(maint) bump up code coverage

* add a comment on SLV-116 to fix tech-debt in `RototillerParam`
* add some tests around `#parent_name=`
* add some docs around `RototillerParam`'s methods

lib/rototiller/task/params.rb

@@ -21,6 +21,13 @@ def message
         return ''
       end
 
+      # FIXME: (SLV-116) we shouldn't have env_var specific stuff in here
+      #   we don't use this in other params, but if we did it would break them
+      #   this breaks encapsulation a bit
+      # Record parent parameter's name so we can message appropriately
+      # @param [String] name parent's parameter instance name
+      # @api public
+      # @example param.parent_name = otherparam.name
       def parent_name=(name)
         name.each_char do |char|
           message = "You have defined an environment variable with an illegal character: #{char}"
@@ -29,6 +36,10 @@ def parent_name=(name)
         @parent_name = name
       end
 
+      # Record parent param's message so we can message appropriately
+      # @param [String] name parent parameter's message
+      # @api public
+      # @example param.parent_message = otherparam.message
       def parent_message=(message)
         @parent_message = message
       end

spec/rototiller/task/params_spec.rb

@@ -9,6 +9,20 @@ module Task
           expect(described_class.new.message).to eq('')
         end
       end
+      context '#parent_name=' do
+        let (:param) {described_class.new}
+        it 'sets @parent_name' do
+          param.parent_name = 'superkoolname'
+          expect(param.parent_name).to eq('superkoolname')
+        end
+        it 'protects against illegal env_vars' do
+          #raise ArgumentError.new(message) unless char =~ /[a-zA-Z]|\d|_/
+          # no hyphens
+          expect{ param.parent_name = '-' }.to raise_error(ArgumentError)
+          # no special chars
+          expect{ param.parent_name = '%' }.to raise_error(ArgumentError)
+        end
+      end
     end
 
   end