Allow bindings with optional values in PostgresBindings (#520)

Author: rgcottrell

Sources/PostgresNIO/New/PostgresQuery.swift

@@ -172,6 +172,16 @@ public struct PostgresBindings: Sendable, Hashable {
         try self.append(value, context: .default)
     }
 
+    @inlinable
+    public mutating func append<Value: PostgresThrowingDynamicTypeEncodable>(_ value: Optional<Value>) throws {
+        switch value {
+        case .none:
+            self.appendNull()
+        case let .some(value):
+            try self.append(value)
+        }
+    }
+
     @inlinable
     public mutating func append<Value: PostgresThrowingDynamicTypeEncodable, JSONEncoder: PostgresJSONEncoder>(
         _ value: Value,
@@ -181,11 +191,34 @@ public struct PostgresBindings: Sendable, Hashable {
         self.metadata.append(.init(value: value, protected: true))
     }
 
+    @inlinable
+    public mutating func append<Value: PostgresThrowingDynamicTypeEncodable, JSONEncoder: PostgresJSONEncoder>(
+        _ value: Optional<Value>,
+        context: PostgresEncodingContext<JSONEncoder>
+    ) throws {
+        switch value {
+        case .none:
+            self.appendNull()
+        case let .some(value):
+            try self.append(value, context: context)
+        }
+    }
+
     @inlinable
     public mutating func append<Value: PostgresDynamicTypeEncodable>(_ value: Value) {
         self.append(value, context: .default)
     }
 
+    @inlinable
+    public mutating func append<Value: PostgresDynamicTypeEncodable>(_ value: Optional<Value>) {
+        switch value {
+        case .none:
+            self.appendNull()
+        case let .some(value):
+            self.append(value)
+        }
+    }
+
     @inlinable
     public mutating func append<Value: PostgresDynamicTypeEncodable, JSONEncoder: PostgresJSONEncoder>(
         _ value: Value,
@@ -195,6 +228,19 @@ public struct PostgresBindings: Sendable, Hashable {
         self.metadata.append(.init(value: value, protected: true))
     }
 
+    @inlinable
+    public mutating func append<Value: PostgresDynamicTypeEncodable, JSONEncoder: PostgresJSONEncoder>(
+        _ value: Optional<Value>,
+        context: PostgresEncodingContext<JSONEncoder>
+    ) {
+        switch value {
+        case .none:
+            self.appendNull()
+        case let .some(value):
+            self.append(value, context: context)
+        }
+    }
+
     @inlinable
     mutating func appendUnprotected<Value: PostgresEncodable, JSONEncoder: PostgresJSONEncoder>(
         _ value: Value,

Tests/IntegrationTests/AsyncTests.swift

@@ -476,6 +476,87 @@ final class AsyncPostgresConnectionTests: XCTestCase {
             XCTFail("Unexpected error: \(String(describing: error))")
         }
     }
+
+    static let preparedStatementWithOptionalTestTable = "AsyncTestPreparedStatementWithOptionalTestTable"
+    func testPreparedStatementWithOptionalBinding() async throws {
+        let eventLoopGroup = MultiThreadedEventLoopGroup(numberOfThreads: 1)
+        defer { XCTAssertNoThrow(try eventLoopGroup.syncShutdownGracefully()) }
+        let eventLoop = eventLoopGroup.next()
+
+        struct InsertPreparedStatement: PostgresPreparedStatement {
+            static let name = "INSERT-AsyncTestPreparedStatementWithOptionalTestTable"
+
+            static let sql = #"INSERT INTO "\#(AsyncPostgresConnectionTests.preparedStatementWithOptionalTestTable)" (uuid) VALUES ($1);"#
+            typealias Row = ()
+
+            var uuid: UUID?
+
+            func makeBindings() -> PostgresBindings {
+                var bindings = PostgresBindings()
+                bindings.append(self.uuid)
+                return bindings
+            }
+
+            func decodeRow(_ row: PostgresNIO.PostgresRow) throws -> Row {
+                ()
+            }
+        }
+
+        struct SelectPreparedStatement: PostgresPreparedStatement {
+            static let name = "SELECT-AsyncTestPreparedStatementWithOptionalTestTable"
+
+            static let sql = #"SELECT id, uuid FROM "\#(AsyncPostgresConnectionTests.preparedStatementWithOptionalTestTable)" WHERE id <= $1;"#
+            typealias Row = (Int, UUID?)
+
+            var id: Int
+
+            func makeBindings() -> PostgresBindings {
+                var bindings = PostgresBindings()
+                bindings.append(self.id)
+                return bindings
+            }
+
+            func decodeRow(_ row: PostgresNIO.PostgresRow) throws -> Row {
+                try row.decode((Int, UUID?).self)
+            }
+        }
+
+        do {
+            try await withTestConnection(on: eventLoop) { connection in
+                try await connection.query("""
+                    CREATE TABLE IF NOT EXISTS "\(unescaped: Self.preparedStatementWithOptionalTestTable)" (
+                        id SERIAL PRIMARY KEY,
+                        uuid UUID
+                    )
+                    """,
+                    logger: .psqlTest
+                )
+
+                _ = try await connection.execute(InsertPreparedStatement(uuid: nil), logger: .psqlTest)
+                _ = try await connection.execute(InsertPreparedStatement(uuid: .init()), logger: .psqlTest)
+                _ = try await connection.execute(InsertPreparedStatement(uuid: nil), logger: .psqlTest)
+                _ = try await connection.execute(InsertPreparedStatement(uuid: .init()), logger: .psqlTest)
+                _ = try await connection.execute(InsertPreparedStatement(uuid: nil), logger: .psqlTest)
+
+                let rows = try await connection.execute(SelectPreparedStatement(id: 3), logger: .psqlTest)
+                var counter = 0
+                for try await (id, uuid) in rows {
+                    Logger.psqlTest.info("Received row", metadata: [
+                        "id": "\(id)", "uuid": "\(String(describing: uuid))"
+                    ])
+                    counter += 1
+                }
+
+                try await connection.query("""
+                    DROP TABLE "\(unescaped: Self.preparedStatementWithOptionalTestTable)";
+                    """,
+                    logger: .psqlTest
+                )
+            }
+        } catch {
+            XCTFail("Unexpected error: \(String(describing: error))")
+        }
+    }
 }
 
 extension XCTestCase {