Lower minimum macOS platform requirement, since we don't actually require something newer. Add AsyncSQLMigration.

Author: gwynne

Package.swift

@@ -4,7 +4,7 @@ import PackageDescription
 let package = Package(
     name: "sql-kit-extras",
     platforms: [
-        .macOS(.v13),
+        .macOS(.v10_15),
     ],
     products: [
         .library(name: "SQLKitExtras", targets: ["SQLKitExtras"]),

[email protected]

@@ -4,7 +4,7 @@ import PackageDescription
 let package = Package(
     name: "sql-kit-extras",
     platforms: [
-        .macOS(.v13),
+        .macOS(.v10_15),
     ],
     products: [
         .library(name: "SQLKitExtras", targets: ["SQLKitExtras"]),

Sources/SQLKitExtras/FluentSQLKitExtras/AsyncSQLMigration.swift

@@ -0,0 +1,37 @@
+import protocol SQLKit.SQLDatabase
+import protocol FluentKit.Database
+import protocol FluentKit.AsyncMigration
+
+/// A variant of `AsyncMigration` designed to simplify using SQLKit to write migrations.
+///
+/// > Warning: Use of ``AsyncSQLMigration`` will cause runtime errors if the migration is added to a Fluent
+/// > database which is not compatible with SQLKit (such as MongoDB).
+public protocol AsyncSQLMigration: AsyncMigration {
+    /// Perform the desired migration.
+    ///
+    /// - Parameter database: The database to migrate.
+    func prepare(on database: any SQLDatabase) async throws
+    
+    /// Reverse, if possible, the migration performed by `prepare(on:)`.
+    ///
+    /// It is not uncommon for a given migration to be lossy if run in reverse, or to be irreversible in the
+    /// entire. While it is recommended that such a migration throw an error (thus stopping any further progression
+    /// of the revert operation), there is no requirement that it do so. In practice, most irreversible migrations
+    /// choose to simply do nothing at all in this method. Implementors should carefully consider the consequences
+    /// of progressively older migrations attempting to revert themselves afterwards before leaving this method blank.
+    ///
+    /// - Parameter database: The database to revert.
+    func revert(on database: any SQLDatabase) async throws
+}
+
+extension AsyncSQLMigration {
+    // See `AsyncMigration.prepare(on:)`.
+    public func prepare(on database: any Database) async throws {
+        try await self.prepare(on: database as! any SQLDatabase)
+    }
+
+    // See `AsyncMigration.revert(on:)`.
+    public func revert(on database: any Database) async throws {
+        try await self.revert(on: database as! any SQLDatabase)
+    }
+}