add transaction value constraint

2 files changed, 2 insertions, 1 deletions

diff --git a/lib/handler.ml b/lib/handler.ml
index 4babe6e..c02ed71 100644
--- a/lib/handler.ml
+++ b/lib/handler.ml
@@ -78,6 +78,7 @@ let get_balance client_id (db_pool : Query.pool) (_request : Request.t) =
                `Assoc [ "total", total; "data_extrato", date; "limite", limit ]
              in
              let t =
+               (* NOTE: Talvez isso aqui não seja uma boa ideia *)
                Result.fold ~ok:Fun.id ~error:(fun _ -> [])
                @@ Query.transactions client_id conn
              in
diff --git a/lib/operation.ml b/lib/operation.ml
index bce6ac2..54962fd 100644
--- a/lib/operation.ml
+++ b/lib/operation.ml
@@ -47,7 +47,7 @@ let decoder : transaction_op Utils.Decoder.decoder =
     <|> literal "d" *> return (fun p -> `Debit p)
   in
   (fun value transaction_type description -> transaction_type { value; description })
-  <$> ("valor" <: int)
+  <$> ("valor" <: (int >>= fun x -> if x >= 0 then return x else fail))
   <*> ("tipo" <: transaction_type_decoder)
   <*> ("descricao"
        <: (string