Adopt "complete" Swift concurrency

.github/workflows/ci.yml

@@ -63,9 +63,11 @@ jobs:
         run: Scripts/build.swift spm ${{ matrix.platform }} `which xcpretty`
   bazel:
     name: Bazel
-    runs-on: macOS-12
+    runs-on: macOS-latest
     steps:
       - name: Checkout Repo
         uses: actions/checkout@v4
+      - name: Select Xcode Version
+        run: sudo xcode-select --switch /Applications/Xcode_15.4.app/Contents/Developer
       - name: Build and Test
-        run: bazel test //...
+        run: bazel test //... --xcode_version=15.4.0

BUILD.bazel

@@ -12,6 +12,7 @@ swift_library(
     name = "Paralayout.lib",
     srcs = glob(["Paralayout/**/*.swift"]),
     module_name = "Paralayout",
+    copts = ["-strict-concurrency=complete"],
     tags = ["manual"],
     visibility = ["//visibility:public"],
     deps = [],
@@ -22,6 +23,7 @@ swift_library(
     testonly = True,
     srcs = glob(["ParalayoutTests/**/*.swift"]),
     module_name = "ParalayoutTests",
+    copts = ["-strict-concurrency=complete"],
     tags = ["manual"],
     deps = [":Paralayout.lib"],
 )

Example/ParalayoutSnapshotTests/ViewAlignmentSnapshotTests.swift

@@ -19,6 +19,7 @@ import SnapshotTesting
 
 final class ViewAlignmentSnapshotTests: SnapshotTestCase {
 
+    @MainActor
     func testSiblingAlignment() {
         let containerView = UIView(frame: .init(x: 0, y: 0, width: 200, height: 200))
         containerView.backgroundColor = .white
@@ -31,6 +32,7 @@ final class ViewAlignmentSnapshotTests: SnapshotTestCase {
         secondSubview.backgroundColor = .red
         containerView.addSubview(secondSubview)
 
+        @MainActor
         func verifySnapshot(
             receiverPosition: Position,
             targetPosition: Position,
@@ -80,6 +82,7 @@ final class ViewAlignmentSnapshotTests: SnapshotTestCase {
         verifySnapshot(receiverPosition: .center, targetPosition: .topRight, verticalOffset: -15)
     }
 
+    @MainActor
     func testLayoutDirection() {
         let containerView = UIView(frame: .init(x: 0, y: 0, width: 100, height: 100))
         containerView.backgroundColor = .white
@@ -88,6 +91,7 @@ final class ViewAlignmentSnapshotTests: SnapshotTestCase {
         targetView.backgroundColor = .lightGray
         containerView.addSubview(targetView)
 
+        @MainActor
         func addAlignedSubview(
             receiverPosition: Position,
             receiverLayoutDirection: UIUserInterfaceLayoutDirection,
@@ -140,6 +144,7 @@ final class ViewAlignmentSnapshotTests: SnapshotTestCase {
         assertSnapshot(matching: containerView, as: .image, named: nameForSnapshot(with: []))
     }
 
+    @MainActor
     func testTransformHasNoEffect() {
         let containerView = UIView(frame: .init(x: 0, y: 0, width: 100, height: 100))
         containerView.backgroundColor = .white
@@ -152,6 +157,7 @@ final class ViewAlignmentSnapshotTests: SnapshotTestCase {
         secondSubview.backgroundColor = .red
         containerView.addSubview(secondSubview)
 
+        @MainActor
         func verifySnapshot(
             receiverTransform: CGAffineTransform,
             targetTransform: CGAffineTransform,
@@ -185,6 +191,7 @@ final class ViewAlignmentSnapshotTests: SnapshotTestCase {
         verifySnapshot(receiverTransform: .identity, targetTransform: .init(scaleX: 2, y: 3))
     }
 
+    @MainActor
     func testNonZeroBoundsOrigin() {
         let containerView = UIView(frame: CGRect(x: 0, y: 0, width: 200, height: 200))
         containerView.backgroundColor = .white
@@ -213,6 +220,7 @@ final class ViewAlignmentSnapshotTests: SnapshotTestCase {
         assertSnapshot(matching: containerView, as: .image, named: nameForSnapshot(with: []))
     }
 
+    @MainActor
     func testAlignmentWithLayoutMargins() {
         let containerView = UIView(frame: CGRect(x: 0, y: 0, width: 200, height: 200))
         containerView.backgroundColor = .white
@@ -246,6 +254,7 @@ final class ViewAlignmentSnapshotTests: SnapshotTestCase {
         assertSnapshot(matching: containerView, as: .image, named: nameForSnapshot(with: ["bothLayoutMargins"]))
     }
 
