feat: Breaking out more dependencies.

Sources/FileClient/FileClient.swift

@@ -0,0 +1,63 @@
+import Dependencies
+import DependenciesMacros
+import Foundation
+
+public extension DependencyValues {
+  var fileClient: FileClient {
+    get { self[FileClient.self] }
+    set { self[FileClient.self] = newValue }
+  }
+}
+
+@DependencyClient
+public struct FileClient: Sendable {
+  public var copy: @Sendable (URL, URL) async throws -> Void
+  public var fileExists: @Sendable (URL) -> Bool = { _ in true }
+  public var homeDirectory: @Sendable () -> URL = { URL(filePath: "~/") }
+  public var load: @Sendable (URL) async throws -> Data
+  public var write: @Sendable (Data, URL) async throws -> Void
+}
+
+extension FileClient: DependencyKey {
+  public static let testValue: FileClient = Self()
+
+  public static var liveValue: Self {
+    let manager = LiveFileClient()
+    return .init {
+      try await manager.copy($0, to: $1)
+    } fileExists: { url in
+      manager.fileExists(at: url)
+    } homeDirectory: {
+      manager.homeDirectory()
+    } load: { url in
+      try await manager.load(from: url)
+    } write: { data, url in
+      try await manager.write(data, to: url)
+    }
+  }
+}
+
+struct LiveFileClient: Sendable {
+
+  private var manager: FileManager { FileManager.default }
+
+  func copy(_ url: URL, to toUrl: URL) async throws {
+    try manager.copyItem(at: url, to: toUrl)
+  }
+
+  func fileExists(at url: URL) -> Bool {
+    manager.fileExists(atPath: url.absoluteString.replacing("file://", with: ""))
+  }
+
+  func homeDirectory() -> URL {
+    manager.homeDirectoryForCurrentUser
+  }
+
+  func load(from url: URL) async throws -> Data {
+    try Data(contentsOf: url)
+  }
+
+  func write(_ data: Data, to url: URL) async throws {
+    try data.write(to: url)
+  }
+}