add support for loading images from the local file system

Sources/NetworkImage/NetworkImageLoader.swift

@@ -18,7 +18,7 @@ public actor DefaultNetworkImageLoader {
     static let timeoutInterval: TimeInterval = 15
   }
 
-  private let data: (URL) async throws -> (Data, URLResponse)
+  private let data: @Sendable (URL) async throws -> (Data, URLResponse)
   private let cache: NetworkImageCache
 
   private var ongoingTasks: [URL: Task<CGImage, Error>] = [:]
@@ -47,7 +47,7 @@ public actor DefaultNetworkImageLoader {
 
   init(
     cache: NetworkImageCache,
-    data: @escaping (URL) async throws -> (Data, URLResponse)
+    data: @escaping @Sendable (URL) async throws -> (Data, URLResponse)
   ) {
     self.data = data
     self.cache = cache
@@ -70,9 +70,7 @@ extension DefaultNetworkImageLoader: NetworkImageLoader {
       // remove ongoing task
       self.ongoingTasks.removeValue(forKey: url)
 
-      guard let statusCode = (response as? HTTPURLResponse)?.statusCode,
-        200..<300 ~= statusCode
-      else {
+      if let response = response as? HTTPURLResponse, !(200..<300).contains(response.statusCode) {
         throw URLError(.badServerResponse)
       }
 

Tests/NetworkImageTests/DefaultNetworkImageLoaderTests.swift

@@ -1,15 +1,23 @@
 import XCTest
 
 @testable import NetworkImage
+#if canImport(AppKit)
+import class AppKit.NSImage
+#elseif canImport(UIKit)
+import class UIKit.UIImage
+#endif
 
 final class DefaultNetworkImageLoaderTests: XCTestCase {
+  @MainActor
   func testImageLoad() async throws {
     // given
     let imageCache = DefaultNetworkImageCache()
 
     var loadCount = 0
     let imageLoader = DefaultNetworkImageLoader(cache: imageCache) { _ in
-      loadCount += 1
+      Task { @MainActor in
+        loadCount += 1
+      }
       return (Fixtures.imageData, Fixtures.okResponse)
     }
 
@@ -27,14 +35,17 @@ final class DefaultNetworkImageLoaderTests: XCTestCase {
     XCTAssertIdentical(imageCache.image(for: Fixtures.anotherURL), images.1)
   }
 
+  @MainActor
   func testImageCache() async throws {
     // given
     let imageCache = DefaultNetworkImageCache()
     imageCache.setImage(Fixtures.image, for: Fixtures.url)
 
     var loadCount = 0
     let imageLoader = DefaultNetworkImageLoader(cache: imageCache) { _ in
-      loadCount += 1
+      Task { @MainActor in
+        loadCount += 1
+      }
       return (Fixtures.imageData, Fixtures.okResponse)
     }
 
@@ -83,4 +94,36 @@ final class DefaultNetworkImageLoaderTests: XCTestCase {
     // then
     XCTAssertEqual(capturedError, URLError(.cannotDecodeContentData))
   }
+
+  func testLocalImageLoading() async throws {
+    // given
+    let fileManager = FileManager.default
+    let tmpDir = fileManager.temporaryDirectory.appendingPathComponent(UUID().uuidString)
+    try fileManager.createDirectory(at: tmpDir, withIntermediateDirectories: true)
+    defer {
+      try? fileManager.removeItem(at: tmpDir)
+    }
+    let localImageUrl = tmpDir.appendingPathComponent("image", conformingTo: .png)
+    try Fixtures.imageData.write(to: localImageUrl)
+    let imageLoader = DefaultNetworkImageLoader.shared
+
+    // when
+    let image = try await imageLoader.image(from: localImageUrl)
+
+    // then
+    try XCTAssertEqual(XCTUnwrap(image.pngData), XCTUnwrap(Fixtures.image.pngData))
+  }
+}
+
+
+// MARK: Utils
+
+extension CGImage {
+  var pngData: Data? {
+  #if canImport(AppKit)
+    NSBitmapImageRep(cgImage: self).representation(using: .png, properties: [:])
+  #elseif canImport(UIKit)
+    UIImage(cgImage: self).pngData()
+  #endif
+  }
 }