Port "Add target dependency" package manifest editing action to SwiftRefactor

This manifest editing action introduces a new dependency to an existing target

Author: DougGregor

Sources/SwiftRefactor/CMakeLists.txt

@@ -24,6 +24,7 @@ add_swift_syntax_library(SwiftRefactor
 
   PackageManifest/AbsolutePath.swift
   PackageManifest/AddPackageDependency.swift
+  PackageManifest/AddTargetDependency.swift
   PackageManifest/ManifestEditError.swift
   PackageManifest/ManifestEditRefactoringProvider.swift
   PackageManifest/ManifestSyntaxRepresentable.swift
@@ -34,6 +35,7 @@ add_swift_syntax_library(SwiftRefactor
   PackageManifest/SemanticVersion.swift
   PackageManifest/SourceControlURL.swift
   PackageManifest/SyntaxEditUtils.swift
+  PackageManifest/TargetDescription.swift
 )
 
 target_link_swift_syntax_libraries(SwiftRefactor PUBLIC

Sources/SwiftRefactor/PackageManifest/AddTargetDependency.swift

@@ -0,0 +1,114 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift open source project
+//
+// Copyright (c) 2024 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See http://swift.org/LICENSE.txt for license information
+// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import SwiftParser
+import SwiftSyntax
+import SwiftSyntaxBuilder
+
+/// Add a target dependency to a manifest's source code.
+public struct AddTargetDependency: ManifestEditRefactoringProvider {
+  public struct Context {
+    /// The dependency to add.
+    public var dependency: TargetDescription.Dependency
+
+    /// The name of the target to which the dependency will be added.
+    public var targetName: String
+
+    public init(dependency: TargetDescription.Dependency, targetName: String) {
+      self.dependency = dependency
+      self.targetName = targetName
+    }
+  }
+
+  /// The set of argument labels that can occur after the "dependencies"
+  /// argument in the various target initializers.
+  ///
+  /// TODO: Could we generate this from the the PackageDescription module, so
+  /// we don't have keep it up-to-date manually?
+  private static let argumentLabelsAfterDependencies: Set<String> = [
+    "path",
+    "exclude",
+    "sources",
+    "resources",
+    "publicHeadersPath",
+    "packageAccess",
+    "cSettings",
+    "cxxSettings",
+    "swiftSettings",
+    "linkerSettings",
+    "plugins",
+  ]
+
+  /// Produce the set of source edits needed to add the given target
+  /// dependency to the given manifest file.
+  public static func manifestRefactor(
+    syntax manifest: SourceFileSyntax,
+    in context: Context
+  ) throws -> PackageEditResult {
+    let dependency = context.dependency
+    let targetName = context.targetName
+
+    guard let packageCall = manifest.findCall(calleeName: "Package") else {
+      throw ManifestEditError.cannotFindPackage
+    }
+
+    // Dig out the array of targets.
+    guard let targetsArgument = packageCall.findArgument(labeled: "targets"),
+      let targetArray = targetsArgument.expression.findArrayArgument()
+    else {
+      throw ManifestEditError.cannotFindTargets
+    }
+
+    // Look for a call whose name is a string literal matching the
+    // requested target name.
+    func matchesTargetCall(call: FunctionCallExprSyntax) -> Bool {
+      guard let nameArgument = call.findArgument(labeled: "name") else {
+        return false
+      }
+
+      guard let stringLiteral = nameArgument.expression.as(StringLiteralExprSyntax.self),
+        let literalValue = stringLiteral.representedLiteralValue
+      else {
+        return false
+      }
+
+      return literalValue == targetName
+    }
+
+    guard let targetCall = FunctionCallExprSyntax.findFirst(in: targetArray, matching: matchesTargetCall) else {
+      throw ManifestEditError.cannotFindTarget(targetName: targetName)
+    }
+
+    let newTargetCall = try addTargetDependencyLocal(
+      dependency,
+      to: targetCall
+    )
+
+    return PackageEditResult(
+      manifestEdits: [
+        .replace(targetCall, with: newTargetCall.description)
+      ]
+    )
+  }
+
+  /// Implementation of adding a target dependency to an existing call.
+  static func addTargetDependencyLocal(
+    _ dependency: TargetDescription.Dependency,
+    to targetCall: FunctionCallExprSyntax
+  ) throws -> FunctionCallExprSyntax {
+    try targetCall.appendingToArrayArgument(
+      label: "dependencies",
+      trailingLabels: Self.argumentLabelsAfterDependencies,
+      newElement: dependency.asSyntax()
+    )
+  }
+}

Sources/SwiftRefactor/PackageManifest/TargetDescription.swift

@@ -0,0 +1,39 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift open source project
+//
+// Copyright (c) 2024 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See http://swift.org/LICENSE.txt for license information
+// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import SwiftSyntax
+
+/// Syntactic wrapper type that describes a target for refactoring
+/// purposes but does not interpret its contents.
+public struct TargetDescription {
+  public let name: String
+
+  public enum Dependency {
+    case target(name: String)
+    case product(name: String, package: String?)
+  }
+}
+
+extension TargetDescription.Dependency: ManifestSyntaxRepresentable {
+  func asSyntax() -> ExprSyntax {
+    switch self {
+    case .target(name: let name):
+      ".target(name: \(literal: name))"
+
+    case .product(name: let name, package: nil):
+      ".product(name: \(literal: name))"
+
+    case .product(name: let name, package: let package):
+      ".product(name: \(literal: name), package: \(literal: package))"
+    }
+  }
+}

Tests/SwiftRefactorTest/ManifestEditTests.swift

@@ -281,6 +281,48 @@ final class ManifestEditTests: XCTestCase {
       }
     }
   }
+
+  func testAddTargetDependency() throws {
+    try assertManifestRefactor(
+      """
+      // swift-tools-version: 5.5
+      let package = Package(
+          name: "packages",
+          dependencies: [
+              .package(url: "https://github.com/swiftlang/swift-example.git", from: "1.2.3"),
+          ],
+          targets: [
+              .testTarget(
+                  name: "MyTest"
+              ),
+          ]
+      )
+      """,
+      expectedManifest: """
+        // swift-tools-version: 5.5
+        let package = Package(
+            name: "packages",
+            dependencies: [
+                .package(url: "https://github.com/swiftlang/swift-example.git", from: "1.2.3"),
+            ],
+            targets: [
+                .testTarget(
+                    name: "MyTest",
+                    dependencies: [
+                        .product(name: "SomethingOrOther", package: "swift-example"),
+                    ]
+                ),
+            ]
+        )
+        """,
+      provider: AddTargetDependency.self,
+      context: .init(
+        dependency: .product(name: "SomethingOrOther", package: "swift-example"),
+        targetName: "MyTest"
+      )
+    )
+  }
+
 }
 
 /// Assert that applying the given edit/refactor operation to the manifest