feat: Moving things into separate modules.

Sources/FileClient/FileClient.swift

@@ -0,0 +1,138 @@
+import Dependencies
+import DependenciesMacros
+import Foundation
+
+public extension DependencyValues {
+
+  /// Access a basic ``FileClient`` that can read / write data to the file system.
+  ///
+  var fileClient: FileClient {
+    get { self[FileClient.self] }
+    set { self[FileClient.self] = newValue }
+  }
+}
+
+/// Represents the interactions with the file system.  It is able
+/// to read from and write to files.
+///
+///
+/// ```swift
+///  @Dependency(\.fileClient) var fileClient
+/// ```
+///
+@DependencyClient
+public struct FileClient: Sendable {
+
+  /// Return the current working directory.
+  public var currentDirectory: @Sendable () async throws -> String
+
+  /// Check if a file exists at the given url.
+  public var fileExists: @Sendable (URL) -> Bool = { _ in true }
+
+  /// Check if a url is a directory.
+  public var isDirectory: @Sendable (String) async throws -> Bool
+
+  /// Read the contents of a file.
+  public var read: @Sendable (URL) async throws -> String
+
+  /// Write `Data` to a file `URL`.
+  public var write: @Sendable (Data, URL) async throws -> Void
+
+  /// Read the contents of a file at the given path.
+  ///
+  /// - Parameters:
+  ///   - path: The file path to read from.
+  public func read(_ path: String) async throws -> String {
+    try await read(url(for: path))
+  }
+
+  /// Write's the the string to a  file path.
+  ///
+  /// - Parameters:
+  ///   - string: The string to write to the file.
+  ///   - path: The file path.
+  public func write(string: String, to path: String) async throws {
+    try await write(string: string, to: url(for: path))
+  }
+
+  /// Write's the the string to a  file path.
+  ///
+  /// - Parameters:
+  ///   - string: The string to write to the file.
+  ///   - url: The file url.
+  public func write(string: String, to url: URL) async throws {
+    try await write(Data(string.utf8), url)
+  }
+}
+
+extension FileClient: DependencyKey {
+
+  /// A ``FileClient`` that does not do anything.
+  public static let noop = FileClient(
+    currentDirectory: { "./" },
+    fileExists: { _ in true },
+    isDirectory: { _ in true },
+    read: { _ in "" },
+    write: { _, _ in }
+  )
+
+  /// An `unimplemented` ``FileClient``.
+  public static let testValue = FileClient()
+
+  /// The live ``FileClient``
+  public static let liveValue = FileClient(
+    currentDirectory: { FileManager.default.currentDirectoryPath },
+    fileExists: { FileManager.default.fileExists(atPath: $0.cleanFilePath) },
+    isDirectory: { path in
+      var isDirectory: ObjCBool = false
+      FileManager.default.fileExists(atPath: path, isDirectory: &isDirectory)
+      return isDirectory.boolValue
+    },
+    read: { try String(contentsOf: $0, encoding: .utf8) },
+    write: { try $0.write(to: $1, options: .atomic) }
+  )
+
+  public static func capturing(
+    _ captured: CapturingWrite
+  ) -> Self {
+    .init(
+      currentDirectory: { "./" },
+      fileExists: { _ in true },
+      isDirectory: { _ in true },
+      read: { _ in "" },
+      write: { await captured.set($0, $1) }
+    )
+  }
+
+}
+
+public actor CapturingWrite: Sendable {
+  public private(set) var data: Data?
+  public private(set) var url: URL?
+
+  public init() {}
+
+  func set(_ data: Data, _ url: URL) {
+    self.data = data
+    self.url = url
+  }
+}
+
+public extension URL {
+  var cleanFilePath: String {
+    absoluteString.replacingOccurrences(of: "file://", with: "")
+  }
+}
+
+public func url(for path: String) -> URL {
+  #if os(Linux)
+    return URL(fileURLWithPath: path)
+  #else
+    if #available(macOS 13.0, *) {
+      return URL(filePath: path)
+    } else {
+      // Fallback on earlier versions
+      return URL(fileURLWithPath: path)
+    }
+  #endif
+}