stacksafe play -> circe AST conversion

johanmast · Jan 31, 2023 · 8858fd0 · 8858fd0
1 parent 6b81358
commit 8858fd0
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Showing 3 changed files with 59 additions and 24 deletions.
diff --git a/play-json-circe/src/main/scala/com/evolutiongaming/util/PlayCirceAstConversions.scala b/play-json-circe/src/main/scala/com/evolutiongaming/util/PlayCirceAstConversions.scala
@@ -1,5 +1,6 @@
 package com.evolutiongaming.util
 
+import cats.Eval
 import io.circe.{Json => CirceJson}
 import play.api.libs.{json => PlayJson}
 
@@ -14,28 +15,41 @@ object PlayCirceAstConversions {
       jsonObject = o => PlayJson.JsObject(o.toIterable.map { case (k, v) => (k, circeToPlay(v)) }.toSeq),
     )
 
-  def playToCirce(value: PlayJson.JsValue): CirceJson =
-    value match {
-      case PlayJson.JsNull =>
-        CirceJson.Null
-
-      case PlayJson.JsTrue =>
-        CirceJson.True
-
-      case PlayJson.JsFalse =>
-        CirceJson.False
-
-      case PlayJson.JsNumber(value) =>
-        CirceJson.fromBigDecimal(value)
-
-      case PlayJson.JsString(value) =>
-        CirceJson.fromString(value)
-
-      case PlayJson.JsArray(value) =>
-        CirceJson.fromValues(value.map(playToCirce))
-
-      case PlayJson.JsObject(value) =>
-        CirceJson.fromFields(value.iterator.map { case (k, v) => (k, playToCirce(v)) }.to(Iterable))
-    }
+  def playToCirce(value: PlayJson.JsValue): CirceJson = {
+    def inner(value: Eval[PlayJson.JsValue]): Eval[CirceJson] =
+      value.flatMap {
+        case PlayJson.JsNull =>
+          Eval.now(CirceJson.Null)
+
+        case PlayJson.JsTrue =>
+          Eval.now(CirceJson.True)
+
+        case PlayJson.JsFalse =>
+          Eval.now(CirceJson.False)
+
+        case PlayJson.JsNumber(value) =>
+          Eval.now(CirceJson.fromBigDecimal(value))
+
+        case PlayJson.JsString(value) =>
+          Eval.now(CirceJson.fromString(value))
+
+        case PlayJson.JsArray(values) =>
+          if (values.isEmpty)
+            Eval.now(CirceJson.arr())
+          else
+            values.map(v => inner(Eval.now(v)))
+              .foldLeft(Eval.now(Vector.empty[CirceJson]))((acc, v) => v.flatMap(v => acc.map(_ :+ v)))
+              .map(CirceJson.fromValues)
+
+        case PlayJson.JsObject(value) =>
+          Eval.defer {
+            value.view.map { case (k, v) =>
+              inner(Eval.now(v)).map(k -> _)
+            }.foldLeft(Eval.now(Map.empty[String, CirceJson]))((acc, v) => v.flatMap(v => acc.map(_ + v)))
+              .map(CirceJson.fromFields)
+          }
+      }
+    inner(Eval.now(value)).value
+  }
 
 }
diff --git a/...ng/util/PlayCirceAstConversionsSpec.scala → ...il/PlayCirceAstConversionsSmokeSpec.scala b/...ng/util/PlayCirceAstConversionsSpec.scala → ...il/PlayCirceAstConversionsSmokeSpec.scala
@@ -7,7 +7,7 @@ import play.api.libs.{json => play}
 import org.scalatest.prop.TableDrivenPropertyChecks
 
 
-class PlayCirceAstConversionsSpec extends AnyFreeSpec with TableDrivenPropertyChecks with Matchers {
+class PlayCirceAstConversionsSmokeSpec extends AnyFreeSpec with TableDrivenPropertyChecks with Matchers {
 
   "Play to/from Circe AST conversions" in {
     forAll {

diff --git a/...irce/src/test/scala/com/evolutiongaming/util/PlayCirceAstConversionsStackSafetySpec.scala b/...irce/src/test/scala/com/evolutiongaming/util/PlayCirceAstConversionsStackSafetySpec.scala
@@ -0,0 +1,21 @@
+package com.evolutiongaming.util
+
+import com.evolutiongaming.util.PlayCirceAstConversions._
+import org.scalatest.freespec.AnyFreeSpec
+import org.scalatest.matchers.should.Matchers
+import org.scalatest.prop.TableDrivenPropertyChecks
+import play.api.libs.json.{JsObject, Json}
+
+class PlayCirceAstConversionsStackSafetySpec extends AnyFreeSpec with TableDrivenPropertyChecks with Matchers {
+  "Play to Circe AST conversion" - {
+    "can handle deeply nested structures" in {
+      val playJson = (1 to 100000).foldLeft(JsObject.empty)((o, _) => Json.obj("n" -> o))
+      assert(playToCirce(playJson).isObject)
+    }
+
+    "can handle long arrays" in {
+      val playJson = Json.arr(1 to 100000)
+      assert(playToCirce(playJson).isArray)
+    }
+  }
+}