Filter tests by regular expression

[Matthias Simon]

Description

Test tags are a fundamental mechanism to group tests. Convenience functions for selecting tests based on tags would significantly improve user experience.

Proposal

Add filter options to k3 list:

• -r <regex>, --tests-regex <regex>: List tests matching regular expression.
• -R <regex>, --tags-regex <regex>: List tests with tags matching regular expression
• -x <regex>, --tests-regex <regex>: Exclude tests matching regular expresion.
• -X <regex>, --tags-exclude <regex>: Exclude tests with labels matching regular expression

<regex> for tags is used to specify case insensitive, colon separated regular expressions for trimmed tag name and tag value. Example:

    $ k3 list --tags-regex '@author: John.*' --tags-exclude '@WIP'

Please note above regex would match following tags:

    // @author: John Doe
    // @author  John Doe
    // @AUTHOR: John Doe