Merge pull request groue#1729 from groue/dev/issue-1728

Deprecate Date coding strategies based on DateFormatter

Author: groue

GRDB/Record/EncodableRecord.swift

@@ -524,7 +524,12 @@ public enum DatabaseDataEncodingStrategy: Sendable {
 ///     var creationDate: Date
 /// }
 /// ```
-public enum DatabaseDateEncodingStrategy: Sendable {
+public enum DatabaseDateEncodingStrategy: @unchecked Sendable {
+    // @unchecked Sendable because of `DateFormatter`, which lost its
+    // `Sendable` conformance with Xcode 16.3. See
+    // <https://github.com/swiftlang/swift/issues/78635>.
+    // TODO GRDB8: remove @unchecked when the .formatted case has been removed.
+    
     /// The strategy that uses formatting from the Date structure.
     ///
     /// It encodes dates using the format "YYYY-MM-DD HH:MM:SS.SSS" in the
@@ -551,6 +556,7 @@ public enum DatabaseDateEncodingStrategy: Sendable {
     case iso8601
 
     /// Encodes a String, according to the provided formatter
+    @available(*, deprecated, message: "Use .custom and a Date.FormatStyle instead.")
     case formatted(DateFormatter)
 
     /// Encodes the result of the user-provided function

GRDB/Record/FetchableRecord.swift

@@ -929,7 +929,12 @@ public enum DatabaseDataDecodingStrategy: Sendable {
 ///         var name: String
 ///         var registrationDate: Date // decoded from epoch timestamp
 ///     }
-public enum DatabaseDateDecodingStrategy: Sendable {
+public enum DatabaseDateDecodingStrategy: @unchecked Sendable {
+    // @unchecked Sendable because of `DateFormatter`, which lost its
+    // `Sendable` conformance with Xcode 16.3. See
+    // <https://github.com/swiftlang/swift/issues/78635>.
+    // TODO GRDB8: remove @unchecked when the .formatted case has been removed.
+    
     /// The strategy that uses formatting from the Date structure.
     ///
     /// It decodes numeric values as a number of seconds since Epoch
@@ -963,6 +968,7 @@ public enum DatabaseDateDecodingStrategy: Sendable {
     case iso8601
 
     /// Decodes a String, according to the provided formatter
+    @available(*, deprecated, message: "Use .custom and a Date.FormatStyle instead.")
     case formatted(DateFormatter)
 
     /// Decodes according to the user-provided function.

Tests/GRDBTests/DatabaseDateDecodingStrategyTests.swift

@@ -26,6 +26,7 @@ private enum StrategyIso8601: StrategyProvider {
     static let strategy: DatabaseDateDecodingStrategy = .iso8601
 }
 
+@available(*, deprecated)
 private enum StrategyFormatted: StrategyProvider {
     static let strategy: DatabaseDateDecodingStrategy = .formatted({
         let formatter = DateFormatter()
@@ -418,6 +419,7 @@ extension DatabaseDateDecodingStrategyTests {
 // MARK: - formatted(DateFormatter)
 
 extension DatabaseDateDecodingStrategyTests {
+    @available(*, deprecated)
     func testFormatted() throws {
         try makeDatabaseQueue().read { db in
             var calendar = Calendar(identifier: .gregorian)

Tests/GRDBTests/DatabaseDateEncodingStrategyTests.swift

@@ -30,6 +30,7 @@ private enum StrategyIso8601: StrategyProvider {
     static let strategy: DatabaseDateEncodingStrategy = .iso8601
 }
 
+@available(*, deprecated)
 private enum StrategyFormatted: StrategyProvider {
     static let strategy: DatabaseDateEncodingStrategy = .formatted({
         let formatter = DateFormatter()
@@ -197,6 +198,7 @@ extension DatabaseDateEncodingStrategyTests {
 // MARK: - formatted(DateFormatter)
 
 extension DatabaseDateEncodingStrategyTests {
+    @available(*, deprecated)
     func testFormatted() throws {
         try testNullEncoding(strategy: StrategyFormatted.self)