ci: lint with swiftformat (#316)

1. Adds a CI job that runs `swiftformat --lint` so that formatting is
enforced.
2. Updates the pre-commit hook to use
[git-format-staged](https://github.com/hallettj/git-format-staged) when
formatting.
3. Removes the SwiftPM dependency on SwiftFormat, preferring mise.
4. Formats everything.

Recommend reviewing by commit to see the changes that aren't formatting.

Fixes #33

.github/workflows/swift.yaml

@@ -82,3 +82,13 @@ jobs:
     - name: Swiftdocs
       run: |
         .buildscript/build_swift_docs.sh ${{ runner.temp }}/swiftdocs
+
+  swiftformat:
+    runs-on: macos-latest
+
+    steps:
+    - uses: actions/checkout@v4
+    - uses: jdx/mise-action@v2
+
+    - name: Run swiftformat
+      run: swiftformat --lint .

.hooks/pre-commit

@@ -1,7 +1,17 @@
 #!/bin/bash
 
-swift_files=$(git diff --diff-filter=d --staged --name-only -- '*.swift')
+# Do not run on merge
+if [[ $(git rev-parse -q --verify MERGE_HEAD) ]]; then
+    exit 0
+fi
 
-echo $swift_files | xargs swift run swiftformat --quiet
+ROOT="$(git rev-parse --show-toplevel)"
+SWIFT_FORMAT="mise x -- swiftformat"
+GIT_FORMAT_STAGED="$ROOT/Scripts/git-format-staged"
+CONFIG="${ROOT}/.swiftformat"
 
-echo $swift_files | xargs git add
+$SWIFT_FORMAT --version 1>/dev/null 2>&1
+if [ $? -eq 0 ]
+then
+    $GIT_FORMAT_STAGED --formatter "$SWIFT_FORMAT stdin --config "$CONFIG" --stdinpath '{}'" "*.swift"
+fi

Package.resolved

@@ -81,15 +81,6 @@
         "version" : "600.0.1"
       }
     },
-    {
-      "identity" : "swiftformat",
-      "kind" : "remoteSourceControl",
-      "location" : "https://github.com/nicklockwood/SwiftFormat",
-      "state" : {
-        "revision" : "dd989a46d0c6f15c016484bab8afe5e7a67a4022",
-        "version" : "0.54.0"
-      }
-    },
     {
       "identity" : "xctest-dynamic-overlay",
       "kind" : "remoteSourceControl",

Package.swift

@@ -59,8 +59,7 @@ let package = Package(
     dependencies: [
         .package(url: "https://github.com/ReactiveCocoa/ReactiveSwift.git", from: "7.1.1"),
         .package(url: "https://github.com/ReactiveX/RxSwift.git", from: "6.6.0"),
-        .package(url: "https://github.com/nicklockwood/SwiftFormat", exact: "0.54.0"),
-        .package(url: "https://github.com/swiftlang/swift-syntax", "509.0.0"..<"601.0.0-prerelease"),
+        .package(url: "https://github.com/swiftlang/swift-syntax", "509.0.0" ..< "601.0.0-prerelease"),
         .package(url: "https://github.com/pointfreeco/swift-case-paths", from: "1.1.0"),
         .package(url: "https://github.com/pointfreeco/swift-identified-collections", from: "1.0.0"),
         .package(url: "https://github.com/pointfreeco/swift-macro-testing", from: "0.4.0"),
@@ -278,7 +277,7 @@ extension PackageDescription.Product {
 }
 
 for target in package.targets {
-  var settings = target.swiftSettings ?? []
-  settings.append(.enableExperimentalFeature("StrictConcurrency=targeted"))
-  target.swiftSettings = settings
+    var settings = target.swiftSettings ?? []
+    settings.append(.enableExperimentalFeature("StrictConcurrency=targeted"))
+    target.swiftSettings = settings
 }

Samples/AlertContainer/Sources/AlertContainerScreen.swift

@@ -30,7 +30,7 @@ public struct AlertContainerScreen<BaseScreen: Screen>: Screen {
     }
 
     public func viewControllerDescription(environment: ViewEnvironment) -> ViewControllerDescription {
-        return AlertContainerViewController.description(for: self, environment: environment)
+        AlertContainerViewController.description(for: self, environment: environment)
     }
 }
 

Samples/AlertContainer/Sources/AlertContainerViewController.swift

@@ -18,13 +18,13 @@ import UIKit
 import Workflow
 import WorkflowUI
 
-private struct AlertStyleConstants {
+private enum AlertStyleConstants {
     static let viewWidth: CGFloat = 343.0
     static let buttonTitleColor = UIColor(red: 41 / 255, green: 150 / 255, blue: 204 / 255, alpha: 1.0)
     static let titleFont = UIFont.systemFont(ofSize: 18, weight: .medium)
 }
 
