feat: Add Wasm platform by conditionally building without swift-nio or async-kit

.github/workflows/test.yml

@@ -12,6 +12,8 @@ jobs:
       contents: read
     uses: vapor/ci/.github/workflows/run-unit-tests.yml@main
     secrets: inherit
+    with:
+      with_wasm: true
 
   # Make sure downstream dependents still work
   dependents-check:

Package.swift

@@ -1,6 +1,13 @@
 // swift-tools-version:5.8
 import PackageDescription
 
+/// `.when(platforms:)` can only include, never exclude, so excluding WASI means listing everything else.
+/// This list matches the [supported platforms on the Swift 5.8 release of SPM](https://github.com/swiftlang/swift-package-manager/blob/release/5.8/Sources/PackageDescription/SupportedPlatforms.swift);
+/// `.visionOS` arrived in SPM 5.9, and toolchains that know it read `Package@swift-5.9.swift` instead.
+/// Don't add new platforms here unless raising the swift-tools-version of this manifest.
+let allPlatforms: [Platform] = [.macOS, .macCatalyst, .iOS, .tvOS, .watchOS, .driverKit, .linux, .windows, .android, .wasi, .openbsd]
+let nonWASIPlatforms: [Platform] = allPlatforms.filter { $0 != .wasi }
+
 let package = Package(
     name: "sqlite-kit",
     platforms: [
@@ -22,8 +29,15 @@ let package = Package(
         .target(
             name: "SQLiteKit",
             dependencies: [
-                .product(name: "NIOFoundationCompat", package: "swift-nio"),
-                .product(name: "AsyncKit", package: "async-kit"),
+                // Target dependency conditions are evaluated per platform; on WASI these two
+                // products are not linked. AsyncKit's pool rides NIOPosix, which needs the POSIX
+                // sockets and threads WASI preview 1 lacks, and sqlite-nio's WASI flavor is
+                // SwiftNIO-free, so NIOFoundationCompat would have nothing to bridge and a linked
+                // NIOCore would flip the `#if canImport(NIOCore)` gates against a SQLiteNIO with no
+                // event loops. SQLiteKit then compiles without the connection pool and without the
+                // EventLoopFuture surface (see the `#if canImport(...)` gates in Sources/).
+                .product(name: "NIOFoundationCompat", package: "swift-nio", condition: .when(platforms: nonWASIPlatforms)),
+                .product(name: "AsyncKit", package: "async-kit", condition: .when(platforms: nonWASIPlatforms)),
                 .product(name: "SQLiteNIO", package: "sqlite-nio"),
                 .product(name: "SQLKit", package: "sql-kit"),
             ],

Package@swift-5.9.swift

@@ -1,6 +1,12 @@
 // swift-tools-version:5.9
 import PackageDescription
 
+/// `.when(platforms:)` can only include, never exclude, so excluding WASI means listing everything else.
+/// This list matches the [supported platforms on the Swift 5.9 release of SPM](https://github.com/swiftlang/swift-package-manager/blob/release/5.9/Sources/PackageDescription/SupportedPlatforms.swift).
+/// Don't add new platforms here unless raising the swift-tools-version of this manifest.
+let allPlatforms: [Platform] = [.macOS, .macCatalyst, .iOS, .tvOS, .watchOS, .visionOS, .driverKit, .linux, .windows, .android, .wasi, .openbsd]
+let nonWASIPlatforms: [Platform] = allPlatforms.filter { $0 != .wasi }
+
 let package = Package(
     name: "sqlite-kit",
     platforms: [
@@ -22,8 +28,15 @@ let package = Package(
         .target(
             name: "SQLiteKit",
             dependencies: [
-                .product(name: "NIOFoundationCompat", package: "swift-nio"),
-                .product(name: "AsyncKit", package: "async-kit"),
+                // Target dependency conditions are evaluated per platform; on WASI these two
+                // products are not linked. AsyncKit's pool rides NIOPosix, which needs the POSIX
+                // sockets and threads WASI preview 1 lacks, and sqlite-nio's WASI flavor is
+                // SwiftNIO-free, so NIOFoundationCompat would have nothing to bridge and a linked
+                // NIOCore would flip the `#if canImport(NIOCore)` gates against a SQLiteNIO with no
+                // event loops. SQLiteKit then compiles without the connection pool and without the
+                // EventLoopFuture surface (see the `#if canImport(...)` gates in Sources/).
+                .product(name: "NIOFoundationCompat", package: "swift-nio", condition: .when(platforms: nonWASIPlatforms)),
+                .product(name: "AsyncKit", package: "async-kit", condition: .when(platforms: nonWASIPlatforms)),
                 .product(name: "SQLiteNIO", package: "sqlite-nio"),
                 .product(name: "SQLKit", package: "sql-kit"),
             ],

