Fix an issue with scale and coalesing

Sources/Nuke/Internal/ImageRequestKeys.swift

@@ -40,23 +40,26 @@ extension ImageRequest {
 final class CacheKey: Hashable, Sendable {
     // Using a reference type turned out to be significantly faster
     private let imageId: String?
+    private let scale: Float
     private let thumbnail: ImageRequest.ThumbnailOptions?
     private let processors: [any ImageProcessing]
 
     init(_ request: ImageRequest) {
         self.imageId = request.preferredImageId
+        self.scale = request.scale ?? 1
         self.thumbnail = request.thumbnail
         self.processors = request.processors
     }
 
     func hash(into hasher: inout Hasher) {
         hasher.combine(imageId)
+        hasher.combine(scale)
         hasher.combine(thumbnail)
         hasher.combine(processors.count)
     }
 
     static func == (lhs: CacheKey, rhs: CacheKey) -> Bool {
-        lhs.imageId == rhs.imageId && lhs.thumbnail == rhs.thumbnail && lhs.processors == rhs.processors
+        lhs.imageId == rhs.imageId && lhs.scale == rhs.scale && lhs.thumbnail == rhs.thumbnail && lhs.processors == rhs.processors
     }
 }
 
@@ -86,10 +89,12 @@ final class ImageLoadKey: Hashable, Sendable {
 /// Uniquely identifies a task of retrieving the decoded image.
 struct DecodedImageLoadKey: Hashable {
     let dataLoadKey: DataLoadKey
+    let scale: Float
     let thumbnail: ImageRequest.ThumbnailOptions?
 
     init(_ request: ImageRequest) {
         self.dataLoadKey = DataLoadKey(request)
+        self.scale = request.scale ?? 1
         self.thumbnail = request.thumbnail
     }
 }

Tests/NukeTests/ImagePipelineTests/ImagePipelineCoalescingTests.swift

@@ -127,6 +127,34 @@ class ImagePipelineCoalescingTests: XCTestCase {
         }
     }
 
+    // MARK: - Scale
+
+    func testOverridingImageScale() throws {
+        dataLoader.queue.isSuspended = true
+
+        // GIVEN requests with the same URLs but one accesses thumbnail
+        let request1 = ImageRequest(url: Test.url, userInfo: [.scaleKey: 2])
+        let request2 = ImageRequest(url: Test.url, userInfo: [.scaleKey: 3])
+
+        // WHEN loading images for those requests
+        expect(pipeline).toLoadImage(with: request1) { result in
+            // THEN
+            guard let image = result.value?.image else { return XCTFail() }
+            XCTAssertEqual(image.scale, 2)
+        }
+        expect(pipeline).toLoadImage(with: request2) { result in
+            // THEN
+            guard let image = result.value?.image else { return XCTFail() }
+            XCTAssertEqual(image.scale, 3)
+        }
+
+        dataLoader.queue.isSuspended = false
+
+        wait()
+
+        XCTAssertEqual(self.dataLoader.createdTaskCount, 1)
+    }
+
     // MARK: - Thumbnail
 
     func testDeduplicationGivenSameURLButDifferentThumbnailOptions() {