Merge pull request #58 from DEFRA/bugfix/dev-bugs

00697349-net carbon saving field should accept negative numbers

Author: mohassinmp

src/common/schemas/project/carbon.js

@@ -7,6 +7,12 @@ const MAX_COST_DIGITS = 18
 const MAX_HEXDIGEST_LENGTH = 255
 const DECIMAL_REGEX = /^\d+(\.(\d{1,2}))?$/
 const INTEGER_REGEX = /^\d+$/
+const SIGNED_INTEGER_REGEX = /^-?\d+$/
+
+// Joi error type constants
+const ERROR_STRING_PATTERN_BASE = 'string.pattern.base'
+const ERROR_STRING_MAX = 'string.max'
+const ERROR_STRING_WHOLE_NUMBER_MAX = 'string.whole_number_max'
 
 /**
  * Validates a carbon decimal field value (up to 2 decimal places).
@@ -16,17 +22,17 @@ const INTEGER_REGEX = /^\d+$/
  */
 const validateCarbonDecimalString = (value, helpers) => {
   if (!DECIMAL_REGEX.test(value)) {
-    return helpers.error('string.pattern.base')
+    return helpers.error(ERROR_STRING_PATTERN_BASE)
   }
   const [intPart, decPart] = value.split('.')
   if (decPart === undefined) {
     // Whole number: max 18 digits
     if (intPart.length > MAX_WHOLE_NUMBER_DIGITS) {
-      return helpers.error('string.whole_number_max')
+      return helpers.error(ERROR_STRING_WHOLE_NUMBER_MAX)
     }
   } else if (intPart.length > MAX_EMISSION_DIGITS) {
     // Decimal: max 16 digits before decimal point
-    return helpers.error('string.max')
+    return helpers.error(ERROR_STRING_MAX)
   } else {
     // no error
   }
@@ -39,10 +45,27 @@ const validateCarbonDecimalString = (value, helpers) => {
  */
 const validateCarbonIntegerString = (value, helpers) => {
   if (!INTEGER_REGEX.test(value)) {
-    return helpers.error('string.pattern.base')
+    return helpers.error(ERROR_STRING_PATTERN_BASE)
   }
   if (value.length > MAX_COST_DIGITS) {
-    return helpers.error('string.max')
+    return helpers.error(ERROR_STRING_MAX)
+  }
+  return value
+}
+
+/**
+ * Validates a carbon signed integer field value (allows negative numbers).
+ * Used for £ fields that can be negative: net economic benefit.
+ * Max digits excludes the minus sign.
+ */
+const validateCarbonSignedIntegerString = (value, helpers) => {
+  if (!SIGNED_INTEGER_REGEX.test(value)) {
+    return helpers.error(ERROR_STRING_PATTERN_BASE)
+  }
+  // Count digits excluding minus sign
+  const digits = value.replace(/^-/, '')
+  if (digits.length > MAX_COST_DIGITS) {
+    return helpers.error(ERROR_STRING_MAX)
   }
   return value
 }
@@ -90,6 +113,24 @@ const createOptionalCarbonIntegerSchema = (label) =>
       'string.max': PROJECT_VALIDATION_MESSAGES.CARBON_COST_INVALID
     })
 
+const createOptionalCarbonSignedIntegerSchema = (label) =>
+  Joi.string()
+    .trim()
+    .allow(null, '')
+    .optional()
+    .custom((value, helpers) => {
+      if (value === null || value === undefined || value === '') {
+        return value
+      }
+      return validateCarbonSignedIntegerString(value, helpers)
+    })
+    .label(label)
+    .messages({
+      'string.base': PROJECT_VALIDATION_MESSAGES.CARBON_COST_INVALID,
+      'string.pattern.base': PROJECT_VALIDATION_MESSAGES.CARBON_COST_INVALID,
+      'string.max': PROJECT_VALIDATION_MESSAGES.CARBON_COST_INVALID
+    })
+
 const createRequiredCarbonOperationalCostForecastSchema = (label) =>
   Joi.string()
     .trim()
@@ -117,7 +158,7 @@ export const carbonCostAvoidedOptionalSchema =
 
 // £ integer fields
 export const carbonSavingsNetEconomicBenefitOptionalSchema =
-  createOptionalCarbonIntegerSchema('carbonSavingsNetEconomicBenefit')
+  createOptionalCarbonSignedIntegerSchema('carbonSavingsNetEconomicBenefit')
 export const carbonOperationalCostForecastRequiredSchema =
   createRequiredCarbonOperationalCostForecastSchema(
     'carbonOperationalCostForecast'

src/common/schemas/project/carbon.test.js

@@ -142,6 +142,36 @@ describe('Carbon Impact Schemas', () => {
       expect(error).toBeUndefined()
       expect(value).toBe('500')
     })
+
+    it('should accept negative integers', () => {
+      const { error, value } =
+        carbonSavingsNetEconomicBenefitOptionalSchema.validate('-150000')
+      expect(error).toBeUndefined()
+      expect(value).toBe('-150000')
+    })
+
+    it('should accept negative single digit', () => {
+      const { error, value } =
+        carbonSavingsNetEconomicBenefitOptionalSchema.validate('-5')
+      expect(error).toBeUndefined()
+      expect(value).toBe('-5')
+    })
+
+    it('should reject negative values exceeding max digits (excluding minus)', () => {
+      const oversized = '-1234567890123456789' // 19 digits
+      const { error } =
+        carbonSavingsNetEconomicBenefitOptionalSchema.validate(oversized)
+      expect(error).toBeDefined()
+      expect(error.details[0].message).toBe('CARBON_COST_INVALID')
+    })
+
+    it('should accept negative values at max digits boundary', () => {
+      const maxDigits = '-123456789012345678' // 18 digits
+      const { error, value } =
+        carbonSavingsNetEconomicBenefitOptionalSchema.validate(maxDigits)
+      expect(error).toBeUndefined()
+      expect(value).toBe(maxDigits)
+    })
   })
 
   describe('carbonOperationalCostForecastRequiredSchema', () => {