Address various warnings across the project

Sources/FoundationInternationalization/Locale/Locale_ICU.swift

@@ -1209,8 +1209,8 @@ internal final class _LocaleICU: _LocaleProtocol, Sendable {
                     }
                 }
 
-                // Check prefs
-                if let firstWeekdayPref = prefs?.firstWeekday {
+                // Check prefs. The value doesn't matter here - we check it again in the `forceFirstWeekday` function, and it is immutable.
+                if prefs?.firstWeekday != nil {
                     let calendarId = calendarIdentifier
                     if let first = forceFirstWeekday(calendarId) {
                         state.firstDayOfWeek = first

Sources/FoundationInternationalization/Locale/Locale_ObjC.swift

@@ -308,7 +308,10 @@ internal class _NSSwiftLocale: _NSLocaleBridge, @unchecked Sendable {
             switch locale.temperatureUnit {
             case .celsius: return NSLocaleTemperatureUnitCelsius
             case .fahrenheit: return NSLocaleTemperatureUnitFahrenheit
+#if !FOUNDATION_FRAMEWORK
+            // On non-framework builds, the enum is non-closed and `package` visibility, so we need a default
             default: return NSLocaleTemperatureUnitCelsius
+#endif
             }
         case .decimalSeparator: return self.decimalSeparator
         case .groupingSeparator: return self.groupingSeparator

Sources/FoundationInternationalization/TimeZone/TimeZone_ICU.swift

@@ -222,6 +222,12 @@ internal final class _TimeZoneICU: _TimeZoneProtocol, Sendable {
                 return Self.timeZoneDisplayName(for: c, timeZoneName: identifier, localeName: locID, isShort: false, isGeneric: true, isDaylight: false)
             case .shortGeneric:
                 return Self.timeZoneDisplayName(for: c, timeZoneName: identifier, localeName: locID, isShort: true, isGeneric: true, isDaylight: false)
+#if FOUNDATION_FRAMEWORK
+                // We only need this when building in ObjC mode, when the enum comes from a .h
+            @unknown default:
+                // Use standard style
+                return Self.timeZoneDisplayName(for: c, timeZoneName: identifier, localeName: locID, isShort: false, isGeneric: false, isDaylight: false)
+#endif
             }
         }
     }

Tests/FoundationEssentialsTests/AttributedString/AttributedStringIndexValidityTests.swift

@@ -140,7 +140,7 @@ final class AttributedStringIndexValidityTests: XCTestCase {
     }
 
     public func testMutationInvalidation() {
-        func checkInPlace(_ mutation: (inout AttributedString) -> (), file: StaticString = #file, line: UInt = #line) {
+        func checkInPlace(_ mutation: (inout AttributedString) -> (), file: StaticString = #filePath, line: UInt = #line) {
             var str = AttributedString("Hello World")
             let idxA = str.startIndex
             let idxB = str.index(afterCharacter: idxA)
@@ -158,7 +158,7 @@ final class AttributedStringIndexValidityTests: XCTestCase {
             XCTAssertFalse(RangeSet(idxA ..< idxB).isValid(within: str), "Initial range set was valid in in-place mutated", file: file, line: line)
         }
 
-        func checkCopy(_ mutation: (inout AttributedString) -> (), file: StaticString = #file, line: UInt = #line) {
+        func checkCopy(_ mutation: (inout AttributedString) -> (), file: StaticString = #filePath, line: UInt = #line) {
             let str = AttributedString("Hello World")
             let idxA = str.startIndex
             let idxB = str.index(afterCharacter: idxA)
@@ -185,7 +185,7 @@ final class AttributedStringIndexValidityTests: XCTestCase {
             XCTAssertFalse(RangeSet(idxA ..< idxB).isValid(within: copy), "Initial range set was valid in copy", file: file, line: line)
         }
 
-        func check(_ mutation: (inout AttributedString) -> (), file: StaticString = #file, line: UInt = #line) {
+        func check(_ mutation: (inout AttributedString) -> (), file: StaticString = #filePath, line: UInt = #line) {
             checkInPlace(mutation, file: file, line: line)
             checkCopy(mutation, file: file, line: line)
         }

Tests/FoundationEssentialsTests/AttributedString/AttributedStringTests.swift

@@ -1882,7 +1882,7 @@ E {
         func check<T: Equatable>(
             _ a: some Sequence<T>,
             _ b: some Sequence<T>,
-            file: StaticString = #file, line: UInt = #line
+            file: StaticString = #filePath, line: UInt = #line
         ) {
             XCTAssertTrue(
                 a.elementsEqual(b),

