Add CI, SwiftLint and SwiftFormat

.github/workflows/ci.yml

@@ -0,0 +1,56 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  lint:
+    name: Lint
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v7
+      - name: Install SwiftLint
+        run: brew install swiftlint
+      - name: Run SwiftLint
+        run: swiftlint --strict
+
+  format:
+    name: Format
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v7
+      - name: Install SwiftFormat
+        run: brew install swiftformat
+      # Paths come first: --lint would otherwise swallow the one after it.
+      - name: Check formatting
+        run: swiftformat Sources Preview --lint
+
+  build:
+    name: Build and Analyse
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v7
+      - name: Install SwiftLint
+        run: brew install swiftlint
+      - name: Build and Analyse
+        run: |
+          set -o pipefail
+          for scheme in Macstify MacstifyPreview; do
+            xcodebuild build analyze \
+              -project Macstify.xcodeproj \
+              -scheme "$scheme" \
+              -destination 'generic/platform=macOS' \
+              CODE_SIGN_IDENTITY="" \
+              CODE_SIGNING_REQUIRED=NO \
+              CODE_SIGNING_ALLOWED=NO \
+              | tee -a build.log
+          done
+      - name: SwiftLint Analyse
+        run: swiftlint analyze --strict --compiler-log-path build.log

.swift-version

@@ -0,0 +1 @@
+6.0

.swiftformat

@@ -0,0 +1 @@
+--swiftversion 6.0

.swiftlint.yml

@@ -0,0 +1,16 @@
+excluded:
+  - build # xcodebuild output
+
+# Require trailing commas to match SwiftFormat's trailingCommas rule.
+trailing_comma:
+  mandatory_comma: true
+
+# Geometry code uses short names like x, y, dx, dy.
+identifier_name:
+  min_length:
+    warning: 1
+    error: 1
+
+analyzer_rules:
+  - unused_declaration
+  - unused_import

Preview/PreviewApp.swift

@@ -22,6 +22,8 @@ import AppKit
 enum PreviewApp {
     private static var delegate: PreviewDelegate?
 
+    // Called by the Swift runtime through @main, never from code.
+    // swiftlint:disable:next unused_declaration
     static func main() {
         let options: Options
         do {
@@ -112,13 +114,17 @@ enum PreviewApp {
         _ = NSApplication.shared
 
         var settings = MacstifySettings.load()
-        if isPreview { settings = settings.previewAdjusted }
-        if let speed { settings.speed = speed }
+        if isPreview {
+            settings = settings.previewAdjusted
+        }
+        if let speed {
+            settings.speed = speed
+        }
 
         let rect = NSRect(origin: .zero, size: size)
         let engine = MacstifyEngine(settings: settings)
         engine.reset(bounds: rect)
-        for _ in 0..<frames {
+        for _ in 0 ..< frames {
             engine.step(dt: 1.0 / 60.0)
         }
 
@@ -187,7 +193,9 @@ enum PreviewApp {
 }
 
 private final class PreviewDelegate: NSObject, NSApplicationDelegate {
-    func applicationShouldTerminateAfterLastWindowClosed(_ sender: NSApplication) -> Bool { true }
+    func applicationShouldTerminateAfterLastWindowClosed(_: NSApplication) -> Bool {
+        true
+    }
 }
 
 private struct Options {
@@ -203,34 +211,13 @@ private struct Options {
         var iterator = arguments.makeIterator()
         while let argument = iterator.next() {
             switch argument {
-            case "--snapshot":
-                snapshotPath = try Self.value(after: argument, from: &iterator)
-            case "--frames":
-                let raw = try Self.value(after: argument, from: &iterator)
-                guard let value = Int(raw), value > 0 else {
-                    throw OptionError("--frames expects a positive integer, got \(raw)")
-                }
-                frames = value
-            case "--size":
-                let raw = try Self.value(after: argument, from: &iterator)
-                let parts = raw.lowercased().split(separator: "x")
-                guard parts.count == 2,
-                      let width = Double(parts[0]), let height = Double(parts[1]),
-                      width > 0, height > 0 else {
-                    throw OptionError("--size expects WIDTHxHEIGHT, got \(raw)")
-                }
-                size = NSSize(width: width, height: height)
-                explicitSize = true
-            case "--speed":
-                let raw = try Self.value(after: argument, from: &iterator)
-                guard let value = Double(raw), value > 0 else {
-                    throw OptionError("--speed expects a positive number, got \(raw)")
-                }
-                speed = value
             case "--options":
                 showOptions = true
             case "--preview":
                 isPreview = true
+            case "--snapshot", "--frames", "--size", "--speed":
+                let raw = try Self.value(after: argument, from: &iterator)
+                try set(argument, to: raw, explicitSize: &explicitSize)
             default:
                 throw OptionError("unknown argument: \(argument)")
             }
@@ -242,6 +229,37 @@ private struct Options {
         }
     }
 
