Allow relative path with swift package add-dependency command (#7871)

Enable passing relative path into `swift package add-dependency`

### Motivation:
Currently only `AbsolutePath`s are supported with `--type path` flag
```bash
swift package add-dependency /packagePath --type path
```
There is a need to support `RelativePath` because it's not uncommon to
have a package structure inside of an xcodeproj as shown below.

```bash
LocalPackages
├── ChildPackage
│   ├── .gitignore
│   ├── .swiftpm
│   ├── Package.swift
│   ├── Sources
│   └── Tests
└── ParentPackage
    ├── .build
    ├── .gitignore
    ├── .swiftpm
    ├── Package.swift
    ├── Sources
    └── Tests
```

If we want to open `ParentPackage` by itself, it will not be able to
resolve that package.


This pr allows for the user to add a package with a `RelativePath` path
via the `swift package add-dependency --type path` command.

Access level for 
- `.package(name:url:requirement:traits:)`
- `.package(name:url:requirement:)`
- `.package(id:requirement:traits:)`

were upgraded from `private` to `package` allowing access to these
functions from the `PackageCommands` module.

### Modifications:
- Enable passing relative path into `swift package add-dependency`
- Add unit test coverage

### Result:
Both of the following commands are valid

```bash
swift package add-dependency ../relative --type path
```

```bash
swift package add-dependency /absolute --type path
```

Author: hi2gage

Sources/Commands/PackageCommands/AddDependency.swift

@@ -66,24 +66,24 @@ extension SwiftPackageCommand {
                 throw StringError("unknown package")
             }
 
-            switch type {
+            switch self.type {
             case .url:
                 try self.createSourceControlPackage(
                     packagePath: packagePath,
                     workspace: workspace,
-                    url: dependency
+                    url: self.dependency
                 )
             case .path:
                 try self.createFileSystemPackage(
                     packagePath: packagePath,
                     workspace: workspace,
-                    directory: dependency
+                    directory: self.dependency
                 )
             case .registry:
                 try self.createRegistryPackage(
                     packagePath: packagePath,
                     workspace: workspace,
-                    id: dependency
+                    id: self.dependency
                 )
             }
         }
@@ -144,19 +144,10 @@ extension SwiftPackageCommand {
                 }
             }
 
-            let packageDependency: PackageDependency = .sourceControl(
-                identity: identity,
-                nameForTargetDependencyResolutionOnly: nil,
-                location: .remote(.init(url)),
-                requirement: requirement,
-                productFilter: .everything,
-                traits: []
-            )
-
-            try applyEdits(
+            try self.applyEdits(
                 packagePath: packagePath,
                 workspace: workspace,
-                packageDependency: packageDependency
+                packageDependency: .sourceControl(name: nil, location: url, requirement: requirement)
             )
         }
 
@@ -208,18 +199,10 @@ extension SwiftPackageCommand {
                 }
             }
 
-            let packageDependency: PackageDependency = .registry(
-                identity: identity,
-                requirement: requirement,
-                productFilter: .everything,
-                traits: []
-            )
-
-
-            try applyEdits(
+            try self.applyEdits(
                 packagePath: packagePath,
                 workspace: workspace,
-                packageDependency: packageDependency
+                packageDependency: .registry(id: id, requirement: requirement)
             )
         }
 
@@ -228,29 +211,17 @@ extension SwiftPackageCommand {
             workspace: Workspace,
             directory: String
         ) throws {
-            guard let path = try? Basics.AbsolutePath(validating: directory) else {
-                throw StringError("Package path not found")
-            }
-            let identity = PackageIdentity(path: path)
-            let packageDependency: PackageDependency = .fileSystem(
-                identity: identity,
-                nameForTargetDependencyResolutionOnly: nil,
-                path: path,
-                productFilter: .everything,
-                traits: []
-            )
-
-            try applyEdits(
+            try self.applyEdits(
                 packagePath: packagePath,
                 workspace: workspace,
-                packageDependency: packageDependency
+                packageDependency: .fileSystem(name: nil, path: directory)
             )
         }
 
         private func applyEdits(
             packagePath: Basics.AbsolutePath,
             workspace: Workspace,
-            packageDependency: PackageDependency
+            packageDependency: MappablePackageDependency.Kind
         ) throws {
             // Load the manifest file
             let fileSystem = workspace.fileSystem

