Coverage Summary for Class: TransactionAmountError (com.georgeci.moneysurfer.feature.transaction.creation)

 package com.georgeci.moneysurfer.feature.transaction.creation
 
 /**
  * Pure validation for the transaction amount fields (single amount and both
  * transfer legs). Lives outside the ViewModel so the parsing rules can be
  * unit-tested directly — same split as `InitialBalanceInput` in feature/account.
  */
 object TransactionAmountInput {
 
     /** Digits with at most one decimal separator; no sign, no exponent. */
     private val AMOUNT_PATTERN = Regex("""\d*\.?\d*""")
 
     /**
      * Parses a raw amount (',' normalised to '.') to a [Double], or null when
      * the text is not a plain unsigned decimal — e.g. "1.2.3", "12a", "-5".
      */
     fun parse(amount: String): Double? {
         val normalized = amount.replace(',', '.')
         if (!normalized.matches(AMOUNT_PATTERN)) return null
         return normalized.toDoubleOrNull()
     }
 
     /** Submit gate: the amount parses and is strictly positive. */
     fun isValid(amount: String): Boolean = (parse(amount) ?: return false) > 0.0
 
     /**
      * The inline error to surface for [amount], or null when the field is
      * empty (nothing to complain about yet) or holds a positive amount.
      */
     fun errorFor(amount: String): TransactionAmountError? {
         if (amount.isBlank()) return null
         val parsed = parse(amount) ?: return TransactionAmountError.INVALID_FORMAT
         return if (parsed > 0.0) null else TransactionAmountError.NOT_POSITIVE
     }
 }
 
 /** Validation failures for a transaction amount field. */
 enum class TransactionAmountError { INVALID_FORMAT, NOT_POSITIVE }