A floating point number with all zeros after the point cannot be deserialized as Double or Float

I have a collection where the property price is a kotlin.Float. By chance one document has "price": 2.0" and when inserted in the database, MongoDB shows the value correctly as double but the JSON returned has "price: 2". When deserializing that exact document the runtime throws:

org.bson.BsonInvalidOperationException: readDouble can only be called when CurrentBSONType is DOUBLE, not when CurrentBSONType is INT32.
	at org.bson.AbstractBsonReader.verifyBSONType(AbstractBsonReader.java:690)
	at org.bson.AbstractBsonReader.checkPreconditions(AbstractBsonReader.java:722)
	at org.bson.AbstractBsonReader.readDouble(AbstractBsonReader.java:317)
	at com.github.jershell.kbson.FlexibleDecoder.decodeFloat(BsonFlexibleDecoder.kt:101)
	at kotlinx.serialization.encoding.AbstractDecoder.decodeFloatElement(AbstractDecoder.kt:53)
	at it.belabs.beristo.data.food.Menu$Section$Course$AdditionalIngredient$$serializer.deserialize(Menu.kt)
	at it.belabs.beristo.data.food.Menu$Section$Course$AdditionalIngredient$$serializer.deserialize(Menu.kt:36)

Somehow the price of that document has been interpreted by the library as an INT32 of some sort due to the .0 missing from the MongoDB BSON deserialization. I was not able to find any workaround aside from storing price as String and manage that stuff at runtime, which is awful to say the least.

Not sure if it’s a MongoDB Java library issue or a KMongo one tho.

[zigzago]

Ok but it works also with kotlinx. serialization - see my unit test https://github.com/Litote/kmongo/blob/master/kmongo-core-tests/src/main/kotlin/org/litote/kmongo/issues/Issue232FloatSerialization.kt

[lamba92]

Turns out it was the IntelliJ MongoDB console/driver that converted the item to INT32 when inserting it. When using KMongo to insert the item it is correctly stored as Double.