Rename the package name property in the plugin APIs to displayName, as the evolution proposal says. Also pass in the package identity, and use that as the Package.id in the plugin-visible API. (#3854)

Author: abertelrud

Sources/PackagePlugin/PackageModel.swift

@@ -15,7 +15,7 @@ public struct Package {
     public typealias ID = String
 
     /// The name of the package (for display purposes only).
-    public let name: String
+    public let displayName: String
 
     /// The absolute path of the package directory in the local file system.
     public let directory: Path

Sources/PackagePlugin/PluginInput.swift

@@ -264,8 +264,8 @@ fileprivate struct PluginInputDeserializer {
         let products = try wirePackage.productIds.map { try self.product(for: $0) }
         let targets = try wirePackage.targetIds.map { try self.target(for: $0) }
         let package = Package(
-            id: String(id),
-            name: wirePackage.name,
+            id: wirePackage.identity,
+            displayName: wirePackage.displayName,
             directory: directory,
             origin: .root,
             toolsVersion: toolsVersion,
@@ -312,7 +312,8 @@ fileprivate struct WireInput: Decodable {
     /// their ID numbers.
     struct Package: Decodable {
         typealias Id = Int
-        let name: String
+        let identity: String
+        let displayName: String
         let directoryId: Path.Id
         let origin: Origin
         let toolsVersion: ToolsVersion

Sources/PackagePlugin/Protocols.swift

@@ -72,4 +72,12 @@ extension BuildToolPlugin {
             builtProductsDirectory: context.builtProductsDirectory,
             toolNamesToPaths: context.toolNamesToPaths))
     }
+
+    /// Default implementation that does nothing.
+    public func createBuildCommands(
+        context: TargetBuildContext
+    ) throws -> [Command] {
+        return []
+    }
 }
+

Sources/SPMBuildCore/PluginInvocation.swift

@@ -395,7 +395,8 @@ struct PluginScriptRunnerInput: Codable {
     /// their ID numbers.
     struct Package: Codable {
         typealias Id = Int
-        let name: String
+        let identity: String
+        let displayName: String
         let directoryId: Path.Id
         let origin: Origin
         let toolsVersion: ToolsVersion
@@ -790,8 +791,8 @@ struct PluginScriptRunnerInputSerializer {
         // Assign the next wire ID to the package and append a serialized Package record.
         let id = packages.count
         packages.append(.init(
-            // FIXME: can we use package identity instead?
-            name: package.manifest.displayName,
+            identity: package.identity.description,
+            displayName: package.manifest.displayName,
             directoryId: try serialize(path: package.path),
             origin: try origin(for: package),
             toolsVersion: .init(

Tests/CommandsTests/PackageToolTests.swift

@@ -1039,6 +1039,67 @@ final class PackageToolTests: CommandsTestCase {
       #endif
     }
 
+    func testBuildToolPlugin() throws {
+        
+        try testWithTemporaryDirectory { tmpPath in
+            // Create a sample package with a library target and a plugin.
+            let packageDir = tmpPath.appending(components: "MyPackage")
+            try localFileSystem.writeFileContents(packageDir.appending(component: "Package.swift")) {
+                $0 <<< """
+                // swift-tools-version: 999.0
+                import PackageDescription
+                let package = Package(
+                    name: "MyPackage",
+                    targets: [
+                        .target(
+                            name: "MyLibrary",
+                            plugins: [
+                                "MyPlugin",
+                            ]
+                        ),
+                        .plugin(
+                            name: "MyPlugin",
+                            capability: .buildTool()
+                        ),
+                    ]
+                )
+                """
+            }
+            try localFileSystem.writeFileContents(packageDir.appending(components: "Sources", "MyLibrary", "library.swift")) {
+                $0 <<< """
+                    public func Foo() { }
+                """
+            }
+            try localFileSystem.writeFileContents(packageDir.appending(components: "Plugins", "MyPlugin", "plugin.swift")) {
+                $0 <<< """
+                    import PackagePlugin
+                    
+                    @main
+                    struct MyBuildToolPlugin: BuildToolPlugin {
+                        func createBuildCommands(
+                            context: PluginContext,
+                            target: Target
+                        ) throws -> [Command] {
+                            guard context.package.displayName == "MyPackage" else {
+                                throw Error.inconsistentDisplayName(context.package.displayName)
+                            }
+                            return []
+                        }
+
+                        enum Error : Swift.Error {
+                        case inconsistentDisplayName(String)
+                        }
+                    }
+                """
+            }
+            
+            // Invoke it, and check the results.
+            let result = try SwiftPMProduct.SwiftBuild.executeProcess([], packagePath: packageDir)
+            XCTAssertEqual(result.exitStatus, .terminated(code: 0))
+            XCTAssert(try result.utf8Output().contains("Build complete!"))
+        }
+    }
+
     func testArchiveSource() throws {
         fixture(name: "DependencyResolution/External/Simple") { prefix in
             let packageRoot = prefix.appending(component: "Bar")