Swift package manifest refactoring actions

Package.swift

@@ -393,7 +393,7 @@ let package = Package(
 
     .testTarget(
       name: "SwiftRefactorTest",
-      dependencies: ["_SwiftSyntaxTestSupport", "SwiftRefactor"]
+      dependencies: ["_SwiftSyntaxTestSupport", "SwiftIDEUtils", "SwiftRefactor"]
     ),
 
     // MARK: - Deprecated targets

Sources/SwiftRefactor/CMakeLists.txt

@@ -22,6 +22,22 @@ add_swift_syntax_library(SwiftRefactor
   RefactoringProvider.swift
   RemoveSeparatorsFromIntegerLiteral.swift
   SyntaxUtils.swift
+
+  PackageManifest/AddPackageDependency.swift
+  PackageManifest/AddPackageTarget.swift
+  PackageManifest/AddPluginUsage.swift
+  PackageManifest/AddProduct.swift
+  PackageManifest/AddSwiftSetting.swift
+  PackageManifest/AddTargetDependency.swift
+  PackageManifest/ManifestEditError.swift
+  PackageManifest/ManifestEditRefactoringProvider.swift
+  PackageManifest/ManifestSyntaxRepresentable.swift
+  PackageManifest/PackageDependency.swift
+  PackageManifest/PackageEdit.swift
+  PackageManifest/PackageTarget.swift
+  PackageManifest/ProductDescription.swift
+  PackageManifest/StringUtils.swift
+  PackageManifest/SyntaxEditUtils.swift
 )
 
 target_link_swift_syntax_libraries(SwiftRefactor PUBLIC

Sources/SwiftRefactor/PackageManifest/AddPackageDependency.swift

@@ -0,0 +1,138 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2025 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import SwiftParser
+import SwiftSyntax
+import SwiftSyntaxBuilder
+
+/// Add a package dependency to a package manifest's source code.
+public struct AddPackageDependency: ManifestEditRefactoringProvider {
+  public struct Context {
+    public var dependency: PackageDependency
+
+    public init(dependency: PackageDependency) {
+      self.dependency = dependency
+    }
+  }
+
+  /// The set of argument labels that can occur after the "dependencies"
+  /// argument in the Package initializers.
+  private static let argumentLabelsAfterDependencies: Set<String> = [
+    "targets",
+    "swiftLanguageVersions",
+    "cLanguageStandard",
+    "cxxLanguageStandard",
+  ]
+
+  /// Produce the set of source edits needed to add the given package
+  /// dependency to the given manifest file.
+  public static func manifestRefactor(
+    syntax manifest: SourceFileSyntax,
+    in context: Context
+  ) throws -> PackageEdit {
+    let dependency = context.dependency
+    guard let packageCall = manifest.findCall(calleeName: "Package") else {
+      throw ManifestEditError.cannotFindPackage
+    }
+
+    guard
+      try !dependencyAlreadyAdded(
+        dependency,
+        in: packageCall
+      )
+    else {
+      return PackageEdit(manifestEdits: [])
+    }
+
+    let newPackageCall = try addPackageDependencyLocal(
+      dependency,
+      to: packageCall
+    )
+
+    return PackageEdit(
+      manifestEdits: [
+        .replace(packageCall, with: newPackageCall.description)
+      ]
+    )
+  }
+
+  /// Return `true` if the dependency already exists in the manifest, otherwise return `false`.
+  /// Throws an error if a dependency already exists with the same id or url, but different arguments.
+  private static func dependencyAlreadyAdded(
+    _ dependency: PackageDependency,
+    in packageCall: FunctionCallExprSyntax
+  ) throws -> Bool {
+    let dependencySyntax = dependency.asSyntax()
+    guard let dependencyFnSyntax = dependencySyntax.as(FunctionCallExprSyntax.self) else {
+      throw ManifestEditError.cannotFindPackage
+    }
+
+    guard
+      let id = dependencyFnSyntax.arguments.first(where: {
+        $0.label?.text == "url" || $0.label?.text == "id" || $0.label?.text == "path"
+      })
+    else {
+      throw ManifestEditError.malformedManifest(error: "missing id or url argument in dependency syntax")
+    }
+
+    if let existingDependencies = packageCall.findArgument(labeled: "dependencies") {
+      // If we have an existing dependencies array, we need to check if
+      if let expr = existingDependencies.expression.as(ArrayExprSyntax.self) {
+        // Iterate through existing dependencies and look for an argument that matches
+        // either the `id` or `url` argument of the new dependency.
+        let existingArgument = expr.elements.first { elem in
+          if let funcExpr = elem.expression.as(FunctionCallExprSyntax.self) {
+            return funcExpr.arguments.contains {
+              $0.trimmedDescription == id.trimmedDescription
+            }
+          }
+          return true
+        }
+
+        if let existingArgument {
+          let normalizedExistingArgument = existingArgument.detached.with(\.trailingComma, nil)
+          // This exact dependency already exists, return false to indicate we should do nothing.
+          if normalizedExistingArgument.trimmedDescription == dependencySyntax.trimmedDescription {
+            return true
+          }
+          throw ManifestEditError.existingDependency(dependencyName: dependency.identifier)
+        }
+      }
+    }
+    return false
+  }
+
+  /// Implementation of adding a package dependency to an existing call.
+  static func addPackageDependencyLocal(
+    _ dependency: PackageDependency,
+    to packageCall: FunctionCallExprSyntax
+  ) throws -> FunctionCallExprSyntax {
+    try packageCall.appendingToArrayArgument(
+      label: "dependencies",
+      labelsAfter: Self.argumentLabelsAfterDependencies,
+      newElement: dependency.asSyntax()
+    )
+  }
+}
+
+fileprivate extension PackageDependency {
+  var identifier: String {
+    switch self {
+    case .sourceControl(let info):
+      return info.identity
+    case .fileSystem(let info):
+      return info.identity
+    case .registry(let info):
+      return info.identity
+    }
+  }
+}