Connection Wrapper

Author: wickwirew

Sources/Compiler/Gen/SwiftLanguage.swift

@@ -209,7 +209,7 @@ public struct SwiftLanguage: Language {
     }
 
     private func queriesProtocol(name: String, queries: [GeneratedQuery]) {
-        writer.write(line: "protocol ", name, " {")
+        writer.write(line: "protocol ", name, ": ConnectionWrapper {")
 
         writer.indent()
 
@@ -228,6 +228,8 @@ public struct SwiftLanguage: Language {
         writer.write(line: "struct ", name, "Noop: ", name, " {")
         writer.indent()
 
+        writer.write(line: "let connection: any Connection = NoopConnection()")
+        
         for query in queries {
             writer.write(line: "let ")
             writer.write(query.variableName)

Sources/Otter/Connection.swift

@@ -9,27 +9,54 @@
 /// directly mapped to a default SQLite connection like `SQLiteConnection`
 /// but is a much more high level of abstraction that allows for safe
 /// communication to a database.
-public protocol Connection: Actor {
+public protocol Connection: Sendable {
     /// Starts observation for the given subscriber
-    nonisolated func observe(subscriber: DatabaseSubscriber)
+    func observe(subscriber: DatabaseSubscriber)
 
     /// Cancels the observation for the given subscriber
-    nonisolated func cancel(subscriber: DatabaseSubscriber)
+    func cancel(subscriber: DatabaseSubscriber)
 
     func begin<Output>(
         _ kind: Transaction.Kind,
-        execute: (borrowing Transaction) throws -> Output
+        execute: @Sendable (borrowing Transaction) throws -> Output
     ) async throws -> Output
 }
 
-actor NoopConnection: Connection {
-    nonisolated func observe(subscriber: any DatabaseSubscriber) {}
-    nonisolated func cancel(subscriber: any DatabaseSubscriber) {}
+/// A no operation database connection that does nothing.
+struct NoopConnection: Connection {
+    func observe(subscriber: any DatabaseSubscriber) {}
+    func cancel(subscriber: any DatabaseSubscriber) {}
 
     func begin<Output>(
         _ kind: Transaction.Kind,
-        execute: (borrowing Transaction) throws -> Output
+        execute: @Sendable (borrowing Transaction) throws -> Output
     ) async throws -> Output {
         try execute(Transaction(connection: NoopRawConnection(), kind: kind))
     }
 }
+
+/// A type that has a database connection.
+/// Useful for the queries structures.
+///
+/// Note: This should not be explicitly used and is
+/// intended only for the codegen.
+public protocol ConnectionWrapper: Connection {
+    var connection: any Connection { get }
+}
+
+extension ConnectionWrapper {
+    func observe(subscriber: DatabaseSubscriber) {
+        connection.observe(subscriber: subscriber)
+    }
+
+    func cancel(subscriber: DatabaseSubscriber) {
+        connection.cancel(subscriber: subscriber)
+    }
+
+    func begin<Output>(
+        _ kind: Transaction.Kind,
+        execute: @Sendable (borrowing Transaction) throws -> Output
+    ) async throws -> Output {
+        try await connection.begin(kind, execute: execute)
+    }
+}

Sources/Otter/ConnectionPool.swift

@@ -128,9 +128,9 @@ extension ConnectionPool: Connection {
     }
 
     /// Starts a transaction.
-    public func begin<Output: Sendable>(
+    public nonisolated func begin<Output: Sendable>(
         _ kind: Transaction.Kind,
-        execute: (borrowing Transaction) throws -> Output
+        execute: @Sendable (borrowing Transaction) throws -> Output
     ) async throws -> Output {
         try await beginNoCommit(kind) { tx in
             // The `Result` wrapper seems weird, but allows us to keep
@@ -162,7 +162,7 @@ extension ConnectionPool: Connection {
     /// makes sure it reclaims the connection.
     public func beginNoCommit<Output: Sendable>(
         _ kind: Transaction.Kind,
-        execute: (consuming Transaction) async throws -> Output
+        execute: @Sendable (consuming Transaction) async throws -> Output
     ) async throws -> Output {
         let tx = try await begin(kind)
         let conn = tx.connection

Tests/CompilerTests/Gen/Swift.output

@@ -182,7 +182,7 @@ struct SelectWithOptionalInterestOutput: Hashable, Sendable, RowDecodable {
     }
 }
 
-protocol QueriesQueries {
+protocol QueriesQueries: ConnectionWrapper {
     associatedtype _InsertUser: InsertUserQuery
     var insertUser: _InsertUser { get }
     associatedtype _SelectUsers: SelectUsersQuery
@@ -202,6 +202,7 @@ protocol QueriesQueries {
 }
 
 struct QueriesQueriesNoop: QueriesQueries {
+    let connection: any Connection = NoopConnection()
     let insertUser: AnyQuery<InsertUserInput, ()>
     let selectUsers: AnyQuery<(), [User]>
     let selectUserById: AnyQuery<Int, User?>