luhn_checksum

Implementation of the Luhn algorithm for detecting credit card numbers in a stream of input text.

Example:

LuhnChecksum.valid?('123451234512348')

• LuhnChecksum.valid? currently assumes that input text has already been validated to consist of only digits. An exception will be thrown if non-digits are passed in.
• LuhnChecksum.valid? does not validate that the number passed in is any particular length. The number 6789 will be considered valid, even though most credit card numbers are between 13 and 19 digits in length.

Apache License 2.0