Avoid possible bugs with truthiness checks for Bool attributes

Related to commit d6a6027.

CHANGELOG.md

@@ -5,6 +5,11 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## [Unreleased] - 
+
+### Fixed
+- Avoid possible bugs with truthiness checks for `Bool` operation attributes
+
 ## [0.14.3] - 2023-10-21
 
 ### Added

src/bill/operations/mixins/set_default_quantity.cr

@@ -5,7 +5,7 @@ module Bill::SetDefaultQuantity
     end
 
     private def set_default_quantity
-      quantity.value = 1 unless quantity.value
+      quantity.value = 1 if quantity.value.nil?
     end
   end
 end

src/bill/operations/mixins/set_default_status.cr

@@ -5,7 +5,7 @@ module Bill::SetDefaultStatus
     end
 
     private def set_default_status
-      return if status.value
+      return unless status.value.nil?
       status.value = {{ T }}Status.new(:draft)
     end
   end

src/bill/operations/mixins/set_finalized_created_at.cr

@@ -5,7 +5,7 @@ module Bill::SetFinalizedCreatedAt
     end
 
     private def set_finalized_created_at
-      return unless created_at.value
+      return if created_at.value.nil?
       created_at.value = Time.utc if {{ T }}Status.now_finalized?(status)
     end
   end

src/bill/operations/refund_payment.cr

@@ -25,7 +25,7 @@ module Bill::RefundPayment
     end
 
     private def set_amount
-      return if amount.value
+      return unless amount.value.nil?
       receipt.try { |receipt| amount.value = receipt.amount }
     end
 
@@ -46,7 +46,7 @@ module Bill::RefundPayment
     end
 
     private def set_default_description
-      return if description.value
+      return unless description.value.nil?
 
       receipt.try do |receipt|
         description.value = Rex.t(
@@ -57,10 +57,10 @@ module Bill::RefundPayment
     end
 
     private def validate_amount_lte_receipt
-      return unless value = amount.value
+      amount.value.try do |value|
+        receipt.try do |receipt|
+          return if value <= receipt.amount
 
-      receipt.try do |receipt|
-        if value > receipt.amount
           amount.add_error Rex.t(
             :"operation.error.refund_exceeds_receipt",
             amount: value,