+    @MainActor
     func testAlignmentUsingCapInsets() {
         let containerView = UIView(frame: CGRect(x: 0, y: 0, width: 250, height: 100))
         containerView.backgroundColor = .white
@@ -269,6 +278,7 @@ final class ViewAlignmentSnapshotTests: SnapshotTestCase {
         assertSnapshot(matching: containerView, as: .image, named: nameForSnapshot(with: []))
     }
 
+    @MainActor
     func testAlignmentUsingFirstLine() {
         let containerView = UIView(frame: CGRect(x: 0, y: 0, width: 250, height: 100))
         containerView.backgroundColor = .white
@@ -299,6 +309,7 @@ final class ViewAlignmentSnapshotTests: SnapshotTestCase {
         assertSnapshot(matching: containerView, as: .image, named: nameForSnapshot(with: []))
     }
 
+    @MainActor
     func testAlignmentUsingFirstLineCapInsets() {
         let containerView = UIView(frame: CGRect(x: 0, y: 0, width: 250, height: 100))
         containerView.backgroundColor = .white
@@ -329,6 +340,7 @@ final class ViewAlignmentSnapshotTests: SnapshotTestCase {
         assertSnapshot(matching: containerView, as: .image, named: nameForSnapshot(with: []))
     }
 
+    @MainActor
     func testAlignmentWithRect() {
         let containerView = UIView(frame: CGRect(x: 0, y: 0, width: 200, height: 200))
         containerView.backgroundColor = .white
@@ -365,6 +377,7 @@ final class ViewAlignmentSnapshotTests: SnapshotTestCase {
         assertSnapshot(matching: containerView, as: .image, named: nameForSnapshot(with: []))
     }
 
+    @MainActor
     func testAlignmentWithFrame() {
         let targetTransform = CGAffineTransform(translationX: -20, y: 10)
         let receiverTransform = CGAffineTransform(scaleX: 0.8, y: 0.8)
@@ -390,6 +403,7 @@ final class ViewAlignmentSnapshotTests: SnapshotTestCase {
         receiverView.transform = receiverTransform
         containerView.addSubview(receiverView)
 
+        @MainActor
         func updateMirrorViews() {
             targetView.transform = .identity
             targetFrameView.frame = targetView.frame.applying(targetView.transform.inverted())

Example/ParalayoutSnapshotTests/ViewDistributionSnapshotTests.swift

@@ -19,6 +19,7 @@ import SnapshotTesting
 
 final class ViewDistributionSnapshotTests: SnapshotTestCase {
 
+    @MainActor
     func testDistribution() {
         let containerView = UIView(frame: CGRect(x: 0, y: 0, width: 100, height: 200))
         containerView.backgroundColor = .white
@@ -45,6 +46,7 @@ final class ViewDistributionSnapshotTests: SnapshotTestCase {
         assertSnapshot(matching: containerView, as: .image, named: nameForSnapshot(with: ["vertical"]))
     }
 
+    @MainActor
     func testDistributionIgnoresTransform() {
         let containerView = UIView(frame: CGRect(x: 0, y: 0, width: 100, height: 200))
         containerView.backgroundColor = .white
@@ -72,6 +74,7 @@ final class ViewDistributionSnapshotTests: SnapshotTestCase {
         assertSnapshot(matching: containerView, as: .image, named: nameForSnapshot(with: []))
     }
 
+    @MainActor
     func testDistributionUsingCapInsets() {
         let containerView = UIView(frame: CGRect(x: 0, y: 0, width: 100, height: 80))
         containerView.backgroundColor = .white
@@ -104,6 +107,7 @@ final class ViewDistributionSnapshotTests: SnapshotTestCase {
         assertSnapshot(matching: containerView, as: .image, named: nameForSnapshot(with: []))
     }
 
+    @MainActor
     func testHorizontalDistributionFollowsLayoutDirection() {
         let view = HorizontalDistributionView(frame: CGRect(x: 0, y: 0, width: 160, height: 60))
 

Example/ParalayoutSnapshotTests/ViewSpreadingSnapshotTests.swift

@@ -19,6 +19,7 @@ import SnapshotTesting
 
 final class ViewSpeadingSnapshotTests: SnapshotTestCase {
 
+    @MainActor
     func testHorizontallySpreadSubviews() {
         let container = UIView(frame: CGRect(x: 0, y: 0, width: 400, height: 100))
         container.backgroundColor = .white
@@ -35,6 +36,7 @@ final class ViewSpeadingSnapshotTests: SnapshotTestCase {
         greenView.backgroundColor = .green
         container.addSubview(greenView)
 
