Surrounded requirements regex by parenthesis

[b-viguier]

Currently, the regex used for requirements is automatically surrounded by characters ^ and $ (see ParamFetcher.php code). It seems legit and very helpful, since wen can easily write A+ to match at least one A, or even A if we expect only one occurence.

Unfortunately, this helper may introduce a misunderstanding of what really happens in the case where we want to match an A or a B character. Our first guess will be A|B, but is is wrong. This requirement will produce the regex ^A|B$, matching all strings starting by A or finishing by B.

This behavior is absolutely normal, this is not a bug, but IMHO it is counter-intuitive (then, dangerous). In the previous example, I should use parenthesis to reach my goal: ^(A|B)$. So here my proposal, to add by default these surrounding parenthesis, in order to make requirement string A|B to match exactly one A, or exactly one B.

According to my tests, even if you already used some ^ or $ in your regex, this should be retro-compatible. Nevertheless, this is a breaking change as soon as you were really expecting the string A|B to match Abc (or );TRUNCATE Users;#B 😉 )

I updated corresponding tests in this PR, I am looking forward for your feedback, and thanks for all the work done for this library 👍

[stof]

please use a non-capturing group (adding a new capturing group makes it slower for all cases, and can break cases using advanced regex features)

[b-viguier]

👍

[stof]

please add a test using a regex A|B to ensure it indeed rejects Ac

[b-viguier]

@stof Done
I tried to mock the validator in order to cover 99% of the use cases, but since this service is injected we cannot guarantee that a standard Symfony RegexValidatorwill always be used.
I am still open to your remarks if you are not totally satisfied, thanks 😄

[b-viguier]

Nice!
😄