refactor: handle null values gracefully in JSON encoders

- Updated JSON encoders for `Date`, `DateTime`, and `ObjectId` to map null values to `Json.Null` using `Option`.

Author: QuadStingray

package.json

@@ -1,7 +1,7 @@
 {
   "name" : "mongodb-driver",
   "organization" : "dev.mongocamp",
-  "version" : "3.0.5.snapshot",
+  "version" : "3.0.5",
   "author" : "[email protected]",
   "license" : "Apache-2.0",
   "type" : "module",

src/main/scala/dev/mongocamp/driver/mongodb/json/CirceSchema.scala

@@ -62,8 +62,12 @@ trait CirceSchema extends CirceProductSchema {
   }
 
   implicit val DateFormat: Encoder[Date] with io.circe.Decoder[Date] = new io.circe.Encoder[Date] with io.circe.Decoder[Date] {
-    override def apply(a: Date): Json = {
-      Encoder.encodeString.apply(a.toInstant.toString)
+    override def apply(d: Date): Json = {
+      Option(d)
+        .map(
+          date => Encoder.encodeString.apply(date.toInstant.toString)
+        )
+        .getOrElse(Json.Null)
     }
 
     override def apply(c: HCursor): Result[Date] = {
@@ -76,8 +80,12 @@ trait CirceSchema extends CirceProductSchema {
   }
 
   implicit val DateTimeFormat: Encoder[DateTime] with io.circe.Decoder[DateTime] = new io.circe.Encoder[DateTime] with io.circe.Decoder[DateTime] {
-    override def apply(a: DateTime): Json = {
-      Encoder.encodeString.apply(a.toInstant.toString)
+    override def apply(d: DateTime): Json = {
+      Option(d)
+        .map(
+          date => Encoder.encodeString.apply(date.toInstant.toString)
+        )
+        .getOrElse(Json.Null)
     }
 
     override def apply(c: HCursor): Result[DateTime] = {
@@ -90,8 +98,12 @@ trait CirceSchema extends CirceProductSchema {
   }
 
   implicit val ObjectIdFormat: Encoder[ObjectId] with io.circe.Decoder[ObjectId] = new io.circe.Encoder[ObjectId] with io.circe.Decoder[ObjectId] {
-    override def apply(a: ObjectId): Json = {
-      Encoder.encodeString.apply(a.toHexString)
+    override def apply(o: ObjectId): Json = {
+      Option(o)
+        .map(
+          o => Encoder.encodeString.apply(o.toHexString)
+        )
+        .getOrElse(Json.Null)
     }
 
     override def apply(c: HCursor): Result[ObjectId] = {