Added plugin

Package.swift

@@ -12,6 +12,7 @@ let package = Package(
   products: [
     .executable(name: "rt", targets: ["ReleaseTools"]),
     .library(name: "Resources", targets: ["Resources"]),
+    .plugin(name: "ReleaseToolsPlugin", targets: ["ReleaseToolsPlugin"]),
   ],
 
   dependencies: [
@@ -20,7 +21,6 @@ let package = Package(
     .package(url: "https://github.com/elegantchaos/Logger.git", from: "1.6.0"),
     .package(url: "https://github.com/elegantchaos/Runner.git", from: "2.0.5"),
     .package(url: "https://github.com/elegantchaos/ChaosByteStreams", from: "1.0.0"),
-    .package(url: "https://github.com/elegantchaos/XCTestExtensions.git", from: "1.3.0"),
     .package(url: "https://github.com/elegantchaos/Versionator.git", from: "2.0.2"),
     .package(url: "https://github.com/apple/swift-argument-parser", from: "1.5.0"),
   ],
@@ -52,9 +52,26 @@ let package = Package(
       ]
     ),
 
+    .plugin(
+      name: "ReleaseToolsPlugin",
+      capability: .command(
+        intent: .custom(
+          verb: "rt",
+          description: "Manages archiving and uploading releases."
+        ),
+        permissions: [
+          .writeToPackageDirectory(reason: "Builds and archives releases.")
+        ]
+      ),
+
+      dependencies: [
+        "ReleaseTools"
+      ]
+    ),
+
     .testTarget(
       name: "ReleaseToolsTests",
-      dependencies: ["ReleaseTools", "XCTestExtensions"]
+      dependencies: ["ReleaseTools"]
     ),
   ]
 )

Plugins/ReleaseToolPlugin/ReleaseToolPlugin.swift

@@ -0,0 +1,44 @@
+// -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
+//  Created by Sam Deane on 03/09/24.
+//  All code (c) 2024 - present day, Elegant Chaos Limited.
+// -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
+
+import Foundation
+import PackagePlugin
+
+@main struct ReleaseToolsPlugin: CommandPlugin {
+  func run(tool: String, arguments: [String], context: PackagePlugin.PluginContext, cwd: URL) async throws -> String {
+    let tool = try context.tool(named: tool)
+
+    Diagnostics.remark("Running \(tool) \(arguments.joined(separator: " ")).")
+
+    let outputPipe = Pipe()
+    return try await withCheckedThrowingContinuation { continuation in
+      let process = Process()
+      process.executableURL = tool.url
+      process.arguments = arguments
+      process.currentDirectoryURL = cwd
+
+      process.standardOutput = outputPipe
+      process.terminationHandler = { process in
+        let data = outputPipe.fileHandleForReading.readDataToEndOfFile()
+        continuation.resume(
+          returning: String(decoding: data, as: UTF8.self)
+        )
+      }
+      do {
+        try process.run()
+      } catch {
+        continuation.resume(throwing: error)
+      }
+    }
+  }
+
+  func performCommand(context: PackagePlugin.PluginContext, arguments: [String]) async throws {
+    let output = try await run(
+      tool: "ActionBuilderTool", arguments: arguments, context: context, cwd: context.package.directoryURL)
+
+    Diagnostics.remark(output)
+
+  }
+}