Adding Tests (#5)

Package.swift

@@ -47,7 +47,8 @@ let package = Package(
       ]
     ),
     .testTarget(
-      name: "PackageDSLKitTests"
+      name: "PackageDSLKitTests",
+      dependencies: ["PackageDSLKit"]
     )
   ]
 )

Sources/PackageDSLKit/Component.swift

@@ -27,8 +27,8 @@
 //  OTHER DEALINGS IN THE SOFTWARE.
 //
 
-internal struct Component: Sendable, Hashable, Codable {
-  internal let name: String
-  internal let inheritedTypes: [String]
-  internal let properties: [String: Property]
+public struct Component: Sendable, Hashable, Codable {
+  public let name: String
+  public let inheritedTypes: [String]
+  public let properties: [String: Property]
 }

Sources/PackageDSLKit/ComponentWriter.swift

@@ -29,11 +29,18 @@
 
 import SwiftSyntax
 
-internal struct ComponentWriter: Sendable, Hashable, Codable {
-  private let propertyWriter = PropertyWriter()
-  internal func node(from component: Component) -> StructDeclSyntax {
+public struct ComponentWriter: Sendable, StructureWriter {
+  private let propertyWriter: @Sendable (Property) -> VariableDeclSyntax
+
+  public init(
+    propertyWriter: @escaping @Sendable (Property) -> VariableDeclSyntax = PropertyWriter.node
+  ) {
+    self.propertyWriter = propertyWriter
+  }
+
+  public func node(from component: Component) -> StructDeclSyntax {
     let memberBlockList = MemberBlockItemListSyntax(
-      component.properties.values.map(propertyWriter.node(from:)).map {
+      component.properties.values.map(propertyWriter).map {
         MemberBlockItemSyntax(decl: $0)
       }
     )

Sources/PackageDSLKit/Dependency.swift

@@ -40,18 +40,45 @@ public struct Dependency: TypeSource {
     public init(rawValue: Int) {
       self.rawValue = rawValue
     }
-    public init?(strings: [String]) {
+    internal struct InvalidValueError: Error {
+      internal init?(invalidCount: Int) {
+        guard invalidCount != 0 else {
+          return nil
+        }
+        assert(invalidCount > 0)
+        self.invalidCount = invalidCount
+      }
+
+      internal init?(valuesCount: Int, indiciesCount: Int) {
+        self.init(invalidCount: indiciesCount - valuesCount)
+      }
+
+      internal let invalidCount: Int
+    }
+    internal init?(stringsThrows strings: [String]) throws(InvalidValueError) {
       let indicies = strings.map {
         Self.strings.firstIndex(of: $0)
       }
       let rawValues = indicies.compactMap(\.self).map { $0 + 1 }
       if rawValues.isEmpty {
         return nil
       }
-      assert(rawValues.count == indicies.count)
+      if let error = InvalidValueError(valuesCount: rawValues.count, indiciesCount: indicies.count)
+      {
+        assert(error.invalidCount > 0)
+        throw error
+      }
       let rawValue = rawValues.reduce(0) { $0 + $1 }
       self.init(rawValue: rawValue)
     }
+    public init?(strings: [String]) {
+      do {
+        try self.init(stringsThrows: strings)
+      } catch {
+        assertionFailure("Invalid Values Passed: \(error.invalidCount)")
+        return nil
+      }
+    }
 
     internal func asInheritedTypes() -> [String] {
       rawValue.powerOfTwoExponents().map { Self.strings[$0] }

