Provide a Snapshotting strategy using UIView.systemLayoutSizeFitting

Sources/SnapshotTesting/Snapshotting/UIView.swift

@@ -34,6 +34,43 @@ extension Snapshotting where Value == UIView, Format == UIImage {
         )
       }
   }
+
+  /// A snapshot strategy for comparing views based on pixel equality.
+  ///
+  /// - Parameters:
+  ///   - config: A set of device configuration settings.
+  ///   - precision: The percentage of pixels that must match.
+  ///   - perceptualPrecision: The percentage a pixel must match the source pixel to be considered a match. [98-99% mimics the precision of the human eye.](http://zschuessler.github.io/DeltaE/learn/#toc-defining-delta-e)
+  ///   - targetSize: The size that you prefer for the view. To obtain a view that is as small as possible, specify the constant [layoutFittingCompressedSize](https://developer.apple.com/documentation/uikit/uiview/1622568-layoutfittingcompressedsize). To obtain a view that is as large as possible, specify the constant [layoutFittingExpandedSize](https://developer.apple.com/documentation/uikit/uiview/1622532-layoutfittingexpandedsize).
+  ///   - horizontalFittingPriority: The priority for horizontal constraints. Specify [fittingSizeLevel](https://developer.apple.com/documentation/uikit/uilayoutpriority/1622248-fittingsizelevel) to get a width that is as close as possible to the width value of `targetSize`.
+  ///   - verticalFittingPriority: The priority for vertical constraints. Specify [fittingSizeLevel](https://developer.apple.com/documentation/uikit/uilayoutpriority/1622248-fittingsizelevel) to get a height that is as close as possible to the height value of `targetSize`.
+  ///   - traits: A trait collection override.
+  public static func image(
+    drawHierarchyInKeyWindow: Bool = false,
+    precision: Float = 1,
+    perceptualPrecision: Float = 1,
+    targetSize: CGSize,
+    horizontalFittingPriority: UILayoutPriority,
+    verticalFittingPriority: UILayoutPriority,
+    traits: UITraitCollection = .init()
+    )
+    -> Snapshotting {
+
+      return SimplySnapshotting.image(precision: precision, perceptualPrecision: perceptualPrecision, scale: traits.displayScale).asyncPullback { view in
+        let size = view.systemLayoutSizeFitting(
+          targetSize,
+          withHorizontalFittingPriority: horizontalFittingPriority,
+          verticalFittingPriority: verticalFittingPriority
+        )
+        return snapshotView(
+          config: .init(safeArea: .zero, size: size, traits: .init()),
+          drawHierarchyInKeyWindow: drawHierarchyInKeyWindow,
+          traits: traits,
+          view: view,
+          viewController: .init()
+        )
+      }
+  }
 }
 
 extension Snapshotting where Value == UIView, Format == String {

Tests/SnapshotTestingTests/SnapshotTestingTests.swift

@@ -853,6 +853,23 @@ final class SnapshotTestingTests: XCTestCase {
     assertSnapshot(matching: view, as: .recursiveDescription)
     #endif
   }
+
+  func testSystemLayoutFittingWithView() {
+    #if os(iOS)
+    let label = UILabel()
+    label.text = "What's the point?"
+    label.numberOfLines = .zero
+
+    assertSnapshot(
+      matching: label,
+      as: .image(
+        targetSize: CGSize(width: 50, height: UIView.layoutFittingExpandedSize.height),
+        horizontalFittingPriority: .required,
+        verticalFittingPriority: .fittingSizeLevel
+      )
+    )
+    #endif
+  }
 
   func testUIViewControllerLifeCycle() {
     #if os(iOS)