Magento 2 Store Code validation regex: doesn't support uppercase letters in store code

[zack6849]

Preconditions

1. Magento v2.1.9 (Probably earlier versions as well)

Steps to reproduce

1. Go to stores > all stores
2. Create Store View
3. Attempt to create a store code with uppercase letters

Expected result

1. It should work, or give an error message

Actual result

1. You get an error message back saying

The store code may contain only letters (a-z), numbers (0-9) or underscore (_), and the first character must be a letter.

Now, this error message is totally acceptable, makes perfect sense, but it let's say, for example, your store code you tried was ACME_STORE1, it's only letters and numbers, and has an underscore, and the first character is a letter, by all accounts, this should work, as far as i'm aware.

Unless there's a reason the store code is lowercase only the regex here:

magento2/app/code/Magento/Store/Model/Store.php

Line 466 in fd715d7

$storeCodeRule = new \Zend_Validate_Regex('/^[a-z]+[a-z0-9_]*$/');

should either be changed to /^[A-z]+[A-z0-9_]*$/, or the message should be changed to indicate that only lowercase letters are supported.

[magento-engcom-team]

@zack6849, thank you for your report.
We've created internal ticket(s) MAGETWO-83245 to track progress on the issue.

[manuelson]

I am working on it at #mm17es