-internal final class AlertContainerViewController<AlertScreen: Screen>: ScreenViewController<AlertContainerScreen<AlertScreen>> {
+final class AlertContainerViewController<AlertScreen: Screen>: ScreenViewController<AlertContainerScreen<AlertScreen>> {
     private var baseScreenViewController: DescribedViewController
 
     private let dimmingView = UIView()
@@ -63,7 +63,7 @@ internal final class AlertContainerViewController<AlertScreen: Screen>: ScreenVi
         baseScreenViewController.update(screen: screen.baseScreen, environment: environment)
 
         if let alert = screen.alert {
-            if let alertView = alertView {
+            if let alertView {
                 alertView.alert = alert
             } else {
                 let inAlertView = AlertView(alert: alert)
@@ -104,7 +104,7 @@ internal final class AlertContainerViewController<AlertScreen: Screen>: ScreenVi
                 )
             }
         } else {
-            if let alertView = alertView {
+            if let alertView {
                 UIView.animate(
                     withDuration: 0.1,
                     delay: 0,
@@ -126,23 +126,23 @@ internal final class AlertContainerViewController<AlertScreen: Screen>: ScreenVi
     }
 
     override var childForStatusBarStyle: UIViewController? {
-        return baseScreenViewController
+        baseScreenViewController
     }
 
     override var childForStatusBarHidden: UIViewController? {
-        return baseScreenViewController
+        baseScreenViewController
     }
 
     override var childForHomeIndicatorAutoHidden: UIViewController? {
-        return baseScreenViewController
+        baseScreenViewController
     }
 
     override var childForScreenEdgesDeferringSystemGestures: UIViewController? {
-        return baseScreenViewController
+        baseScreenViewController
     }
 
     override public var supportedInterfaceOrientations: UIInterfaceOrientationMask {
-        return baseScreenViewController.supportedInterfaceOrientations
+        baseScreenViewController.supportedInterfaceOrientations
     }
 }
 
@@ -173,7 +173,7 @@ private final class AlertView: UIView {
     }
 
     private func commonInit() {
-        guard let alert = alert else {
+        guard let alert else {
             return
         }
         title.text = alert.title
@@ -253,6 +253,7 @@ private final class AlertButton: UIButton {
         addTarget(self, action: #selector(triggerActionHandler), for: .touchUpInside)
     }
 
+    @available(*, unavailable)
     required init?(coder aDecoder: NSCoder) {
         fatalError("init(coder:) has not been implemented")
     }

Samples/AsyncWorker/Sources/AsyncWorkerWorkflow.swift

@@ -22,7 +22,7 @@ extension AsyncWorkerWorkflow {
     }
 
     func makeInitialState() -> AsyncWorkerWorkflow.State {
-        return State(model: Model(message: "Initial State"))
+        State(model: Model(message: "Initial State"))
     }
 
     func workflowDidChange(from previousWorkflow: AsyncWorkerWorkflow, state: inout State) {}

Samples/AsyncWorker/Sources/FakeNetwork/FakeNetworkManager.swift

@@ -9,7 +9,7 @@ import Foundation
 
 class FakeNetworkManager {
     static func makeFakeNetworkRequest() -> FakeRequest {
-        return FakeRequest()
+        FakeRequest()
     }
 }
 

Samples/AsyncWorker/Sources/FakeNetwork/Model.swift

@@ -1,5 +1,5 @@
 //
-//  FakeModel.swift
+//  Model.swift
 //  AsyncWorker
 //
 //  Created by Mark Johnson on 6/16/22.

Samples/BackStackContainer/Sources/BackStackContainer.swift

@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-import WorkflowUI
 import UIKit
+import WorkflowUI
 
 public final class BackStackContainer<Content: Screen>: ScreenViewController<BackStackScreen<Content>>, UINavigationControllerDelegate {
     private let navController = UINavigationController()
@@ -69,14 +69,12 @@ public final class BackStackContainer<Content: Screen>: ScreenViewController<Bac
             return
         }
 
-        let hidden: Bool
-
-        switch topScreen.barVisibility {
+        let hidden = switch topScreen.barVisibility {
         case .hidden:
-            hidden = true
+            true
 
         case .visible:
-            hidden = false
+            false
         }
         navController.setNavigationBarHidden(hidden, animated: animated)
     }

