Fix approximateArrivalTimestamp decoder (#367)

Co-authored-by: Eric Meisel <[email protected]>

feral/src/main/scala/kinesis4cats/consumer/feral/KinesisStreamEvent.scala

@@ -50,11 +50,13 @@ final case class KinesisStreamRecordPayload(
 
 object KinesisStreamRecordPayload {
   implicit private val instantCirceDecoder: Decoder[Instant] =
-    Decoder.decodeBigDecimal.emapTry { millis =>
+    Decoder.decodeBigDecimal.emapTry { secondsDecimal =>
       def round(x: BigDecimal) = x.setScale(0, BigDecimal.RoundingMode.DOWN)
       Try {
-        val seconds = round(millis / 1000).toLongExact
-        val nanos = round((millis % 1000) * 1e6).toLongExact
+        val roundedSecondsDecimal = round(secondsDecimal)
+        val seconds = roundedSecondsDecimal.toLongExact
+        val nanos =
+          round((secondsDecimal - roundedSecondsDecimal) * 1e9).toLongExact
         Instant.ofEpochSecond(seconds, nanos)
       }
     }

feral/src/test/scala/kinesis4cats/consumer/feral/KinesisStreamRecordSpec.scala

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2023-2023 etspaceman
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package kinesis4cats.consumer
+
+import java.time.Instant
+
+import io.circe.parser.decode
+import scodec.bits.ByteVector
+
+import kinesis4cats.consumer.feral.KinesisStreamRecord
+import kinesis4cats.consumer.feral.KinesisStreamRecordPayload
+
+class KinesisStreamRecordSpec extends munit.ScalaCheckSuite {
+  test("It should parse the event correctly from JSON") {
+    val recordJson = """
+    {
+        "kinesis": {
+            "kinesisSchemaVersion": "1.0",
+            "partitionKey": "1",
+            "sequenceNumber": "49590338271490256608559692538361571095921575989136588898",
+            "data": "SGVsbG8sIHRoaXMgaXMgYSB0ZXN0Lg==",
+            "approximateArrivalTimestamp": 1723739794.987
+        },
+        "eventSource": "aws:kinesis",
+        "eventVersion": "1.0",
+        "eventID": "shardId-000000000006:49590338271490256608559692538361571095921575989136588898",
+        "eventName": "aws:kinesis:record",
+        "invokeIdentityArn": "arn:aws:iam::123456789012:role/lambda-role",
+        "awsRegion": "us-east-2",
+        "eventSourceARN": "arn:aws:kinesis:us-east-2:123456789012:stream/lambda-stream"
+    }
+    """
+
+    val record = KinesisStreamRecord(
+      awsRegion = "us-east-2",
+      eventID =
+        "shardId-000000000006:49590338271490256608559692538361571095921575989136588898",
+      eventName = "aws:kinesis:record",
+      eventSource = "aws:kinesis",
+      eventSourceArn =
+        "arn:aws:kinesis:us-east-2:123456789012:stream/lambda-stream",
+      eventVersion = "1.0",
+      invokeIdentityArn = "arn:aws:iam::123456789012:role/lambda-role",
+      kinesis = KinesisStreamRecordPayload(
+        approximateArrivalTimestamp =
+          Instant.ofEpochSecond(1723739794L, 987000000L),
+        data = ByteVector.fromValidBase64("SGVsbG8sIHRoaXMgaXMgYSB0ZXN0Lg=="),
+        kinesisSchemaVersion = "1.0",
+        partitionKey = "1",
+        encryptionType = None,
+        sequenceNumber =
+          "49590338271490256608559692538361571095921575989136588898"
+      )
+    )
+
+    val parsedRecord = decode[KinesisStreamRecord](recordJson)
+    assertEquals(parsedRecord, Right(record))
+  }
+}