+    private mutating func set(_ flag: String, to raw: String, explicitSize: inout Bool) throws {
+        switch flag {
+        case "--snapshot":
+            snapshotPath = raw
+        case "--frames":
+            guard let value = Int(raw), value > 0 else {
+                throw OptionError("\(flag) expects a positive integer, got \(raw)")
+            }
+            frames = value
+        case "--size":
+            size = try Self.parseSize(raw)
+            explicitSize = true
+        default:
+            guard let value = Double(raw), value > 0 else {
+                throw OptionError("\(flag) expects a positive number, got \(raw)")
+            }
+            speed = value
+        }
+    }
+
+    private static func parseSize(_ raw: String) throws -> NSSize {
+        let parts = raw.lowercased().split(separator: "x")
+        guard parts.count == 2,
+              let width = Double(parts[0]), let height = Double(parts[1]),
+              width > 0, height > 0
+        else {
+            throw OptionError("--size expects WIDTHxHEIGHT, got \(raw)")
+        }
+        return NSSize(width: width, height: height)
+    }
+
     private static func value(
         after flag: String,
         from iterator: inout some IteratorProtocol<String>
@@ -255,5 +273,7 @@ private struct Options {
 
 private struct OptionError: LocalizedError {
     let errorDescription: String?
-    init(_ message: String) { errorDescription = message }
+    init(_ message: String) {
+        errorDescription = message
+    }
 }

README.md

@@ -69,6 +69,13 @@ snapshots are written at 2x, as on a Retina display.
 
 The screenshots above were produced with `--snapshot`.
 
+CI builds and analyses both schemes and runs the same lint and format checks you can run locally:
+
+```sh
+swiftlint --strict
+swiftformat Sources Preview --lint
+```
+
 ### Thumbnail
 
 The picker in System Settings shows `Contents/Resources/thumbnail.png` and `thumbnail@2x.png`

Sources/ConfigureSheetController.swift

@@ -39,60 +39,65 @@ final class ConfigureSheetController: NSObject {
     // MARK: - Interface
 
     private func buildInterface() {
-        let integer: (Double) -> String = { String(Int($0.rounded())) }
-        let multiplier: (Double) -> String = { String(format: "%.2f×", $0) }
+        let root = NSStackView(views: [makeGrid(), makeButtons()])
+        root.orientation = .vertical
+        root.alignment = .width
+        root.spacing = 20
+        root.edgeInsets = NSEdgeInsets(top: 20, left: 20, bottom: 20, right: 20)
+        root.translatesAutoresizingMaskIntoConstraints = false
 
-        let gridRows: [[NSView]] = [
-            makeRow(
-                title: "Shapes:",
-                control: makeStepper(range: MacstifySettings.polygonCountRange),
-                describe: integer,
-                read: { Double($0.polygonCount) },
-                write: { $0.polygonCount = Int($1.rounded()) }
-            ),
-            makeRow(
-                title: "Vertices:",
-                control: makeStepper(range: MacstifySettings.vertexCountRange),
-                describe: integer,
-                read: { Double($0.vertexCount) },
-                write: { $0.vertexCount = Int($1.rounded()) }
-            ),
-            makeRow(
-                title: "Trail length:",
-                control: makeSlider(range: MacstifySettings.trailLengthRange),
-                describe: integer,
-                read: { Double($0.trailLength) },
-                write: { $0.trailLength = Int($1.rounded()) }
-            ),
-            makeRow(
-                title: "Speed:",
-                control: makeSlider(range: MacstifySettings.speedRange),
-                describe: multiplier,
-                read: { $0.speed },
-                write: { $0.speed = $1 }
-            ),
-            makeRow(
-                title: "Line width:",
-                control: makeSlider(range: MacstifySettings.lineWidthRange),
-                describe: { String(format: "%.1f pt", $0) },
-                read: { $0.lineWidth },
-                write: { $0.lineWidth = $1 }
-            ),
-            makeRow(
-                title: "Color speed:",
-                control: makeSlider(range: MacstifySettings.colorSpeedRange),
-                describe: multiplier,
-                read: { $0.colorSpeed },
-                write: { $0.colorSpeed = $1 }
-            ),
-        ]
+        let content = NSView()
+        content.addSubview(root)
+        NSLayoutConstraint.activate([
+            root.leadingAnchor.constraint(equalTo: content.leadingAnchor),
+            root.trailingAnchor.constraint(equalTo: content.trailingAnchor),
+            root.topAnchor.constraint(equalTo: content.topAnchor),
+            root.bottomAnchor.constraint(equalTo: content.bottomAnchor),
+        ])
 