Samples/BackStackContainer/Sources/BackStackScreen.swift

@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-import WorkflowUI
 import UIKit
+import WorkflowUI
 
 public struct BackStackScreen<ScreenType: Screen>: Screen {
     var items: [Item]
@@ -25,7 +25,7 @@ public struct BackStackScreen<ScreenType: Screen>: Screen {
     }
 
     public func viewControllerDescription(environment: ViewEnvironment) -> ViewControllerDescription {
-        return BackStackContainer.description(for: self, environment: environment)
+        BackStackContainer.description(for: self, environment: environment)
     }
 }
 
@@ -36,10 +36,10 @@ extension BackStackScreen {
         public var screen: ScreenType
         public var barVisibility: BarVisibility
 
-        public init<Key: Hashable>(key: Key?, screen: ScreenType, barVisibility: BarVisibility) {
+        public init(key: (some Hashable)?, screen: ScreenType, barVisibility: BarVisibility) {
             self.screen = screen
 
-            if let key = key {
+            if let key {
                 self.key = AnyHashable(key)
             } else {
                 self.key = AnyHashable(ObjectIdentifier(ScreenType.self))
@@ -52,7 +52,7 @@ extension BackStackScreen {
             self.init(key: key, screen: screen, barVisibility: barVisibility)
         }
 
-        public init<Key: Hashable>(key: Key?, screen: ScreenType, barContent: BackStackScreen.BarContent) {
+        public init(key: (some Hashable)?, screen: ScreenType, barContent: BackStackScreen.BarContent) {
             self.init(key: key, screen: screen, barVisibility: .visible(barContent))
         }
 
@@ -61,7 +61,7 @@ extension BackStackScreen {
             self.init(key: key, screen: screen, barContent: barContent)
         }
 
-        public init<Key: Hashable>(key: Key?, screen: ScreenType) {
+        public init(key: (some Hashable)?, screen: ScreenType) {
             let barVisibility: BarVisibility = .visible(BarContent())
             self.init(key: key, screen: screen, barVisibility: barVisibility)
         }
@@ -125,7 +125,7 @@ extension BackStackScreen.BarContent {
 
         /// Convenience factory for a default back button.
         public static func back(handler: @escaping () -> Void) -> Button {
-            return Button(content: .text("Back"), handler: handler)
+            Button(content: .text("Back"), handler: handler)
         }
     }
 }

Samples/BackStackContainer/Sources/ScreenWrapperViewController.swift

@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-import WorkflowUI
 import UIKit
+import WorkflowUI
 
 /**
  Wrapper view controller for being hosted in a backstack. Handles updating the bar button items.
@@ -58,7 +58,7 @@ final class ScreenWrapperViewController<ScreenType: Screen>: UIViewController {
     }
 
     func matches(item: BackStackScreen<ScreenType>.Item) -> Bool {
-        return item.key == key
+        item.key == key
             && type(of: item.screen) == ScreenType.self
     }
 
@@ -97,16 +97,16 @@ final class ScreenWrapperViewController<ScreenType: Screen>: UIViewController {
             }
         }
 
-        let title: String
-        switch barContent.title {
+        let title: String = switch barContent.title {
         case .none:
-            title = ""
+            ""
         case .text(let text):
-            title = text
+            text
         }
         navigationItem.title = title
     }
 
+    @available(*, unavailable)
     required init?(coder aDecoder: NSCoder) {
         fatalError("init(coder:) has not been implemented")
     }
@@ -127,6 +127,7 @@ extension ScreenWrapperViewController {
             update(with: button)
         }
 
+        @available(*, unavailable)
         required init?(coder aDecoder: NSCoder) {
             fatalError("init(coder:) has not been implemented")
         }

Samples/ModalContainer/Sources/ModalContainerScreen.swift

@@ -30,7 +30,7 @@ public struct ModalContainerScreen<BaseScreen: Screen>: Screen {
     }
 
     public func viewControllerDescription(environment: ViewEnvironment) -> ViewControllerDescription {
-        return ModalContainerViewController.description(for: self, environment: environment)
+        ModalContainerViewController.description(for: self, environment: environment)
     }
 }
 
@@ -55,7 +55,7 @@ public struct ModalContainerScreenModal {
     /// A key used to differentiate modal screens during updates
     public var key: AnyHashable
 
-    public init<Key: Hashable>(screen: AnyScreen, style: Style = .fullScreen, key: Key, animated: Bool = true) {
+    public init(screen: AnyScreen, style: Style = .fullScreen, key: some Hashable, animated: Bool = true) {
         self.screen = screen
         self.style = style
         self.key = AnyHashable(key)