Do not attempt to cache based on a signature that uses a Locale (#334)

* Fix a bug where use of autoupdatingCurrentLocale with number formatters resulted in not-autoupdating behavior

* Remove tests for Measurement in package

Author: parkera

Sources/FoundationEssentials/Locale/Locale_Cache.swift

@@ -250,6 +250,15 @@ struct LocaleCache : Sendable {
         lock.withLock { $0.reset() }
     }
 
+    /// For testing of `autoupdatingCurrent` only. If you want to test `current`, create a custom `Locale` with the appropriate settings using `localeAsIfCurrent(name:overrides:disableBundleMatching:)` and use that instead.
+    /// This mutates global state of the current locale, so it is not safe to use in concurrent testing.
+    func resetCurrent(to preferences: LocalePreferences) {
+        lock.withLock {
+            $0.reset()
+            let _ = $0.current(preferences: preferences, cache: true)
+        }
+    }
+
     var current: any _LocaleProtocol {
         var result = lock.withLock {
             $0.current(preferences: nil, cache: false)

Sources/FoundationInternationalization/Formatting/Number/ICUNumberFormatter.swift

@@ -33,23 +33,24 @@ internal func resetAllNumberFormatterCaches() {
 @available(macOS 12.0, iOS 15.0, tvOS 15.0, watchOS 8.0, *)
 internal class ICUNumberFormatterBase {
     internal let uformatter: OpaquePointer
+    /// Stored for testing purposes only
     internal let skeleton: String
 
-    init?(skeleton: String, locale: Locale) {
+    init?(skeleton: String, localeIdentifier: String, preferences: LocalePreferences?) {
         self.skeleton = skeleton
         let ustr = Array(skeleton.utf16)
         var status = U_ZERO_ERROR
-        let formatter = unumf_openForSkeletonAndLocale(ustr, Int32(ustr.count), locale.identifierCapturingPreferences, &status)
-
+        let formatter = unumf_openForSkeletonAndLocale(ustr, Int32(ustr.count), localeIdentifier, &status)
+        
         guard let formatter else {
             return nil
         }
-
+        
         guard status.isSuccess else {
             unumf_close(formatter)
             return nil
         }
-
+        
         uformatter = formatter
     }
 
@@ -246,27 +247,28 @@ internal class ICUNumberFormatterBase {
 final class ICUNumberFormatter : ICUNumberFormatterBase {
     fileprivate struct Signature : Hashable {
         let collection: NumberFormatStyleConfiguration.Collection
-        let locale: Locale
+        let localeIdentifier: String
+        let localePreferences: LocalePreferences?
     }
 
     fileprivate static let cache = FormatterCache<Signature, ICUNumberFormatter?>()
 
     private static func _create(with signature: Signature) -> ICUNumberFormatter? {
         Self.cache.formatter(for: signature) {
-            .init(skeleton: signature.collection.skeleton, locale: signature.locale)
+            .init(skeleton: signature.collection.skeleton, localeIdentifier: signature.localeIdentifier, preferences: signature.localePreferences)
         }
     }
 
     static func create<T: BinaryInteger>(for style: IntegerFormatStyle<T>) -> ICUNumberFormatter? {
-        _create(with: .init(collection: style.collection, locale: style.locale))
+        _create(with: .init(collection: style.collection, localeIdentifier: style.locale.identifierCapturingPreferences, localePreferences: style.locale.prefs))
     }
 
     static func create(for style: Decimal.FormatStyle) -> ICUNumberFormatter? {
-        _create(with: .init(collection: style.collection, locale: style.locale))
+        _create(with: .init(collection: style.collection, localeIdentifier: style.locale.identifierCapturingPreferences, localePreferences: style.locale.prefs))
     }
 
     static func create<T: BinaryFloatingPoint>(for style: FloatingPointFormatStyle<T>) -> ICUNumberFormatter? {
-        _create(with: .init(collection: style.collection, locale: style.locale))
+        _create(with: .init(collection: style.collection, localeIdentifier: style.locale.identifierCapturingPreferences, localePreferences: style.locale.prefs))
     }
 
     func attributedFormat(_ v: Value) -> AttributedString {
@@ -283,7 +285,8 @@ final class ICUCurrencyNumberFormatter : ICUNumberFormatterBase {
     fileprivate struct Signature : Hashable {
         let collection: CurrencyFormatStyleConfiguration.Collection
         let currencyCode: String
-        let locale: Locale
+        let localeIdentifier: String
+        let localePreferences: LocalePreferences?
     }
 
     private static func skeleton(for signature: Signature) -> String {
@@ -301,20 +304,20 @@ final class ICUCurrencyNumberFormatter : ICUNumberFormatterBase {
 