Sources/package/FileManager.swift → Sources/PackageDSLKit/FileManager.swift

@@ -28,11 +28,74 @@
 //
 
 import Foundation
-import PackageDSLKit
 
-@available(*, deprecated, message: "Migrate to separate protocol.")
-extension FileManager {
-  internal func swiftVersion(from directoryURL: URL) -> SwiftVersion? {
+extension FileManager: PackageFilesInterface {
+  public var currentDirectoryURL: URL {
+    URL(fileURLWithPath: currentDirectoryPath)
+  }
+
+  private func readDirectoryContents(at path: String, fileExtension: String = "swift") throws
+    -> [String]
+  {
+    var contents: [String] = []
+    let items = try contentsOfDirectory(atPath: path)
+
+    // Process subdirectories (post-order)
+    for item in items {
+      let itemPath = (path as NSString).appendingPathComponent(item)
+      var isDirectory: ObjCBool = false
+      let fileExists = fileExists(atPath: itemPath, isDirectory: &isDirectory)
+
+      if fileExists && isDirectory.boolValue {
+        contents += try readDirectoryContents(at: itemPath, fileExtension: fileExtension)
+      }
+    }
+
+    // Process files
+    for item in items where item.hasSuffix(".\(fileExtension)") {
+      let itemPath = (path as NSString).appendingPathComponent(item)
+
+      let fileContents = try String(contentsOfFile: itemPath, encoding: .utf8)
+      contents.append(fileContents)
+    }
+
+    return contents
+  }
+  public func writePackageSwiftFile(
+    swiftVersion: SwiftVersion,
+    from dslSourcesURL: URL,
+    to pathURL: URL
+  ) throws {
+    let contents = try self.readDirectoryContents(
+      at: dslSourcesURL.path(),
+      fileExtension: "swift"
+    )
+
+    let packageFileURL = pathURL.appendingPathComponent("Package.swift")
+    let strings =
+      [
+        "// swift-tools-version: \(swiftVersion)",
+        SupportCodeBlock.syntaxNode.trimmedDescription,
+      ] + contents
+    let data = Data(strings.joined(separator: "\n").utf8)
+    self.createFile(atPath: packageFileURL.path(), contents: data)
+    // TODO: log error if file creation fails
+  }
+
+  public func createDirectory(at url: URL, withIntermediateDirectories createIntermediates: Bool)
+    throws
+  {
+    try self.createDirectory(
+      at: url,
+      withIntermediateDirectories: createIntermediates,
+      attributes: nil
+    )
+  }
+
+  public func createFile(at url: URL, text: String) {
+    self.createFile(atPath: url.path(), contents: Data(text.utf8))
+  }
+  public func swiftVersion(from directoryURL: URL) -> SwiftVersion? {
     let swiftVersionURL = directoryURL.appending(component: ".swift-version")
     let packageSwiftURL = directoryURL.appending(component: "Package.swift")
 
@@ -53,7 +116,7 @@ extension FileManager {
 
     return .readFrom(packageSwiftFileURL: packageSwiftURL)
   }
-  internal func createTargetSourceAt(
+  public func createTargetSourceAt(
     _ pathURL: URL, productName: String, _ productType: ProductType
   ) throws {
     let sourcesDirURL = pathURL.appendingPathComponent("Sources/\(productName)")
@@ -82,27 +145,24 @@ extension FileManager {
       contents: Data(sourceCode.utf8)
     )
   }
-  internal func createTargetSourceAt(
-    _ pathURL: URL, productName: String, _ packageType: PackageType
+  public func createFileStructure(
+    forPackageType packageType: PackageType,
+    forProductName productName: String,
+    at pathURL: URL
   ) throws {
-    let productType: ProductType?
-
-    switch packageType {
-    case .empty:
-      productType = nil
-    case .library:
-      productType = .library
-    case .executable:
-      productType = .executable
+    guard packageType != .empty else {
+      return
     }
-    assert(productType != nil, "Unknown package type \(packageType)")
-    guard let productType else {
+
+    try self.createTargetSourceAt(pathURL, productName: productName, packageType)
+
+    guard packageType == .library else {
       return
     }
-    try self.createTargetSourceAt(pathURL, productName: productName, productType)
-  }
 
-  fileprivate func createTestTargetAt(_ pathURL: URL, _ productName: String) throws {
+    try createTestTargetAt(pathURL, productName)
+  }
+  private func createTestTargetAt(_ pathURL: URL, _ productName: String) throws {
     let testingDirURL = pathURL.appendingPathComponent("Tests/\(productName)Tests")
     try self.createDirectory(at: testingDirURL, withIntermediateDirectories: true)
 
