Tip: RegExp implements case equality.

string_validation.rb

# If you want to check whether a string matches a regular expression,
# but not return the match data, you can just use === the case equality operator.

# Bad
!! ('foobar' =~ /bar/) #=> true
!! ('foo' =~ /bar/)    #=> false

# Good
/bar/ === 'foobar'     #=> true
/bar/ === 'foo'        #=> false

# This makes sense if you think about it in a case statement and === for RegExp.
case 'foobar'
when /foo/
  "makes sense"
end

# Implementing === on String to match RegExp is less sensical.
case /foo/
when 'foobar'
  "doesn't make sense"
end