Support DynamoDB's UpdateItemRequest (#288)

* Add decodeItemResponse()

* Use Long.MaxValue instead of magic number

Author: saeltz

src/main/scala/scynamo/Scynamo.scala

@@ -1,7 +1,7 @@
 package scynamo
 
 import cats.data.EitherNec
-import software.amazon.awssdk.services.dynamodb.model.{GetItemResponse, QueryResponse, ScanResponse}
+import software.amazon.awssdk.services.dynamodb.model.{GetItemResponse, QueryResponse, ScanResponse, UpdateItemResponse}
 import cats.syntax.all._
 
 import scala.jdk.CollectionConverters._
@@ -14,10 +14,15 @@ trait ScynamoFunctions {
     else
       Right(None)
 
+  def decodeUpdateItemResponse[A: ObjectScynamoDecoder](response: UpdateItemResponse): EitherNec[ScynamoDecodeError, Option[A]] =
+    if (response.hasAttributes)
+      ObjectScynamoDecoder[A].decodeMap(response.attributes()).map(Some(_))
+    else
+      Right(None)
+
   def decodeQueryResponse[A: ObjectScynamoDecoder](response: QueryResponse): EitherNec[ScynamoDecodeError, List[A]] =
     response.items().asScala.toList.traverse(ObjectScynamoDecoder[A].decodeMap(_))
 
   def decodeScanResponse[A: ObjectScynamoDecoder](response: ScanResponse): EitherNec[ScynamoDecodeError, List[A]] =
     response.items().asScala.toList.traverse(ObjectScynamoDecoder[A].decodeMap(_))
-
 }

src/test/scala/scynamo/ScynamoCodecProps.scala

@@ -82,15 +82,15 @@ class ScynamoCodecProps extends Properties("ScynamoCodec") {
 
   propertyWithSeed("decode.encode === id (option)", propertySeed) = Prop.forAll { value: Option[Int] => decodeAfterEncodeIsIdentity(value) }
 
-  propertyWithSeed("decode.encode === id (finite duration)", propertySeed) =
-    Prop.forAll(Gen.chooseNum(-9223372036854775807L, 9223372036854775807L)) { value =>
+  propertyWithSeed("decode.encode === id (finite duration)", propertySeed) = Prop.forAll(Gen.chooseNum(Long.MinValue + 1, Long.MaxValue)) {
+    value: Long =>
       decodeAfterEncodeIsIdentity(Duration.fromNanos(value))
-    }
+  }
 
-  propertyWithSeed("decode.encode === id (duration)", propertySeed) =
-    Prop.forAll(Gen.chooseNum(-9223372036854775807L, 9223372036854775807L)) { value =>
+  propertyWithSeed("decode.encode === id (duration)", propertySeed) = Prop.forAll(Gen.chooseNum(Long.MinValue + 1, Long.MaxValue)) {
+    value: Long =>
       decodeAfterEncodeIsIdentity(Duration.fromNanos(value): Duration)
-    }
+  }
 
   propertyWithSeed("decode.encode === id (java duration)", propertySeed) = Prop.forAll { value: Long =>
     decodeAfterEncodeIsIdentity(java.time.Duration.ofNanos(value))

src/test/scala/scynamo/ScynamoTest.scala

@@ -17,6 +17,15 @@ class ScynamoTest extends UnitTest {
       result should ===(Right(None))
     }
 
+    "return None if the update item response has no item" in {
+      val response = UpdateItemResponse.builder().build()
+      val result = for {
+        result <- Scynamo.decodeUpdateItemResponse[Map[String, AttributeValue]](response)
+      } yield result
+
+      result should ===(Right(None))
+    }
+
     "return an empty List if the query response has no items" in {
       val response = QueryResponse.builder().build()
 
@@ -37,7 +46,7 @@ class ScynamoTest extends UnitTest {
       result should ===(Right(List.empty))
     }
 
-    "return the decoded result if it has an item that is well formed" in {
+    "return the decoded get item result if it has an item that is well formed" in {
       val input = Map("foo" -> "bar")
 
       val result = for {
@@ -49,6 +58,18 @@ class ScynamoTest extends UnitTest {
       result should ===(Right(Some(input)))
     }
 
+    "return the decoded update item result if it has an item that is well formed" in {
+      val input = Map("foo" -> "bar")
+
+      val result = for {
+        encodedInput <- input.encodedMap
+        response = UpdateItemResponse.builder().attributes(encodedInput).build()
+        result <- Scynamo.decodeUpdateItemResponse[Map[String, String]](response)
+      } yield result
+
+      result should ===(Right(Some(input)))
+    }
+
     "return the decoded query result if it has multiple items that are well formed" in {
       val input1 = Map("foo" -> "bar")
       val input2 = Map("Miami" -> "Ibiza")