Screen blank array and hash params

lib/has_scope.rb

@@ -115,6 +115,7 @@ def apply_scopes(target, hash=params)
       end
 
       value = parse_value(options[:type], key, value)
+      value = normalize_blanks(options[:type], value) if value
 
       if call_scope && (value.present? || options[:allow_blank])
         current_scopes[key] = value
@@ -134,14 +135,25 @@ def parse_value(type, key, value) #:nodoc:
     end
   end
 
+  # Screens pseudo-blank params.
+  def normalize_blanks(type, value) #:nodoc:
+    if type == :array
+      value.select { |v| v.present? }
+    elsif type == :hash
+      value.select { |k, v| v.present? }
+    else
+      value
+    end
+  end
+
   # Call the scope taking into account its type.
   def call_scope_by_type(type, scope, target, value, options) #:nodoc:
     block = options[:block]
 
     if type == :boolean
       block ? block.call(self, target) : target.send(scope)
     elsif value && options.key?(:using)
-      value = value.values_at(*options[:using])
+      value = value.values_at(*options[:using].map(&:to_s))
       block ? block.call(self, target, value) : target.send(scope, *value)
     else
       block ? block.call(self, target, value) : target.send(scope, value)

test/has_scope_test.rb

@@ -161,6 +161,15 @@ def test_scope_of_type_hash_with_using
     assert_equal({ :args_paginate => hash }, current_scopes)
   end
 
+  def test_hash_with_blank_values_is_ignored
+    hash = { "page" => "", "per_page" => "" }
+    Tree.expects(:paginate).never
+    Tree.expects(:all).returns([mock_tree])
+    get :index, :paginate => hash
+    assert_equal([mock_tree], assigns(:trees))
+    assert_equal({ }, current_scopes)
+  end
+
   def test_scope_of_type_array
     array = %w(book kitchen sport)
     Tree.expects(:categories).with(array).returns(Tree)
@@ -170,6 +179,14 @@ def test_scope_of_type_array
     assert_equal({ :categories => array }, current_scopes)
   end
 
+  def test_array_of_blank_values_is_ignored
+    Tree.expects(:categories).never
+    Tree.expects(:all).returns([mock_tree])
+    get :index, :categories => [""]
+    assert_equal([mock_tree], assigns(:trees))
+    assert_equal({ }, current_scopes)
+  end
+
   def test_scope_of_invalid_type_silently_fails
     Tree.expects(:all).returns([mock_tree])
     get :index, :paginate => "1"