Sources/PackageModelSyntax/AddPackageDependency.swift

@@ -18,7 +18,7 @@ import SwiftSyntax
 import SwiftSyntaxBuilder
 
 /// Add a package dependency to a manifest's source code.
-public struct AddPackageDependency {
+public enum AddPackageDependency {
     /// The set of argument labels that can occur after the "dependencies"
     /// argument in the Package initializers.
     ///
@@ -28,13 +28,13 @@ public struct AddPackageDependency {
         "targets",
         "swiftLanguageVersions",
         "cLanguageStandard",
-        "cxxLanguageStandard"
+        "cxxLanguageStandard",
     ]
 
     /// Produce the set of source edits needed to add the given package
     /// dependency to the given manifest file.
     public static func addPackageDependency(
-        _ dependency: PackageDependency,
+        _ dependency: MappablePackageDependency.Kind,
         to manifest: SourceFileSyntax
     ) throws -> PackageEditResult {
         // Make sure we have a suitable tools version in the manifest.
@@ -50,19 +50,19 @@ public struct AddPackageDependency {
 
         return PackageEditResult(
             manifestEdits: [
-                .replace(packageCall, with: newPackageCall.description)
+                .replace(packageCall, with: newPackageCall.description),
             ]
         )
     }
 
     /// Implementation of adding a package dependency to an existing call.
     static func addPackageDependencyLocal(
-        _ dependency: PackageDependency,
+        _ dependency: MappablePackageDependency.Kind,
         to packageCall: FunctionCallExprSyntax
     ) throws -> FunctionCallExprSyntax {
         try packageCall.appendingToArrayArgument(
             label: "dependencies",
-            trailingLabels: Self.argumentLabelsAfterDependencies,
+            trailingLabels: self.argumentLabelsAfterDependencies,
             newElement: dependency.asSyntax()
         )
     }

Sources/PackageModelSyntax/AddTarget.swift

@@ -18,7 +18,7 @@ import SwiftSyntaxBuilder
 import struct TSCUtility.Version
 
 /// Add a target to a manifest's source code.
-public struct AddTarget {
+public enum AddTarget {
     /// The set of argument labels that can occur after the "targets"
     /// argument in the Package initializers.
     ///
@@ -27,7 +27,7 @@ public struct AddTarget {
     private static let argumentLabelsAfterTargets: Set<String> = [
         "swiftLanguageVersions",
         "cLanguageStandard",
-        "cxxLanguageStandard"
+        "cxxLanguageStandard",
     ]
 
     /// The kind of test harness to use. This isn't part of the manifest
@@ -85,7 +85,7 @@ public struct AddTarget {
             target.dependencies.append(contentsOf: macroTargetDependencies)
 
         default:
-            break;
+            break
         }
 
         var newPackageCall = try packageCall.appendingToArrayArgument(
@@ -103,7 +103,7 @@ public struct AddTarget {
         guard let outerDirectory else {
             return PackageEditResult(
                 manifestEdits: [
-                    .replace(packageCall, with: newPackageCall.description)
+                    .replace(packageCall, with: newPackageCall.description),
                 ]
             )
         }
@@ -114,7 +114,7 @@ public struct AddTarget {
         var auxiliaryFiles: AuxiliaryFiles = []
 
         // Add the primary source file. Every target type has this.
-        addPrimarySourceFile(
+        self.addPrimarySourceFile(
             outerPath: outerPath,
             target: target,
             configuration: configuration,
@@ -125,7 +125,7 @@ public struct AddTarget {
         var extraManifestEdits: [SourceEdit] = []
         switch target.type {
         case .macro:
-            addProvidedMacrosSourceFile(
+            self.addProvidedMacrosSourceFile(
                 outerPath: outerPath,
                 target: target,
                 to: &auxiliaryFiles
@@ -135,7 +135,7 @@ public struct AddTarget {
                 newPackageCall = try AddPackageDependency
                     .addPackageDependencyLocal(
                         .swiftSyntax(
-                          configuration: installedSwiftPMConfiguration
+                            configuration: installedSwiftPMConfiguration
                         ),
                         to: newPackageCall
                     )
@@ -149,7 +149,7 @@ public struct AddTarget {
                             .positionAfterSkippingLeadingTrivia
                         extraManifestEdits.append(
                             SourceEdit(
-                                range: insertPos..<insertPos,
+                                range: insertPos ..< insertPos,
                                 replacement: newImport
                             )
                         )
@@ -158,12 +158,12 @@ public struct AddTarget {
                 }
             }
 
