Support block-based accessibility properties

These block-based variants of the UIAccessibility properties were introduced in iOS 17. Resolves #192.

Sources/AccessibilitySnapshot/Core/Swift/Classes/UIAccessibility+SnapshotAdditions.swift

@@ -20,9 +20,9 @@ extension NSObject {
 
     /// Returns a tuple consisting of the `description` and (optionally) a `hint` that VoiceOver will read for the object.
     func accessibilityDescription(context: AccessibilityHierarchyParser.Context?) -> (description: String, hint: String?) {
-        var accessibilityDescription = accessibilityLabelOverride(for: context) ?? accessibilityLabel ?? ""
+        var accessibilityDescription = accessibilityLabelOverride(for: context) ?? effectiveAccessibilityLabel ?? ""
 
-        var hintDescription = accessibilityHint?.nonEmpty()
+        var hintDescription = effectiveAccessibilityHint?.nonEmpty()
 
         let strings = Strings(locale: accessibilityLanguage)
 
@@ -36,7 +36,7 @@ extension NSObject {
             switch context {
             case let .dataTableCell(row: row, column: column, width: width, height: height, isFirstInRow: isFirstInRow, rowHeaders: rowHeaders, columnHeaders: columnHeaders):
                 let headersDescription = (rowHeaders + columnHeaders).map { header -> String in
-                    switch (header.accessibilityLabel?.nonEmpty(), header.accessibilityValue?.nonEmpty()) {
+                    switch (header.effectiveAccessibilityLabel?.nonEmpty(), header.effectiveAccessibilityValue?.nonEmpty()) {
                     case (nil, nil):
                         return ""
                     case let (.some(label), nil):
@@ -74,7 +74,7 @@ extension NSObject {
             descriptionContainsContext = false
         }
 
-        if let accessibilityValue = accessibilityValue?.nonEmpty(), !hidesAccessibilityValue(for: context) {
+        if let accessibilityValue = effectiveAccessibilityValue?.nonEmpty(), !hidesAccessibilityValue(for: context) {
             if let existingDescription = accessibilityDescription.nonEmpty() {
                 if descriptionContainsContext {
                     accessibilityDescription += " \(accessibilityValue)"
@@ -114,7 +114,7 @@ extension NSObject {
                 traitSpecifiers.append(strings.switchButtonTraitName)
             }
 
-            switch accessibilityValue {
+            switch effectiveAccessibilityValue {
             case "1":
                 traitSpecifiers.append(strings.switchButtonOnStateName)
             case "0":
@@ -229,7 +229,7 @@ extension NSObject {
             }
         }
 
-        let hasHintOnly = (accessibilityHint?.nonEmpty() != nil) && (accessibilityLabel?.nonEmpty() == nil) && (accessibilityValue?.nonEmpty() == nil)
+        let hasHintOnly = (effectiveAccessibilityHint?.nonEmpty() != nil) && (effectiveAccessibilityLabel?.nonEmpty() == nil) && (effectiveAccessibilityValue?.nonEmpty() == nil)
         let hidesAdjustableHint = accessibilityTraits.contains(.notEnabled) || accessibilityTraits.contains(.switchButton) || hasHintOnly
         if accessibilityTraits.contains(.adjustable) && !hidesAdjustableHint {
             if let existingHintDescription = hintDescription?.nonEmpty()?.strippingTrailingPeriod() {
@@ -276,7 +276,47 @@ extension NSObject {
         }
     }
 
-    // MARK: - Private Static Properties
+    // MARK: - Private Properties
+
+    private var effectiveAccessibilityLabel: String? {
+        if #available(iOS 17.0, *) {
+            return accessibilityLabelBlock?() ?? accessibilityLabel
+        } else {
+            return accessibilityLabel
+        }
+    }
+
+    private var effectiveAccessibilityValue: String? {
+        if #available(iOS 17.0, *) {
+            return accessibilityValueBlock?() ?? accessibilityValue
+        } else {
+            return accessibilityValue
+        }
+    }
+
+    private var effectiveAccessibilityHint: String? {
+        if #available(iOS 17.0, *) {
+            return accessibilityHintBlock?() ?? accessibilityHint
+        } else {
+            return accessibilityHint
+        }
+    }
+
+    private var effectiveAccessibilityTraits: UIAccessibilityTraits? {
+        if #available(iOS 17.0, *) {
+            return accessibilityTraitsBlock?() ?? accessibilityTraits
+        } else {
+            return accessibilityTraits
+        }
+    }
+
+    private var effectiveAccessibilityLanguage: String? {
+        if #available(iOS 17.0, *) {
+            return accessibilityLanguageBlock?() ?? accessibilityLanguage
+        } else {
+            return accessibilityLanguage
+        }
+    }
 
     // MARK: - Private