     static private func _create(with signature: Signature) -> ICUCurrencyNumberFormatter? {
         return Self.cache.formatter(for: signature) {
-            .init(skeleton: Self.skeleton(for: signature), locale: signature.locale)
+            .init(skeleton: Self.skeleton(for: signature), localeIdentifier: signature.localeIdentifier, preferences: signature.localePreferences)
         }
     }
 
     static func create<T: BinaryInteger>(for style: IntegerFormatStyle<T>.Currency) -> ICUCurrencyNumberFormatter? {
-        _create(with: .init(collection: style.collection, currencyCode: style.currencyCode, locale: style.locale))
+        _create(with: .init(collection: style.collection, currencyCode: style.currencyCode, localeIdentifier: style.locale.identifierCapturingPreferences, localePreferences: style.locale.prefs))
     }
 
     static func create(for style: Decimal.FormatStyle.Currency) -> ICUCurrencyNumberFormatter? {
-        _create(with: .init(collection: style.collection, currencyCode: style.currencyCode, locale: style.locale))
+        _create(with: .init(collection: style.collection, currencyCode: style.currencyCode, localeIdentifier: style.locale.identifierCapturingPreferences, localePreferences: style.locale.prefs))
     }
 
     static func create<T: BinaryFloatingPoint>(for style: FloatingPointFormatStyle<T>.Currency) -> ICUCurrencyNumberFormatter? {
-        _create(with: .init(collection: style.collection, currencyCode: style.currencyCode, locale: style.locale))
+        _create(with: .init(collection: style.collection, currencyCode: style.currencyCode, localeIdentifier: style.locale.identifierCapturingPreferences, localePreferences: style.locale.prefs))
     }
 
     func attributedFormat(_ v: Value) -> AttributedString {
@@ -330,7 +333,8 @@ final class ICUCurrencyNumberFormatter : ICUNumberFormatterBase {
 final class ICUPercentNumberFormatter : ICUNumberFormatterBase {
     fileprivate struct Signature : Hashable {
         let collection: NumberFormatStyleConfiguration.Collection
-        let locale: Locale
+        let localeIdentifier: String
+        let localePreferences: LocalePreferences?
     }
 
     private static func skeleton(for signature: Signature) -> String {
@@ -346,20 +350,20 @@ final class ICUPercentNumberFormatter : ICUNumberFormatterBase {
 
     private static func _create(with signature: Signature) -> ICUPercentNumberFormatter? {
         return Self.cache.formatter(for: signature) {
-            .init(skeleton: Self.skeleton(for: signature), locale: signature.locale)
+            .init(skeleton: Self.skeleton(for: signature), localeIdentifier: signature.localeIdentifier, preferences: signature.localePreferences)
         }
     }
 
     static func create<T: BinaryInteger>(for style: IntegerFormatStyle<T>.Percent) -> ICUPercentNumberFormatter? {
-        _create(with: .init(collection: style.collection, locale: style.locale))
+        _create(with: .init(collection: style.collection, localeIdentifier: style.locale.identifierCapturingPreferences, localePreferences: style.locale.prefs))
     }
 
     static func create(for style: Decimal.FormatStyle.Percent) -> ICUPercentNumberFormatter? {
-        _create(with: .init(collection: style.collection, locale: style.locale))
+        _create(with: .init(collection: style.collection, localeIdentifier: style.locale.identifierCapturingPreferences, localePreferences: style.locale.prefs))
     }
 
     static func create<T: BinaryFloatingPoint>(for style: FloatingPointFormatStyle<T>.Percent) -> ICUPercentNumberFormatter? {
-        _create(with: .init(collection: style.collection, locale: style.locale))
+        _create(with: .init(collection: style.collection, localeIdentifier: style.locale.identifierCapturingPreferences, localePreferences: style.locale.prefs))
     }
 
     func attributedFormat(_ v: Value) -> AttributedString {
@@ -375,15 +379,16 @@ final class ICUPercentNumberFormatter : ICUNumberFormatterBase {
 final class ICUByteCountNumberFormatter : ICUNumberFormatterBase {
     fileprivate struct Signature : Hashable {
         let skeleton: String
-        let locale: Locale
+        let localeIdentifier: String
+        let localePreferences: LocalePreferences?
     }
 
     fileprivate static let cache = FormatterCache<Signature, ICUByteCountNumberFormatter?>()
 
     static func create(for skeleton: String, locale: Locale) -> ICUByteCountNumberFormatter? {
-        let signature = Signature(skeleton: skeleton, locale: locale)
+        let signature = Signature(skeleton: skeleton, localeIdentifier: locale.identifierCapturingPreferences, localePreferences: locale.prefs)
         return Self.cache.formatter(for: signature) {
-            .init(skeleton: skeleton, locale: locale)
+            .init(skeleton: skeleton, localeIdentifier: locale.identifierCapturingPreferences, preferences: locale.prefs)
         }
     }
 