-        let grid = NSGridView(views: gridRows)
+        window.contentView = content
+        content.layoutSubtreeIfNeeded()
+        window.setContentSize(content.fittingSize)
+    }
+
+    private func makeGrid() -> NSGridView {
+        let grid = NSGridView(views: makeRows())
         grid.translatesAutoresizingMaskIntoConstraints = false
         grid.column(at: 0).xPlacement = .trailing
         grid.rowSpacing = 10
         grid.columnSpacing = 10
+        return grid
+    }
+
+    private func makeRows() -> [[NSView]] {
+        let integer: (Double) -> String = { String(Int($0.rounded())) }
+        let multiplier: (Double) -> String = { String(format: "%.2f×", $0) }
+        let points: (Double) -> String = { String(format: "%.1f pt", $0) }
+        let settings = MacstifySettings.self
+
+        return [
+            makeRow(title: "Shapes:", control: makeStepper(range: settings.polygonCountRange),
+                    describe: integer, read: { Double($0.polygonCount) },
+                    write: { $0.polygonCount = Int($1.rounded()) }),
+            makeRow(title: "Vertices:", control: makeStepper(range: settings.vertexCountRange),
+                    describe: integer, read: { Double($0.vertexCount) },
+                    write: { $0.vertexCount = Int($1.rounded()) }),
+            makeRow(title: "Trail length:", control: makeSlider(range: settings.trailLengthRange),
+                    describe: integer, read: { Double($0.trailLength) },
+                    write: { $0.trailLength = Int($1.rounded()) }),
+            makeRow(title: "Speed:", control: makeSlider(range: settings.speedRange),
+                    describe: multiplier, read: { $0.speed },
+                    write: { $0.speed = $1 }),
+            makeRow(title: "Line width:", control: makeSlider(range: settings.lineWidthRange),
+                    describe: points, read: { $0.lineWidth },
+                    write: { $0.lineWidth = $1 }),
+            makeRow(title: "Color speed:", control: makeSlider(range: settings.colorSpeedRange),
+                    describe: multiplier, read: { $0.colorSpeed },
+                    write: { $0.colorSpeed = $1 }),
+        ]
+    }
 
+    private func makeButtons() -> NSStackView {
         let restore = NSButton(title: "Restore Defaults", target: self,
                                action: #selector(restoreDefaults))
         let cancel = NSButton(title: "Cancel", target: self, action: #selector(cancel))
@@ -105,26 +110,7 @@ final class ConfigureSheetController: NSObject {
         buttons.spacing = 12
         buttons.setViews([restore], in: .leading)
         buttons.setViews([cancel, ok], in: .trailing)
-
-        let root = NSStackView(views: [grid, buttons])
-        root.orientation = .vertical
-        root.alignment = .width
-        root.spacing = 20
-        root.edgeInsets = NSEdgeInsets(top: 20, left: 20, bottom: 20, right: 20)
-        root.translatesAutoresizingMaskIntoConstraints = false
-
-        let content = NSView()
-        content.addSubview(root)
-        NSLayoutConstraint.activate([
-            root.leadingAnchor.constraint(equalTo: content.leadingAnchor),
-            root.trailingAnchor.constraint(equalTo: content.trailingAnchor),
-            root.topAnchor.constraint(equalTo: content.topAnchor),
-            root.bottomAnchor.constraint(equalTo: content.bottomAnchor),
-        ])
-
-        window.contentView = content
-        content.layoutSubtreeIfNeeded()
-        window.setContentSize(content.fittingSize)
+        return buttons
     }
 
     private func makeRow(
@@ -172,7 +158,7 @@ final class ConfigureSheetController: NSObject {
     }
 
     private func makeSlider(range: ClosedRange<Int>) -> NSSlider {
-        makeSlider(range: Double(range.lowerBound)...Double(range.upperBound))
+        makeSlider(range: Double(range.lowerBound) ... Double(range.upperBound))
     }
 
     /// Pushes `settings` back out to every control, so one refresh path serves
@@ -212,7 +198,9 @@ final class ConfigureSheetController: NSObject {
             parent.endSheet(window, returnCode: saved ? .OK : .cancel)
         } else {
             // Reachable from the preview app, which shows the sheet standalone.
-            if NSApp.modalWindow === window { NSApp.stopModal() }
+            if NSApp.modalWindow === window {
+                NSApp.stopModal()
+            }
             window.orderOut(nil)
         }
         onDismiss(saved)