Properly escape singular filters

0e2c4dd caused singular filters to avoid parsing the comma
into an array. However, it accidentally also prevented escaping special
characters. As a side effect, a `single: true` filter wrapped in `{{}}`
curlies would incorrectly see the value passed in containing `{{}}`.

This fixes things so singular filters still get parsed correctly, they
just avoid the comma/array scenario as originally intended.

Author: Lee Richmond

lib/graphiti/scoping/filter.rb

@@ -151,8 +151,6 @@ def parse_hash_value(filter, param_value, value, operator)
     # JSON of
     # {{{ "id": 1 }}} becomes { 'id' => 1 }
     def parse_string_value(filter, value)
-      return value if !!filter[:single]
-
       type = Graphiti::Types[filter[:type]]
       array_or_string = [:string, :array].include?(type[:canonical_name])
       if (arr = value.scan(/\[.*?\]/)).present? && array_or_string
@@ -165,20 +163,24 @@ def parse_string_value(filter, value)
         }
         value = value[0] if value.length == 1
       else
-        value = parse_string_arrays(value)
+        value = parse_string_arrays(value, !!filter[:single])
       end
       value
     end
 
-    def parse_string_arrays(value)
+    def parse_string_arrays(value, singular_filter)
       # Find the quoted strings
       quotes = value.scan(/{{.*?}}/)
       # remove them from the rest
       quotes.each { |q| value.gsub!(q, "") }
       # remove the quote characters from the quoted strings
       quotes.each { |q| q.gsub!("{{", "").gsub!("}}", "") }
       # merge everything back together into an array
-      value = Array(value.split(",")) + quotes
+      if singular_filter
+        value = Array(value) + quotes
+      else
+        value = Array(value.split(",")) + quotes
+      end
       # remove any blanks that are left
       value.reject! { |v| v.length.zero? }
       value = value[0] if value.length == 1

spec/filtering_spec.rb

@@ -200,6 +200,16 @@ def self.name
         expect(records.map(&:id)).to eq([employee2.id])
       end
     end
+
+    context 'and the filter is marked single: true' do
+      before do
+        resource.filter :first_name, :string, single: true
+      end
+
+      it 'works' do
+        expect(records.map(&:id)).to eq([employee2.id])
+      end
+    end
   end
 
   context "when passed null and filter marked allow_nil: true" do