Add tests for field ordering

playframework · May 11, 2024 · cff4e97 · cff4e97
1 parent 51bd5d6
commit cff4e97
Showing 1 changed file with 10 additions and 0 deletions.
diff --git a/play-json/shared/src/test/scala/play/api/libs/json/JsonSharedSpec.scala b/play-json/shared/src/test/scala/play/api/libs/json/JsonSharedSpec.scala
@@ -28,6 +28,10 @@ class JsonSharedSpec extends AnyWordSpec with Matchers with org.scalatestplus.sc
       (__ \ Symbol("models")).format[Map[String, String]]
   )(Car.apply, c => (c.id, c.models))
 
+  case class Model(m1: Option[String], c: String, z: Option[Double], a: Int, b: Option[String])
+
+  implicit val modelFormat: Format[Model] = Json.format[Model]
+
   def json[T](f: JsonFacade => T) = forAll(Gen.oneOf(Json, Json.configured, Json.using[Json.MacroOptions]))(f)
 
   "JSON" should {
@@ -443,6 +447,12 @@ class JsonSharedSpec extends AnyWordSpec with Matchers with org.scalatestplus.sc
 
       test.toString.mustEqual(js.parse(req).toString) // ).ignoreSpace
     }
+
+    "preserve field ordering" in {
+      val model = Model(Some("foo"), "bar", Some(1.2), 42, Some("baz"))
+      val serialized = Json.stringify(Json.toJson(model))
+      serialized.mustEqual("""{"m1":"foo","c":"bar","z":1.2,"a":42,"b":"baz"}""")
+    }
   }
 
   // ---