Refactor: move hotkey display-string formatting onto HotKeyCombination

Sources/Stag/Models/HotKeyCombination+Display.swift

@@ -0,0 +1,39 @@
+import Cocoa
+
+extension HotKeyCombination {
+    /// Human-readable shortcut string, e.g. "⇧⌘1". Modifiers are emitted in the
+    /// macOS-standard order (⌃⌥⇧⌘) followed by the key label. Returns "" when no
+    /// key is set (keyCode 0); callers present their own placeholder there.
+    var displayString: String {
+        guard keyCode != 0 else { return "" }
+        var parts: [String] = []
+        let flags = modifierFlags
+        if flags.contains(.control) { parts.append("\u{2303}") }   // ⌃
+        if flags.contains(.option)  { parts.append("\u{2325}") }   // ⌥
+        if flags.contains(.shift)   { parts.append("\u{21E7}") }   // ⇧
+        if flags.contains(.command) { parts.append("\u{2318}") }   // ⌘
+        parts.append(Self.keyName(keyCode))
+        return parts.joined()
+    }
+
+    /// Maps a macOS ANSI virtual keycode to its display label. Unknown codes fall
+    /// back to "Key<code>".
+    static func keyName(_ code: UInt16) -> String {
+        keyNames[code] ?? "Key\(code)"
+    }
+
+    /// True macOS ANSI keycodes (NOT sequential — e.g. kVK_ANSI_5 = 23, _6 = 22).
+    private static let keyNames: [UInt16: String] = [
+        18: "1", 19: "2", 20: "3", 21: "4", 23: "5", 22: "6",
+        26: "7", 28: "8", 25: "9", 29: "0",
+        24: "=", 27: "-",
+        12: "Q", 13: "W", 14: "E", 15: "R", 16: "T", 17: "Y",
+        32: "U", 34: "I", 31: "O", 35: "P",
+        0:  "A", 1:  "S", 2:  "D", 3:  "F", 4:  "H", 5:  "G",
+        38: "J", 40: "K", 37: "L",
+        45: "N", 46: "M",
+        6:  "Z", 7:  "X", 8:  "C", 9:  "V", 11: "B",
+        49: "Space",
+        36: "Return", 53: "Esc", 48: "Tab", 51: "Delete",
+    ]
+}

Sources/Stag/Views/PreferencesWindow.swift

@@ -830,33 +830,7 @@ private struct ShortcutRecorder: View {
     private var displayText: String {
         if isRecording { return "Press shortcut\u{2026}" }
         if current.keyCode == 0 { return "None" }
-        var parts: [String] = []
-        let flags = current.modifierFlags
-        if flags.contains(.control) { parts.append("\u{2303}") }
-        if flags.contains(.option)  { parts.append("\u{2325}") }
-        if flags.contains(.shift)   { parts.append("\u{21E7}") }
-        if flags.contains(.command) { parts.append("\u{2318}") }
-        let key = keyName(current.keyCode)
-        parts.append(key)
-        return parts.joined()
-    }
-
-    private func keyName(_ code: UInt16) -> String {
-        let map: [UInt16: String] = [
-            // True macOS ANSI digit keycodes (NOT sequential).
-            18: "1", 19: "2", 20: "3", 21: "4", 23: "5", 22: "6",
-            26: "7", 28: "8", 25: "9", 29: "0",
-            24: "=", 27: "-",
-            12: "Q", 13: "W", 14: "E", 15: "R", 16: "T", 17: "Y",
-            32: "U", 34: "I", 31: "O", 35: "P",
-            0:  "A", 1:  "S", 2:  "D", 3:  "F", 4:  "H", 5:  "G",
-            38: "J", 40: "K", 37: "L",
-            45: "N", 46: "M",
-            6:  "Z", 7:  "X", 8:  "C", 9:  "V", 11: "B",
-            49: "Space",
-            36: "Return", 53: "Esc", 48: "Tab", 51: "Delete",
-        ]
-        return map[code] ?? "Key\(code)"
+        return current.displayString
     }
 }
 

Tests/StagTests/HotKeyCombinationDisplayTests.swift

@@ -0,0 +1,42 @@
+import XCTest
+import Cocoa
+@testable import Stag
+
+/// Display-string formatting extracted from PreferencesWindow's shortcut row.
+final class HotKeyCombinationDisplayTests: XCTestCase {
+
+    private func combo(_ keyCode: UInt16, _ flags: NSEvent.ModifierFlags) -> HotKeyCombination {
+        HotKeyCombination(keyCode: keyCode, modifiers: flags.rawValue)
+    }
+
+    func testCommandShiftDigit() {
+        // keyCode 18 == "1"; modifiers render in ⌃⌥⇧⌘ order.
+        XCTAssertEqual(combo(18, [.command, .shift]).displayString, "\u{21E7}\u{2318}1")
+    }
+
+    func testModifierOrderingIsControlOptionShiftCommand() {
+        let s = combo(8, [.command, .control, .shift, .option]).displayString  // 8 == "C"
+        XCTAssertEqual(s, "\u{2303}\u{2325}\u{21E7}\u{2318}C")
+    }
+
+    func testNonSequentialDigitKeycodes() {
+        // Regression guard: kVK_ANSI_5 = 23, kVK_ANSI_6 = 22.
+        XCTAssertEqual(HotKeyCombination.keyName(23), "5")
+        XCTAssertEqual(HotKeyCombination.keyName(22), "6")
+    }
+
+    func testUnknownKeycodeFallsBack() {
+        XCTAssertEqual(HotKeyCombination.keyName(99), "Key99")
+        XCTAssertEqual(combo(99, [.command]).displayString, "\u{2318}Key99")
+    }
+
+    func testZeroKeyCodeIsEmpty() {
+        XCTAssertEqual(combo(0, [.command]).displayString, "")
+    }
+
+    func testSpecialKeyLabels() {
+        XCTAssertEqual(HotKeyCombination.keyName(49), "Space")
+        XCTAssertEqual(HotKeyCombination.keyName(36), "Return")
+        XCTAssertEqual(HotKeyCombination.keyName(53), "Esc")
+    }
+}