+        @MainActor
         func verifySnapshot(
             margin: CGFloat = 0,
             inRect rect: CGRect? = nil,
@@ -92,6 +94,7 @@ final class ViewSpeadingSnapshotTests: SnapshotTestCase {
         verifySnapshot(margin: 40, inRect: CGRect(x: 20, y: 10, width: 300, height: 50))
     }
 
+    @MainActor
     func testVerticallySpreadSubviews() {
         let container = UIView(frame: CGRect(x: 0, y: 0, width: 400, height: 100))
         container.backgroundColor = .white
@@ -108,6 +111,7 @@ final class ViewSpeadingSnapshotTests: SnapshotTestCase {
         greenView.backgroundColor = .green
         container.addSubview(greenView)
 
+        @MainActor
         func verifySnapshot(
             margin: CGFloat = 0,
             inRect rect: CGRect? = nil,

Paralayout/Alignable.swift

@@ -19,10 +19,12 @@ import UIKit
 /// Describes an object that can participate in alignment. In practice, this represents a view.
 public protocol Alignable {
 
+    @MainActor
     var alignmentContext: AlignmentContext { get }
 
 }
 
+@MainActor
 public struct AlignmentContext {
 
     // MARK: - Life Cycle
@@ -47,6 +49,7 @@ public struct AlignmentContext {
 
 extension UIView: Alignable {
 
+    @MainActor
     public var alignmentContext: AlignmentContext {
         return AlignmentContext(view: self, alignmentBounds: bounds)
     }
@@ -168,6 +171,7 @@ public struct FrameAlignmentProxy: Alignable {
 
     // MARK: - Private Methods
 
+    @MainActor
     private func withViewInSuperview<T>(view: UIView, perform: (_ superview: UIView) -> T) -> T {
         if let superview = view.superview {
             return perform(superview)

Paralayout/Angle.swift

@@ -16,7 +16,7 @@
 
 import CoreGraphics
 
-public struct Angle: Comparable {
+public struct Angle: Comparable, Sendable {
 
     // MARK: - Public Static Properties
 

Paralayout/AspectRatio.swift

@@ -17,7 +17,7 @@
 import UIKit
 
 /// A value type representing the ratio between a width and a height.
-public struct AspectRatio: Comparable, CustomDebugStringConvertible {
+public struct AspectRatio: Comparable, CustomDebugStringConvertible, Sendable {
 
     // MARK: - Public Static Properties
 
@@ -105,15 +105,15 @@ public struct AspectRatio: Comparable, CustomDebugStringConvertible {
     ///
     /// - parameter width: The desired width.
     /// - parameter scaleFactor: The view/window/screen to use for pixel rounding.
-    public func height(forWidth width: CGFloat, in scaleFactor: ScaleFactorProviding) -> CGFloat {
+    @MainActor public func height(forWidth width: CGFloat, in scaleFactor: ScaleFactorProviding) -> CGFloat {
         return (ratioHeight * width / ratioWidth).roundedToPixel(in: scaleFactor)
     }
 
     /// Returns the width of the aspect ratio for a given `height` rounded to the nearest pixel.
     ///
     /// - parameter height: The desired height.
     /// - parameter scaleFactor: The view/window/screen to use for pixel rounding.
-    public func width(forHeight height: CGFloat, in scaleFactor: ScaleFactorProviding) -> CGFloat {
+    @MainActor public func width(forHeight height: CGFloat, in scaleFactor: ScaleFactorProviding) -> CGFloat {
         return (ratioWidth * height / ratioHeight).roundedToPixel(in: scaleFactor)
     }
 
