Allow feature flag names to be a symbol

lib/feature.rb

@@ -39,7 +39,7 @@ def persisted?(feature)
       # Flipper creates on-memory features when asked for a not-yet-created one.
       # If we want to check if a feature has been actually set, we look for it
       # on the persisted features list.
-      persisted_names.include?(feature.name)
+      persisted_names.include?(feature.name.to_s)
     end
 
     def enabled?(key, thing = nil)

spec/lib/feature_spec.rb

@@ -39,18 +39,36 @@
   end
 
   describe '.persisted?' do
-    it 'returns true for a persisted feature' do
-      Feature::FlipperFeature.create!(key: 'foo')
+    context 'when the feature is persisted' do
+      it 'returns true when feature name is a string' do
+        Feature::FlipperFeature.create!(key: 'foo')
+
+        feature = double(:feature, name: 'foo')
+
+        expect(described_class.persisted?(feature)).to eq(true)
+      end
+
+      it 'returns true when feature name is a symbol' do
+        Feature::FlipperFeature.create!(key: 'foo')
 
-      feature = double(:feature, name: 'foo')
+        feature = double(:feature, name: :foo)
 
-      expect(described_class.persisted?(feature)).to eq(true)
+        expect(described_class.persisted?(feature)).to eq(true)
+      end
     end
 
-    it 'returns false for a feature that is not persisted' do
-      feature = double(:feature, name: 'foo')
+    context 'when the feature is not persisted' do
+      it 'returns false when feature name is a string' do
+        feature = double(:feature, name: 'foo')
+
+        expect(described_class.persisted?(feature)).to eq(false)
+      end
 
-      expect(described_class.persisted?(feature)).to eq(false)
+      it 'returns false when feature name is a symbol' do
+        feature = double(:feature, name: :bar)
+
+        expect(described_class.persisted?(feature)).to eq(false)
+      end
     end
   end