Sources/SQLiteKit/Exports.swift

@@ -1,4 +1,7 @@
 @_documentation(visibility: internal) @_exported import SQLKit
 @_documentation(visibility: internal) @_exported import SQLiteNIO
+// AsyncKit, and with it the connection pool, is gated to the same platforms as SwiftNIO (see Package.swift).
+#if canImport(AsyncKit)
 @_documentation(visibility: internal) @_exported import AsyncKit
+#endif
 @_documentation(visibility: internal) @_exported import struct Logging.Logger

Sources/SQLiteKit/SQLiteConnection+SQLKit.swift

@@ -173,11 +173,13 @@ struct SQLiteDatabaseVersion: SQLDatabaseReportedVersion {
     @usableFromInline
     let decoder: SQLiteDataDecoder
 
+    #if canImport(NIOCore)
     // See `SQLDatabase.eventLoop`.
     @usableFromInline
     var eventLoop: any EventLoop {
         self.database.eventLoop
     }
+    #endif
 
     // See `SQLDatabase.version`.
     @usableFromInline
@@ -209,6 +211,9 @@ struct SQLiteDatabaseVersion: SQLDatabaseReportedVersion {
         self.queryLogLevel = queryLogLevel
     }
 
+    // The `EventLoopFuture` overload only exists where SwiftNIO does; SQLKit's protocol drops the
+    // requirement on the other platforms and the `async` overload below carries the whole surface.
+    #if canImport(NIOCore)
     // See `SQLDatabase.execute(sql:_:)`.
     @usableFromInline
     func execute(
@@ -234,6 +239,7 @@ struct SQLiteDatabaseVersion: SQLDatabaseReportedVersion {
             { onRow($0.sql(decoder: self.decoder)) }
         )
     }
+    #endif  // canImport(NIOCore)
 
     // See `SQLDatabase.execute(sql:_:)`.
     @usableFromInline

Sources/SQLiteKit/SQLiteConnectionSource.swift

@@ -1,3 +1,7 @@
+// ``SQLiteConnectionSource`` is a `ConnectionPoolSource`, built on AsyncKit and SwiftNIO's thread
+// pool. Neither is available on every platform SQLiteKit supports; where they are absent, callers
+// use sqlite-nio's concrete async `SQLiteConnection` directly and there is no pool.
+#if canImport(AsyncKit)
 #if canImport(Darwin)
 import Foundation
 #else
@@ -97,3 +101,4 @@ fileprivate extension SQLiteConfiguration.Storage {
         }
     }
 }
+#endif  // canImport(AsyncKit)

Sources/SQLiteKit/SQLiteDataDecoder.swift

@@ -1,7 +1,9 @@
 import Foundation
 import SQLiteNIO
 @_spi(CodableUtilities) import SQLKit
+#if canImport(NIOFoundationCompat)
 import NIOFoundationCompat
+#endif
 
 /// Translates `SQLiteData` values received from the database into `Decodable` values.
 ///
@@ -51,7 +53,15 @@ public struct SQLiteDataDecoder: Sendable {
 
                 switch data {
                 case .text(let str):  buf = .init(str.utf8)
+                // N.B.: `Data.init(buffer:byteTransferStrategy:)` is NIOFoundationCompat's
+                // zero-copy bridge and has no `[UInt8]` equivalent. The two cases stay forked
+                // rather than collapsing onto a copying spelling such as
+                // `Data(blob.readableBytesView)`, which would add a copy where SwiftNIO is present.
+                #if canImport(NIOFoundationCompat)
                 case .blob(let blob): buf = .init(buffer: blob, byteTransferStrategy: .noCopy)
+                #else
+                case .blob(let blob): buf = .init(blob)  // `SQLiteData.blob` carries `[UInt8]` without SwiftNIO
+                #endif
                 // The remaining cases should never happen, but we implement them anyway just in case.
                 case .integer(let n): buf = .init(String(n).utf8)
                 case .float(let n):   buf = .init(String(n).utf8)

Sources/SQLiteKit/SQLiteDataEncoder.swift

@@ -1,4 +1,3 @@
-import NIOCore
 import Foundation
 @_spi(CodableUtilities) import SQLKit
 import SQLiteNIO