Merge pull request #371 from jnunemaker/exist

Add exist to feature, dsl and flipper default instance delegation

lib/flipper.rb

@@ -64,7 +64,7 @@ def instance=(flipper)
                  :enable_percentage_of_time, :disable_percentage_of_time,
                  :time, :percentage_of_time,
                  :features, :feature, :[], :preload, :preload_all,
-                 :adapter, :add, :remove, :import,
+                 :adapter, :add, :exist?, :remove, :import,
                  :memoize=, :memoizing?
 
   # Public: Use this to register a group by name.

lib/flipper/dsl.rb

@@ -151,6 +151,15 @@ def add(name)
       feature(name).add
     end
 
+    # Public: Has a feature been added in the adapter.
+    #
+    # name - The String or Symbol name of the feature.
+    #
+    # Returns true if added else false.
+    def exist?(name)
+      feature(name).exist?
+    end
+
     # Public: Remove a feature.
     #
     # name - The String or Symbol name of the feature.

lib/flipper/feature.rb

@@ -76,6 +76,13 @@ def add
       instrument(:add) { adapter.add(self) }
     end
 
+    # Public: Does this feature exist in the adapter.
+    #
+    # Returns true if exists in adapter else false.
+    def exist?
+      instrument(:exist?) { adapter.features.include?(key) }
+    end
+
     # Public: Removes this feature.
     #
     # Returns the result of Adapter#remove.

spec/flipper/dsl_spec.rb

@@ -312,6 +312,17 @@
     end
   end
 
+  describe '#exist?' do
+    it 'returns true if the feature is added in adapter' do
+      subject.add(:stats)
+      expect(subject.exist?(:stats)).to be(true)
+    end
+
+    it 'returns false if the feature is NOT added in adapter' do
+      expect(subject.exist?(:stats)).to be(false)
+    end
+  end
+
   describe '#remove' do
     it 'removes the feature' do
       subject.adapter.add(subject[:stats])

spec/flipper/feature_spec.rb

@@ -96,6 +96,17 @@
     end
   end
 
+  describe '#exist?' do
+    it 'returns true if feature is added in adapter' do
+      subject.add
+      expect(subject.exist?).to be(true)
+    end
+
+    it 'returns false if feature is NOT added in adapter' do
+      expect(subject.exist?).to be(false)
+    end
+  end
+
   describe '#remove' do
     it 'removes feature from adapter' do
       adapter.add(subject)
@@ -231,6 +242,17 @@
       expect(event.payload[:result]).not_to be_nil
     end
 
+    it 'is recorded for exist?' do
+      subject.exist?
+
+      event = instrumenter.events.last
+      expect(event).not_to be_nil
+      expect(event.name).to eq('feature_operation.flipper')
+      expect(event.payload[:feature_name]).to eq(:search)
+      expect(event.payload[:operation]).to eq(:exist?)
+      expect(event.payload[:result]).not_to be_nil
+    end
+
     it 'is recorded for remove' do
       subject.remove
 

spec/flipper_spec.rb

@@ -187,6 +187,10 @@
       expect(described_class.add(:search)).to eq(described_class.instance.add(:search))
     end
 
+    it 'delegates exist? to instance' do
+      expect(described_class.exist?(:search)).to eq(described_class.instance.exist?(:search))
+    end
+
     it 'delegates remove to instance' do
       expect(described_class.remove(:search)).to eq(described_class.instance.remove(:search))
     end