Make a nicer error on regexp failure

[fnichol]

Yes, I had a brain fart where I forgot how to write a regexp... but maybe catch RegexpError and just print "Invalid regex" instead of some weird stacktrack like this:

borkbork ~/devel/gh/juliandunn/chef-client (master *)$ kitchen test *centos*
-----> Starting Kitchen (v1.0.0.rc.1)
/Users/juliandunn/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/test-kitchen-1.0.0.rc.1/lib/kitchen/cli.rb:311:in `get_filtered_instances': target of repeat operator is not specified: /*centos*/ (RegexpError)
    from /Users/juliandunn/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/test-kitchen-1.0.0.rc.1/lib/kitchen/cli.rb:297:in `parse_subcommand'
    from /Users/juliandunn/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/test-kitchen-1.0.0.rc.1/lib/kitchen/cli.rb:111:in `block in test'
    from /Users/juliandunn/.rbenv/versions/1.9.3-p448/lib/ruby/1.9.1/benchmark.rb:280:in `measure'
    from /Users/juliandunn/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/test-kitchen-1.0.0.rc.1/lib/kitchen/cli.rb:107:in `test'
    from /Users/juliandunn/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/thor-0.18.1/lib/thor/command.rb:27:in `run'
    from /Users/juliandunn/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/thor-0.18.1/lib/thor/invocation.rb:120:in `invoke_command'
    from /Users/juliandunn/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/test-kitchen-1.0.0.rc.1/lib/kitchen/cli.rb:258:in `invoke_task'
    from /Users/juliandunn/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/thor-0.18.1/lib/thor.rb:363:in `dispatch'
    from /Users/juliandunn/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/thor-0.18.1/lib/thor/base.rb:439:in `start'
    from /Users/juliandunn/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/test-kitchen-1.0.0.rc.1/bin/kitchen:13:in `block in <top (required)>'
    from /Users/juliandunn/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/test-kitchen-1.0.0.rc.1/lib/kitchen/errors.rb:81:in `with_friendly_errors'
    from /Users/juliandunn/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/test-kitchen-1.0.0.rc.1/bin/kitchen:13:in `<top (required)>'
    from /Users/juliandunn/.rbenv/versions/1.9.3-p448/bin/kitchen:19:in `load'
    from /Users/juliandunn/.rbenv/versions/1.9.3-p448/bin/kitchen:19:in `<main>'
    from /Users/juliandunn/.rbenv/versions/1.9.3-p448/bin/ruby_noexec_wrapper:14:in `eval'
    from /Users/juliandunn/.rbenv/versions/1.9.3-p448/bin/ruby_noexec_wrapper:14:in `<main>'

[fnichol]

Noted and good UI idea. On it…

[fnichol]

This should do the trick and contains (gasp) a test! The Kitchen CLI uses the same Regexp globbing logic for all subcommands so testing the kitchen list subcommand should be all right for the moment. Lots of feature backfilling in the near future.