Tests/FoundationEssentialsTests/DataIOTests.swift

@@ -185,6 +185,7 @@ class DataIOTests : XCTestCase {
 
 #if FOUNDATION_FRAMEWORK
     // String(contentsOf:) is not available outside the framework yet
+    @available(*, deprecated)
     func test_emptyFileString() {
         let data = Data()
         let url = testURL()

Tests/FoundationEssentialsTests/StringTests.swift

@@ -1319,7 +1319,7 @@ final class StringTests : XCTestCase {
 
     }
 
-    func verifyEncoding(_ encoding: String._Encoding, valid: [String], invalid: [String], file: StaticString = #file, line: UInt = #line) throws {
+    func verifyEncoding(_ encoding: String._Encoding, valid: [String], invalid: [String], file: StaticString = #filePath, line: UInt = #line) throws {
         for string in valid {
             let data = try XCTUnwrap(string.data(using: encoding), "Failed to encode \(string.debugDescription)", file: file, line: line)
             XCTAssertNotNil(String(data: data, encoding: encoding), "Failed to decode \(data) (\(string.debugDescription))", file: file, line: line)

Tests/FoundationInternationalizationTests/DateComponentsTests.swift

@@ -141,8 +141,8 @@ final class DateComponentsTests : XCTestCase {
 extension DateComponentsTests {
     func date(from string: String, nanoseconds: Int? = nil) -> Date {
         let d = try! Date(string, strategy: Date.ParseStrategy(format: "\(year: .extended(minimumLength: 4))-\(month: .twoDigits)-\(day: .twoDigits) \(hour: .twoDigits(clock: .twentyFourHour, hourCycle: .zeroBased)):\(minute: .twoDigits):\(second: .twoDigits) \(timeZone: .iso8601(.short))", locale: Locale(identifier: "en_US"), timeZone: TimeZone.gmt))
-        if let nanoseconds {
-            var comps = Calendar(identifier: .gregorian).dateComponents([.era, .year, .month, .day, .hour, .minute, .second, .nanosecond, .weekday, .weekdayOrdinal, .quarter, .weekOfMonth, .weekOfYear, .yearForWeekOfYear, .timeZone, .calendar], from: d)
+        if nanoseconds != nil {
+            let comps = Calendar(identifier: .gregorian).dateComponents([.era, .year, .month, .day, .hour, .minute, .second, .nanosecond, .weekday, .weekdayOrdinal, .quarter, .weekOfMonth, .weekOfYear, .yearForWeekOfYear, .timeZone, .calendar], from: d)
             return Calendar(identifier: .gregorian).date(from: comps)!
         }
         return d

Tests/FoundationInternationalizationTests/Formatting/DateFormatStyleTests.swift

@@ -712,7 +712,7 @@ final class DateAttributedFormatStyleTests : XCTestCase {
 
         func test(dateStyle: Date.FormatStyle.DateStyle, timeStyle: Date.FormatStyle.TimeStyle, dateFormatOverride: [Date.FormatStyle.DateStyle: String], expected: [Segment], file: StaticString = #filePath, line: UInt = #line) {
             let locale = Locale.localeAsIfCurrent(name: enUS, overrides: .init(dateFormats: dateFormatOverride))
-            let style = Date.FormatStyle(date: dateStyle, time: timeStyle, locale: locale, calendar: Calendar(identifier: .gregorian), timeZone: TimeZone(identifier: "PST")!, capitalizationContext: .standalone).attributed
+            let style = Date.FormatStyle(date: dateStyle, time: timeStyle, locale: locale, calendar: Calendar(identifier: .gregorian), timeZone: TimeZone(identifier: "PST")!, capitalizationContext: .standalone).attributedStyle
             XCTAssertEqual(style.format(date), expected.attributedString, file: file, line: line)
         }
 

Tests/FoundationInternationalizationTests/Formatting/NumberFormatStyleTests.swift

@@ -597,7 +597,7 @@ final class NumberFormatStyleTests: XCTestCase {
 
     func testCurrency_Codable() throws {
         let gbpInUS = Decimal.FormatStyle.Currency(code: "GBP", locale: enUSLocale)
-        let encoded = try JSONEncoder().encode(gbpInUS)
+        let _ = try JSONEncoder().encode(gbpInUS)
         // Valid JSON presentation of the format style
         let previouslyEncoded = """
         {