@@ -433,15 +438,16 @@ final class ICUByteCountNumberFormatter : ICUNumberFormatterBase {
 final class ICUMeasurementNumberFormatter : ICUNumberFormatterBase {
     fileprivate struct Signature : Hashable {
         let skeleton: String
-        let locale: Locale
+        let localeIdentifier: String
+        let localePreferences: LocalePreferences?
     }
 
     fileprivate static let cache = FormatterCache<Signature, ICUMeasurementNumberFormatter?>()
 
     static func create(for skeleton: String, locale: Locale) -> ICUMeasurementNumberFormatter? {
-        let signature = Signature(skeleton: skeleton, locale: locale)
+        let signature = Signature(skeleton: skeleton, localeIdentifier: locale.identifierCapturingPreferences, localePreferences: locale.prefs)
         return Self.cache.formatter(for: signature) {
-            .init(skeleton: skeleton, locale: locale)
+            .init(skeleton: skeleton, localeIdentifier: locale.identifierCapturingPreferences, preferences: locale.prefs)
         }
     }
 

Tests/FoundationInternationalizationTests/Formatting/NumberFormatStyleTests.swift

@@ -441,6 +441,55 @@ final class NumberFormatStyleTests: XCTestCase {
         XCTAssertEqual((-3.14159 as Decimal).formatted(.currency(code:"USD")), currencyStyle.format(-3.14159))
         XCTAssertEqual((-3000.14159 as Decimal).formatted(.currency(code:"USD")), currencyStyle.format(-3000.14159))
     }
+    
+    func test_autoupdatingCurrentChangesFormatResults() {
+        let locale = Locale.autoupdatingCurrent
+        let number = 50_000
+#if FOUNDATION_FRAMEWORK
+        // Measurement is not yet available in the package
+        let measurement = Measurement(value: 0.8, unit: UnitLength.meters)
+#endif
+        let currency = Decimal(123.45)
+        let percent = 54.32
+        let bytes = 1_234_567_890
+        
+        // Get a formatted result from es-ES
+        var prefs = LocalePreferences()
+        prefs.languages = ["es-ES"]
+        prefs.locale = "es_ES"
+        LocaleCache.cache.resetCurrent(to: prefs)
+        let formattedSpanishNumber = number.formatted(.number.locale(locale))
+#if FOUNDATION_FRAMEWORK
+        let formattedSpanishMeasurement = measurement.formatted(.measurement(width: .narrow).locale(locale))
+#endif
+        let formattedSpanishCurrency = currency.formatted(.currency(code: "USD").locale(locale))
+        let formattedSpanishPercent = percent.formatted(.percent.locale(locale))
+        let formattedSpanishBytes = bytes.formatted(.byteCount(style: .decimal).locale(locale))
+        
+        // Get a formatted result from en-US
+        prefs.languages = ["en-US"]
+        prefs.locale = "en_US"
+        LocaleCache.cache.resetCurrent(to: prefs)
+        let formattedEnglishNumber = number.formatted(.number.locale(locale))
+#if FOUNDATION_FRAMEWORK
+        let formattedEnglishMeasurement = measurement.formatted(.measurement(width: .narrow).locale(locale))
+#endif
+        let formattedEnglishCurrency = currency.formatted(.currency(code: "USD").locale(locale))
+        let formattedEnglishPercent = percent.formatted(.percent.locale(locale))
+        let formattedEnglishBytes = bytes.formatted(.byteCount(style: .decimal).locale(locale))
+        
+        // Reset to current preferences before any possibility of failing this test
+        LocaleCache.cache.reset()
+
+        // No matter what 'current' was before this test was run, formattedSpanish and formattedEnglish should be different.
+        XCTAssertNotEqual(formattedSpanishNumber, formattedEnglishNumber)
+#if FOUNDATION_FRAMEWORK
+        XCTAssertNotEqual(formattedSpanishMeasurement, formattedEnglishMeasurement)
+#endif
+        XCTAssertNotEqual(formattedSpanishCurrency, formattedEnglishCurrency)
+        XCTAssertNotEqual(formattedSpanishPercent, formattedEnglishPercent)
+        XCTAssertNotEqual(formattedSpanishBytes, formattedEnglishBytes)
+    }
 }
 
 extension NumberFormatStyleConfiguration.Collection {