[Validator] Fix `CardSchemeValidator` double violation when value is non-numeric.
Making scheme option accept strings in addition to arrays.
better regexp, more test cases, added comments about each credit card
merged branch ricardclau/improve-creditcard-regexp (PR #6583)

This PR was merged into the master branch.

Commits
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5be0042 better regexp, more test cases, added comments about each credit card
cc278af [Validator] Fix `CardSchemeValidator` double violation when value is non-numeric. Making scheme option accept strings in addition to arrays.

Discussion
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[Validator] Improve regexp for Credit Cards and some more tests

Bug fix: yes
Feature addition: no
Backwards compatibility break: no
Symfony2 tests pass: yes
Fixes the following tickets:
Todo: Ensure these regexps are proper (credit card validation is always a pain)
License of the code: MIT
Documentation PR:

Regarding Cases excluded from new Regular Expressions:

- Credit card lengths should be respected, these regexp cover lengths in http://en.wikipedia.org/wiki/Bank_card_number
- Visa length can only be 16 and 13 (older ones)
- Diners Cards starting by 5 come from a joint venture between Diners Club and MasterCard, and should be processed like a MasterCard (according to http://www.regular-expressions.info/creditcard.html).
- There seems to be JCB cards starting by 2131 and 1800, I could find them is some places, also found these numbers being tested in Credit Card generators, but some people don't cover them. I don't know their story either

Any comments will be much appreciated!

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by fabpot at 2013-01-06T19:33:27Z

Thanks for working on this. It would be very valuable if you can add information about these regexes as comments (with links to relevant sources -- like what you've done in the PR description). Thanks.

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by ricardclau at 2013-01-06T21:01:52Z

Always glad to be able to contribute a little bit

@fabpot you mean @link / @see PHPDoc inside CardSchemeValidator.php? Or further comments in this discussion before adding them?

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by fabpot at 2013-01-06T21:16:48Z

The more information we can add in the class, the better it is.

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by ricardclau at 2013-01-07T20:56:05Z

I've added comments and included code from #6603 as I've said there. If you need something else, please let me know, once this is merged, #6603 can also be closed

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by fabpot at 2013-01-07T21:41:40Z

Can you keep the commit from #6603 to keep ownership?

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by ricardclau at 2013-01-07T21:44:16Z

I actually have thought about that... let me try my git skills :)

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by ricardclau at 2013-01-07T21:59:16Z

There you go!