        ("testJSONBSerialize", testJSONBSerialize),
+        ("testJSONBConvertible", testJSONBConvertible),
         ("testColumnsInJoin", testColumnsInJoin),
         ("testConnectAndClose", testConnectAndClose),
         ("testDates", testDates),