feat: add JsonPatch structure and unit tests

zio-schema-json/shared/src/main/scala/zio/schema/json/JsonPatch.scala

@@ -0,0 +1,43 @@
+package zio.schema.json
+
+import zio.schema.DynamicValue
+
+sealed trait JsonPatch {
+
+  def apply(target: DynamicValue): Either[String, DynamicValue] = this match {
+    case JsonPatch.Add(path, value) =>
+      val key = path.stripPrefix("/")
+      if (key == "") {
+        Left("path cannot be empty")
+      } else {
+        target match {
+          case DynamicValue.Record(id, fields) =>
+            Right(DynamicValue.Record(id, fields.updated(key, value)))
+          case _ =>
+            Left("expected record")
+        }
+      }
+
+    case JsonPatch.Remove(path) =>
+      val key = path.stripPrefix("/")
+      if (key == "") {
+        Left("path cannot be empty")
+      } else {
+        target match {
+          case DynamicValue.Record(id, fields) =>
+            if (fields.contains(key)) {
+              Right(DynamicValue.Record(id, fields - key))
+            } else {
+              Left(s"path $key not found")
+            }
+          case _ =>
+            Left("expected record")
+        }
+      }
+  }
+}
+
+object JsonPatch {
+  final case class Add(path: String, value: DynamicValue) extends JsonPatch
+  final case class Remove(path: String)                   extends JsonPatch
+}

zio-schema-json/shared/src/test/scala/zio/schema/json/JsonPatchSpec.scala

@@ -0,0 +1,42 @@
+package zio.schema.json
+
+import scala.collection.immutable.ListMap
+
+import zio.schema.{ DynamicValue, TypeId }
+import zio.test._
+
+object JsonPatchSpec extends ZIOSpecDefault {
+  override def spec: Spec[Any, Any] = suite("JsonPatch Spec")(
+    test("Add: should add field to record") {
+      val user   = TypeId.parse("User")
+      val data   = ListMap("name" -> DynamicValue("Akshaya"))
+      val record = DynamicValue.Record(user, data)
+
+      val patch  = JsonPatch.Add("/age", DynamicValue(25))
+      val result = patch.apply(record)
+
+      val expectedData = ListMap("name" -> DynamicValue("Akshaya"), "age" -> DynamicValue(25))
+      val expected     = DynamicValue.Record(user, expectedData)
+
+      assertTrue(result == Right(expected))
+    },
+    test("Remove: should remove field from record") {
+      val user   = TypeId.parse("User")
+      val data   = ListMap("name" -> DynamicValue("Akshaya"))
+      val record = DynamicValue.Record(user, data)
+
+      val patch  = JsonPatch.Remove("/name")
+      val result = patch.apply(record)
+
+      val expected = DynamicValue.Record(user, ListMap.empty[String, DynamicValue])
+
+      assertTrue(result == Right(expected))
+    },
+    test("Failure: target is not a record") {
+      val patch  = JsonPatch.Remove("/any")
+      val result = patch.apply(DynamicValue("random-string"))
+
+      assertTrue(result == Left("expected record"))
+    }
+  )
+}