FilterParamMatcher supports Regexps

NEWS.md

@@ -12,6 +12,9 @@
   session variable in question was set to nil (previously this actually did
   nothing).
 
+* Fix `filter_param` so that it works when `config.filter_parameters` contains
+  regexes.
+
 ### Improvements
 
 * `have_and_belongs_to_many` now checks to make sure that the join table

lib/shoulda/matchers/action_controller/filter_param_matcher.rb

@@ -28,7 +28,7 @@ module Shoulda
       # @private
       class FilterParamMatcher
         def initialize(key)
-          @key = key.to_s
+          @key = key
         end
 
         def matches?(controller)
@@ -52,11 +52,18 @@ module Shoulda
         private
 
         def filters_key?
-          filtered_keys.include?(@key)
+          filtered_keys.any? do |filter|
+            case filter
+            when Regexp
+              filter =~ @key
+            else
+              filter == @key
+            end
+          end
         end
 
         def filtered_keys
-          Rails.application.config.filter_parameters.map(&:to_s)
+          Rails.application.config.filter_parameters
         end
       end
     end

spec/shoulda/matchers/action_controller/filter_param_matcher_spec.rb

@@ -7,6 +7,12 @@ describe Shoulda::Matchers::ActionController::FilterParamMatcher do
     expect(nil).to filter_param(:secret)
   end
 
+  it 'accepts filtering a parameter matching a filtered regex' do
+    filter(/(?!tip)pin(?!g)/)
+
+    expect(nil).to filter_param(:pin)
+  end
+
   it 'rejects filtering an unfiltered parameter' do
     filter(:secret)
     matcher = filter_param(:other)