[5.5] Force preg_grep to match entire value using start and end characters

[bencomeau]

Issue

When using the distinct:ignore_case flag during validation it will fail when evaluating integers; specifically, if the value being checked contains the integer under validation.

Example

Using 'foo.*' => 'distinct:ignore_case' with data such as 'foo' => ['1', '11'] will fail since 11 contains 1.

Similarily, using 'foo.*' => 'distinct:ignore_case' with data such as 'foo' => ['2', '425'] will fail since 425 contains 2.

Cause

The preg_grep() pattern does not contain the start (^) and end ($) characters which leads to the function returning partial matches.

Solution

Add the start (^) and end ($) characters to the preg_grep() pattern. Write additional tests including passing integers to the distinct:ignore_case validation flag.