-        default: break;
+        default: break
         }
 
         return PackageEditResult(
             manifestEdits: [
-                .replace(packageCall, with: newPackageCall.description)
+                .replace(packageCall, with: newPackageCall.description),
             ] + extraManifestEdits,
             auxiliaryFiles: auxiliaryFiles
         )
@@ -182,20 +182,18 @@ public struct AddTarget {
         )
 
         // Introduce imports for each of the dependencies that were specified.
-        var importModuleNames = target.dependencies.map {
-            $0.name
-        }
+        var importModuleNames = target.dependencies.map(\.name)
 
         // Add appropriate test module dependencies.
         if target.type == .test {
             switch configuration.testHarness {
-            case .none: 
+            case .none:
                 break
 
             case .xctest:
                 importModuleNames.append("XCTest")
 
-            case .swiftTesting: 
+            case .swiftTesting:
                 importModuleNames.append("Testing")
             }
         }
@@ -306,25 +304,25 @@ public struct AddTarget {
     }
 }
 
-fileprivate extension TargetDescription.Dependency {
+extension TargetDescription.Dependency {
     /// Retrieve the name of the dependency
-    var name: String {
+    fileprivate var name: String {
         switch self {
         case .target(name: let name, condition: _),
-            .byName(name: let name, condition: _),
-            .product(name: let name, package: _, moduleAliases: _, condition: _):
+             .byName(name: let name, condition: _),
+             .product(name: let name, package: _, moduleAliases: _, condition: _):
             name
         }
     }
 }
 
 /// The array of auxiliary files that can be added by a package editing
 /// operation.
-fileprivate typealias AuxiliaryFiles = [(RelativePath, SourceFileSyntax)]
+private typealias AuxiliaryFiles = [(RelativePath, SourceFileSyntax)]
 
-fileprivate extension AuxiliaryFiles {
+extension AuxiliaryFiles {
     /// Add a source file to the list of auxiliary files.
-    mutating func addSourceFile(
+    fileprivate mutating func addSourceFile(
         path: RelativePath,
         sourceCode: SourceFileSyntax
     ) {
@@ -334,45 +332,42 @@ fileprivate extension AuxiliaryFiles {
 
 /// The set of dependencies we need to introduce to a newly-created macro
 /// target.
-fileprivate let macroTargetDependencies: [TargetDescription.Dependency] = [
+private let macroTargetDependencies: [TargetDescription.Dependency] = [
     .product(name: "SwiftCompilerPlugin", package: "swift-syntax"),
     .product(name: "SwiftSyntaxMacros", package: "swift-syntax"),
 ]
 
 /// The package dependency for swift-syntax, for use in macros.
-fileprivate extension PackageDependency {
+extension MappablePackageDependency.Kind {
     /// Source control URL for the swift-syntax package.
-    static var swiftSyntaxURL: SourceControlURL {
+    fileprivate static var swiftSyntaxURL: SourceControlURL {
         "https://github.com/swiftlang/swift-syntax.git"
     }
 
     /// Package dependency on the swift-syntax package.
-    static func swiftSyntax(
-      configuration: InstalledSwiftPMConfiguration
-    ) -> PackageDependency {
+    fileprivate static func swiftSyntax(
+        configuration: InstalledSwiftPMConfiguration
+    ) -> MappablePackageDependency.Kind {
         let swiftSyntaxVersionDefault = configuration
             .swiftSyntaxVersionForMacroTemplate
         let swiftSyntaxVersion = Version(swiftSyntaxVersionDefault.description)!
 
         return .sourceControl(
-            identity: PackageIdentity(url: swiftSyntaxURL),
-            nameForTargetDependencyResolutionOnly: nil,
-            location: .remote(swiftSyntaxURL),
-            requirement: .range(.upToNextMajor(from: swiftSyntaxVersion)),
-            productFilter: .everything,
-            traits: []
+            name: nil,
+            location: self.swiftSyntaxURL.absoluteString,
+            requirement: .range(.upToNextMajor(from: swiftSyntaxVersion))
         )
     }
 }
 
-fileprivate extension TargetDescription {
-    var sanitizedName: String {
-        name
+extension TargetDescription {
+    fileprivate var sanitizedName: String {
+        self.name
             .spm_mangledToC99ExtendedIdentifier()
             .localizedFirstWordCapitalized()
     }
 }
 
-fileprivate extension String {
-    func localizedFirstWordCapitalized() -> String { prefix(1).localizedCapitalized + dropFirst() }
+extension String {
+    fileprivate func localizedFirstWordCapitalized() -> String { prefix(1).localizedCapitalized + dropFirst() }
 }