@@ -117,68 +177,23 @@ extension FileManager {
       """
     self.createFile(atPath: testFileURL.path(), contents: Data(testCode.utf8))
   }
-
-  internal func createFileStructure(
-    forPackageType packageType: PackageType,
-    forProductName productName: String,
-    at pathURL: URL
-  ) throws {
-    guard packageType != .empty else {
-      return
-    }
-
-    try self.createTargetSourceAt(pathURL, productName: productName, packageType)
-
-    guard packageType == .library else {
-      return
-    }
-
-    try createTestTargetAt(pathURL, productName)
-  }
-  internal func writePackageSwiftFile(
-    swiftVersion: SwiftVersion,
-    from dslSourcesURL: URL,
-    to pathURL: URL
+  private func createTargetSourceAt(
+    _ pathURL: URL, productName: String, _ packageType: PackageType
   ) throws {
-    let contents = try self.readDirectoryContents(
-      at: dslSourcesURL.path(),
-      fileExtension: "swift"
-    )
-
-    let packageFileURL = pathURL.appendingPathComponent("Package.swift")
-    let strings =
-      [
-        "// swift-tools-version: \(swiftVersion)",
-        SupportCodeBlock.syntaxNode.trimmedDescription,
-      ] + contents
-    let data = Data(strings.joined(separator: "\n").utf8)
-    self.createFile(atPath: packageFileURL.path(), contents: data)
-  }
-  internal func readDirectoryContents(at path: String, fileExtension: String = "swift") throws
-    -> [String]
-  {
-    var contents: [String] = []
-    let items = try contentsOfDirectory(atPath: path)
-
-    // Process subdirectories (post-order)
-    for item in items {
-      let itemPath = (path as NSString).appendingPathComponent(item)
-      var isDirectory: ObjCBool = false
-      fileExists(atPath: itemPath, isDirectory: &isDirectory)
+    let productType: ProductType?
 
-      if isDirectory.boolValue {
-        contents += try readDirectoryContents(at: itemPath, fileExtension: fileExtension)
-      }
+    switch packageType {
+    case .empty:
+      productType = nil
+    case .library:
+      productType = .library
+    case .executable:
+      productType = .executable
     }
-
-    // Process files
-    for item in items where item.hasSuffix(".\(fileExtension)") {
-      let itemPath = (path as NSString).appendingPathComponent(item)
-
-      let fileContents = try String(contentsOfFile: itemPath, encoding: .utf8)
-      contents.append(fileContents)
+    assert(productType != nil, "Unknown package type \(packageType)")
+    guard let productType else {
+      return
     }
-
-    return contents
+    try self.createTargetSourceAt(pathURL, productName: productName, productType)
   }
 }

Sources/PackageDSLKit/IndexCodeWriter.swift

@@ -0,0 +1,34 @@
+//
+//  IndexCodeWriter.swift
+//  PackageDSLKit
+//
+//  Created by Leo Dion.
+//  Copyright © 2025 BrightDigit.
+//
+//  Permission is hereby granted, free of charge, to any person
+//  obtaining a copy of this software and associated documentation
+//  files (the “Software”), to deal in the Software without
+//  restriction, including without limitation the rights to use,
+//  copy, modify, merge, publish, distribute, sublicense, and/or
+//  sell copies of the Software, and to permit persons to whom the
+//  Software is furnished to do so, subject to the following
+//  conditions:
+//
+//  The above copyright notice and this permission notice shall be
+//  included in all copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND,
+//  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+//  OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+//  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+//  HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+//  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+//  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+//  OTHER DEALINGS IN THE SOFTWARE.
+//
+
+import SwiftSyntax
+
+public protocol IndexCodeWriter: Sendable {
+  func writeIndex(_ index: Index) throws(PackageDSLError) -> String
+}

Sources/PackageDSLKit/PackageFiles.swift

@@ -0,0 +1,51 @@
+//
+//  PackageFiles.swift
+//  PackageDSLKit
+//
+//  Created by Leo Dion.
+//  Copyright © 2025 BrightDigit.
+//
+//  Permission is hereby granted, free of charge, to any person
+//  obtaining a copy of this software and associated documentation
+//  files (the “Software”), to deal in the Software without
+//  restriction, including without limitation the rights to use,
+//  copy, modify, merge, publish, distribute, sublicense, and/or
+//  sell copies of the Software, and to permit persons to whom the
+//  Software is furnished to do so, subject to the following
+//  conditions:
+//
+//  The above copyright notice and this permission notice shall be
+//  included in all copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND,
+//  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+//  OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+//  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+//  HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+//  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+//  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+//  OTHER DEALINGS IN THE SOFTWARE.
+//
+
+import Foundation
+
+public struct PackageFiles: PackageFilesFactory {
+  public static let `default`: PackageFilesFactory = PackageFiles()
+
+  private static let defaultTypes:
+    [PackageFilesInterfaceType: @Sendable () -> any PackageFilesInterface] = [
+      .fileManager: { FileManager.default }
+    ]
+
+  private let types: [PackageFilesInterfaceType: @Sendable () -> any PackageFilesInterface]
+
+  internal init(
+    types: [PackageFilesInterfaceType: @Sendable () -> any PackageFilesInterface]? = nil
+  ) {
+    self.types = types ?? Self.defaultTypes
+  }
+
+  public func interface(for type: PackageFilesInterfaceType) -> any PackageFilesInterface {
+    self.types[type]!()
+  }
+}