@@ -122,7 +122,7 @@ public struct AspectRatio: Comparable, CustomDebugStringConvertible {
     ///
     /// - parameter width: The desired width.
     /// - parameter scaleFactor: The view/window/screen to use for pixel rounding.
-    public func size(forWidth width: CGFloat, in scaleFactor: ScaleFactorProviding) -> CGSize {
+    @MainActor public func size(forWidth width: CGFloat, in scaleFactor: ScaleFactorProviding) -> CGSize {
         return CGSize(
             width: width,
             height: height(forWidth: width, in: scaleFactor)
@@ -134,7 +134,7 @@ public struct AspectRatio: Comparable, CustomDebugStringConvertible {
     ///
     /// - parameter height: The desired height.
     /// - parameter scaleFactor: The view/window/screen to use for pixel rounding.
-    public func size(forHeight height: CGFloat, in scaleFactor: ScaleFactorProviding) -> CGSize {
+    @MainActor public func size(forHeight height: CGFloat, in scaleFactor: ScaleFactorProviding) -> CGSize {
         return CGSize(
             width: width(forHeight: height, in: scaleFactor),
             height: height
@@ -147,7 +147,7 @@ public struct AspectRatio: Comparable, CustomDebugStringConvertible {
     /// - parameter size: The bounding size.
     /// - parameter scaleFactor: The view/window/screen to use for pixel alignment.
     /// - returns: A size with the receiver's aspect ratio, no larger than the bounding size.
-    public func size(toFit size: CGSize, in scaleFactor: ScaleFactorProviding) -> CGSize {
+    @MainActor public func size(toFit size: CGSize, in scaleFactor: ScaleFactorProviding) -> CGSize {
         if size.aspectRatio <= self {
             // Match width, narrow the height.
             let fitHeight = min(size.height, height(forWidth: size.width, in: scaleFactor))
@@ -169,7 +169,7 @@ public struct AspectRatio: Comparable, CustomDebugStringConvertible {
     /// - parameter scaleFactor: The view/window/screen to use for pixel alignment.
     /// - parameter layoutDirection: The effective layout direction of the view in which the `rect` is defined.
     /// - returns: A rect with the receiver's aspect ratio, strictly within the bounding rect.
-    public func rect(
+    @MainActor public func rect(
         toFit rect: CGRect,
         at position: Position,
         in scaleFactor: ScaleFactorProviding,
@@ -193,7 +193,7 @@ public struct AspectRatio: Comparable, CustomDebugStringConvertible {
     /// - parameter context: The view/window/screen that provides the scale factor and effective layout direction in
     /// which the rect should be positioned.
     /// - returns: A rect with the receiver's aspect ratio, strictly within the bounding rect.
-    public func rect(
+    @MainActor public func rect(
         toFit rect: CGRect,
         at position: Position,
         in context: (ScaleFactorProviding & LayoutDirectionProviding)
@@ -212,7 +212,7 @@ public struct AspectRatio: Comparable, CustomDebugStringConvertible {
     /// - parameter size: The bounding size.
     /// - parameter scaleFactor: The view/window/screen to use for pixel alignment.
     /// - returns: A size with the receiver's aspect ratio, at least as large as the bounding size.
-    public func size(toFill size: CGSize, in scaleFactor: ScaleFactorProviding) -> CGSize {
+    @MainActor public func size(toFill size: CGSize, in scaleFactor: ScaleFactorProviding) -> CGSize {
         if size.aspectRatio <= self {
             // Match height, expand the width.
             let fillWidth = width(forHeight: size.height, in: scaleFactor)
@@ -234,7 +234,7 @@ public struct AspectRatio: Comparable, CustomDebugStringConvertible {
     /// - parameter scaleFactor: The view/window/screen to use for pixel alignment.
     /// - parameter layoutDirection: The effective layout direction of the view in which the `rect` is defined.
     /// - returns: A rect with the receiver's aspect ratio, strictly containing the bounding rect.
-    public func rect(
+    @MainActor public func rect(
         toFill rect: CGRect,
         at position: Position,
         in scaleFactor: ScaleFactorProviding,
@@ -257,7 +257,7 @@ public struct AspectRatio: Comparable, CustomDebugStringConvertible {
     /// - parameter context: The view/window/screen that provides the scale factor and effective layout direction in
     /// which the rect should be positioned.
     /// - returns: A rect with the receiver's aspect ratio, strictly containing the bounding rect.
-    public func rect(
+    @MainActor public func rect(
         toFill rect: CGRect,
         at position: Position,
         in context: (ScaleFactorProviding & LayoutDirectionProviding)
@@ -294,6 +294,7 @@ extension CGRect {
 
     // MARK: - Life Cycle
 
+    @MainActor
     fileprivate init(
         size newSize: CGSize,
         at position: Position,

Paralayout/Interpolation.swift

@@ -102,7 +102,7 @@ public enum Clamp {
 
 // MARK: -
 
-public struct Interpolation: Comparable {
+public struct Interpolation: Comparable, Sendable {
 
     // MARK: - Public Types
 

Paralayout/LayoutDirection.swift

@@ -19,6 +19,7 @@ import UIKit
 /// Defines an object that vends its current user interface layout direction.
 public protocol LayoutDirectionProviding {
 
+    @MainActor
     var effectiveUserInterfaceLayoutDirection: UIUserInterfaceLayoutDirection { get }
 
 }