Enable customizing date and data property encoding

We were unintentionally bypassing the encoder when converting properties to
strings, which broke things like JSONEncoder.dateEncodingStrategy.

CHANGELOG.md

@@ -11,6 +11,9 @@ x.y.z Release notes (yyyy-MM-dd)
   `Sendable` annotations ([PR #8435](https://github.com/realm/realm-swift/pull/8435)).
 * `Realm.Error.subscriptionFailed` was reported with the incorrect error
   domain, making it impossible to catch (since v10.42.2, [PR #8435](https://github.com/realm/realm-swift/pull/8435)).
+* `@Persisted`'s Encodable implementation did not allow the encoder to
+  customize the encoding of values, which broke things like JSONEncoder's
+  `dateEncodingStrategy` ([#8425](https://github.com/realm/realm-swift/issues/8425)).
 
 ### Compatibility
 * Realm Studio: 14.0.1 or later.

RealmSwift/Decimal128.swift

@@ -103,7 +103,8 @@ extension Decimal128: Encodable {
     ///
     /// - Parameter encoder: The encoder to write data to.
     public func encode(to encoder: Encoder) throws {
-        try self.stringValue.encode(to: encoder)
+        var container = encoder.singleValueContainer()
+        try container.encode(stringValue)
     }
 }
 

RealmSwift/ObjectId.swift

@@ -90,7 +90,8 @@ extension ObjectId: Encodable {
     ///
     /// - Parameter encoder: The encoder to write data to.
     public func encode(to encoder: Encoder) throws {
-        try self.stringValue.encode(to: encoder)
+        var container = encoder.singleValueContainer()
+        try container.encode(stringValue)
     }
 }
 

RealmSwift/Optional.swift

@@ -83,7 +83,8 @@ extension RealmOptional: Codable where Value: Codable, Value: _RealmSchemaDiscov
     }
 
     public func encode(to encoder: Encoder) throws {
-        try self.value.encode(to: encoder)
+        var container = encoder.singleValueContainer()
+        try container.encode(value)
     }
 }
 

RealmSwift/PersistedProperty.swift

@@ -238,13 +238,14 @@ extension Persisted: Decodable where Value: Decodable {
 
 extension Persisted: Encodable where Value: Encodable {
     public func encode(to encoder: Encoder) throws {
+        var container = encoder.singleValueContainer()
         switch storage {
         case .unmanaged(let value, _, _):
-            try value.encode(to: encoder)
+            try container.encode(value)
         case .unmanagedObserved(let value, _):
-            try value.encode(to: encoder)
+            try container.encode(value)
         case .unmanagedNoDefault:
-            try Value._rlmDefaultValue().encode(to: encoder)
+            try container.encode(Value._rlmDefaultValue())
         default:
             // We need a reference to the parent object to be able to read from
             // a managed property. There's probably a way to do this with some

RealmSwift/RealmProperty.swift

@@ -73,7 +73,8 @@ extension RealmProperty: Codable where Value: Codable {
     }
 
     public func encode(to encoder: Encoder) throws {
-        try self.value.encode(to: encoder)
+        var container = encoder.singleValueContainer()
+        try container.encode(value)
     }
 }