CEPValidator class

A validator that ensures a given string is a valid Brazilian postal code (CEP).

The CEPValidator checks whether the provided value follows the Brazilian CEP format, which consists of exactly 8 digits (without special characters) and is not a repeated sequence of numbers.

Validation Modes

• ValidationMode.formatted → Expects the CEP in the formatted pattern: "XXXXX-XXX" (e.g., "01001-000").
• ValidationMode.unformatted (default) → Expects only digits: "XXXXXXXX" (e.g., "01001000").

Example

final validator = CEPValidator(message: 'Invalid CEP');

print(validator.validate('01001-000'));  // null (valid)
print(validator.validate('01001000'));   // null (valid)
print(validator.validate('00000-000'));  // 'Invalid CEP' (invalid)
print(validator.validate('abcdefgh'));   // 'Invalid CEP' (invalid)
print(validator.validate('1234'));       // 'Invalid CEP' (invalid)
print(validator.validate(null));         // 'Invalid CEP' (invalid)

Behavior

• Ensures the CEP format matches the expected pattern.
• Removes non-digit characters when ValidationMode.unformatted is used.
• Rejects values where all characters are the same (e.g., "00000000" or "11111-111").