Module: Philiprehberger::EmailValidator::Syntax

Defined in:
lib/philiprehberger/email_validator/syntax.rb

Overview

RFC 5322 compliant email syntax validation.

Validates local part rules, domain rules, and length limits according to the relevant RFCs (5321, 5322).

Constant Summary collapse

MAX_EMAIL_LENGTH =

Maximum total length of an email address (RFC 5321).

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MAX_LOCAL_LENGTH =

Maximum length of the local part (RFC 5321).

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MAX_DOMAIN_LENGTH =

Maximum length of the domain part (RFC 5321).

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MAX_LABEL_LENGTH =

Maximum length of a single domain label.

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LOCAL_CHAR_PATTERN =

Characters allowed in the local part without quoting (RFC 5322 dot-atom).

%r{\A[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+\z}
LABEL_PATTERN =

Pattern for a valid domain label.

/\A[a-zA-Z0-9](?:[a-zA-Z0-9-]*[a-zA-Z0-9])?\z/

Class Method Summary collapse

Class Method Details

.valid?(email) ⇒ Boolean

Check if an email address has valid syntax.

Parameters:

  • email (String) —

    the email address to check

Returns:

  • (Boolean) 


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# File 'lib/philiprehberger/email_validator/syntax.rb', line 64

def valid?(email)
  validate(email).empty?
end

.validate(email) ⇒ Array<String>

Validate the syntax of an email address.

Parameters:

  • email (String) —

    the email address to validate

Returns:

  • (Array<String>) —

    list of error messages (empty if valid)



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# File 'lib/philiprehberger/email_validator/syntax.rb', line 33

def validate(email)
  errors = []

  return ['email must be a string'] unless email.is_a?(String)

  stripped = email.strip

  return ['email must not be empty'] if stripped.empty?

  if stripped.length > MAX_EMAIL_LENGTH
    errors << "email exceeds maximum length of #{MAX_EMAIL_LENGTH} characters"
  end

  parts = stripped.split('@', -1)

  return ['email must contain an @ symbol'] if parts.length < 2

  return ['email must contain exactly one @ symbol'] if parts.length > 2

  local, domain = parts

  errors.concat(validate_local(local))
  errors.concat(validate_domain(domain))

  errors
end