keep filter conditions from being deleted

This a backport of 4dd5b10 from master to 0-6-stable

Ref: #2523, #2832

lib/active_admin/filters/forms.rb

@@ -66,12 +66,10 @@ def active_admin_filters_form_for(search, filters, options = {})
         form_for search, options do |f|
           filters.group_by{ |o| o[:attribute] }.each do |attribute, array|
             opts     = array.last # grab last-defined `filter` call from DSL
-            should   = opts.delete(:if)     || proc{ true }
-            shouldnt = opts.delete(:unless) || proc{ false }
+            return if opts.key?(:if)     && !call_method_or_proc_on(self, opts[:if])
+            return if opts.key?(:unless) &&  call_method_or_proc_on(self, opts[:unless])
 
-            if call_method_or_proc_on(self, should) && !call_method_or_proc_on(self, shouldnt)
-              f.filter attribute, opts
-            end
+            f.filter attribute, opts.except(:if, :unless)
           end
 
           buttons = content_tag :div, :class => "buttons" do

lib/active_admin/filters/resource_extension.rb

@@ -13,8 +13,7 @@ def initialize(*)
       #
       # @return [Array] Filters that apply for this resource
       def filters
-        return [] unless filters_enabled?
-        filter_lookup
+        filters_enabled? ? filter_lookup : []
       end
 
       # Setter to enable / disable filters on this resource.

spec/unit/filters/filter_form_builder_spec.rb

@@ -308,34 +308,26 @@ def filter(name, options = {})
   end
 
   describe "conditional display" do
-
-    context "with :if block" do
-      let(:body) do
-        filter :body,   :if => proc{true}
-        filter :author, :if => proc{false}
-      end
-
-      it "should be displayed if true" do
-        body.should have_tag("input", :attributes => { :name => "q[body_contains]"})
-      end
-
-      it "should NOT be displayed if false" do
-        body.should_not have_tag("input", :attributes => { :name => "q[author_id_eq]"})
-      end
-    end
-
-    context "with :unless block" do
-      let(:body) do
-        filter :created_at, :unless => proc{false}
-        filter :updated_at, :unless => proc{true}
-      end
-
-      it "should be displayed if false" do
-        body.should have_tag("input", :attributes => { :name => "q[created_at_gte]"})
-      end
-
-      it "should NOT be displayed if true" do
-        body.should_not have_tag("input", :attributes => { :name => "q[updated_at_gte]"})
+    [:if, :unless].each do |verb|
+      should   = verb == :if ? "should"     : "shouldn't"
+      if_true  = verb == :if ? :should      : :should_not
+      if_false = verb == :if ? :should_not  : :should
+      context "with #{verb.inspect} proc" do
+        it "#{should} be displayed if true" do
+          body = filter :body, verb => proc{ true }
+          body.send if_true, have_tag("input", attributes: {name: "q[body_contains]"})
+        end
+        it "#{should} be displayed if false" do
+          body = filter :body, verb => proc{ false }
+          body.send if_false, have_tag("input", attributes: {name: "q[body_contains]"})
+        end
+        it "should still be hidden on the second render" do
+          filters = [attribute: :body, verb => proc{ verb == :unless }]
+          2.times do
+            body = render_filter scope, filters
+            body.should_not have_tag "input", attributes: {name: "q[body_contains]"}
+          end
+        end
       end
     end
   end