feat: Support transient identities and traits

- Add optional `transient` argument to `get_identity_flags`
- Add support for trait configuration values with optional `transient` key
- Remove unneeded default argument values from private methods
- Remove unneeded comments from the spec

Author: khvn26

lib/flagsmith.rb

@@ -148,11 +148,13 @@ def get_environment_flags # rubocop:disable Naming/AccessorMethodName
     # environment, e.g. email address, username, uuid
     # traits { key => value } is a dictionary of traits to add / update on the identity in
     # Flagsmith, e.g. { "num_orders": 10 }
+    # in lieu of a trait value, a trait coniguration dictionary can be provided,
+    # e.g. { "num_orders": { "value": 10, "transient": true } }
     # returns Flags object holding all the flags for the given identity.
-    def get_identity_flags(identifier, **traits)
+    def get_identity_flags(identifier, transient = false, **traits) # rubocop:disable Style/OptionalBooleanParameter
       return get_identity_flags_from_document(identifier, traits) if environment
 
-      get_identity_flags_from_api(identifier, traits)
+      get_identity_flags_from_api(identifier, traits, transient)
     end
 
     def feature_enabled?(feature_name, default: false)
@@ -253,16 +255,16 @@ def process_environment_flags_from_api
     end
 
     # rubocop:disable Metrics/MethodLength
-    def get_identity_flags_from_api(identifier, traits = {})
+    def get_identity_flags_from_api(identifier, traits, transient)
       if offline_handler
         begin
-          process_identity_flags_from_api(identifier, traits)
+          process_identity_flags_from_api(identifier, traits, transient)
         rescue StandardError
           get_identity_flags_from_document(identifier, traits)
         end
       else
         begin
-          process_identity_flags_from_api(identifier, traits)
+          process_identity_flags_from_api(identifier, traits, transient)
         rescue StandardError
           if default_flag_handler
             return Flagsmith::Flags::Collection.new(
@@ -276,8 +278,8 @@ def get_identity_flags_from_api(identifier, traits = {})
     end
     # rubocop:enable Metrics/MethodLength
 
-    def process_identity_flags_from_api(identifier, traits = {})
-      data = generate_identities_data(identifier, traits)
+    def process_identity_flags_from_api(identifier, traits, transient)
+      data = generate_identities_data(identifier, traits, transient)
       json_response = api_client.post(@config.identities_url, data.to_json).body
 
       Flagsmith::Flags::Collection.from_api(
@@ -311,10 +313,13 @@ def get_identity_model(identifier, traits = {})
     end
     # rubocop:enable Metrics/MethodLength
 
-    def generate_identities_data(identifier, traits = {})
+    def generate_identities_data(identifier, traits, transient)
       {
         identifier: identifier,
-        traits: traits.map { |key, value| { trait_key: key, trait_value: value } }
+        transient: transient,
+        traits: traits.map do |key, value|
+          value.is_a?(Hash) ? { trait_key: key, trait_value: value[:value], transient: value[:transient] || false } : { trait_key: key, trait_value: value }
+        end
       }
     end
   end

spec/sdk/fixtures/identities.json

@@ -59,12 +59,14 @@
     {
       "id": 215352,
       "trait_key": "roles",
-      "trait_value": "[\"admin\",\"staff\"]"
+      "trait_value": "[\"admin\",\"staff\"]",
+      "transient": false
     },
     {
       "id": 215988,
       "trait_key": "foo",
-      "trait_value": "bar"
+      "trait_value": "bar",
+      "transient": false
     }
   ]
-}
+}

spec/sdk/flagsmith_spec.rb

@@ -62,39 +62,6 @@
     end
   end
 
-  # describe '#set_trait' do
-  #   let(:trait_key) { 'foo' }
-  #   let(:trait_value) { 'bar' }
-  #   let(:post_body) do
-  #     {
-  #       identity: { identifier: user_id },
-  #       trait_key: Flagsmith::Flags::Collection.normalize_key(trait_key),
-  #       trait_value: trait_value
-  #     }.to_json
-  #   end
-  #
-  #   it 'sets a trait for a given user' do
-  #     trait_response = OpenStruct.new(body: {})
-  #     expect(mock_api_client).to receive(:post).with('traits/', post_body).and_return(trait_response)
-  #     subject.set_trait user_id, trait_key, trait_value
-  #   end
-  #
-  #   it 'errors if user_id.nil?' do
-  #     expect { subject.set_trait nil, trait_key, trait_value }.to raise_error(StandardError)
-  #   end
-  # end
-
-  # describe '#get_traits' do
-  #   it 'returns hash of traits for a given user' do
-  #     traits = subject.get_traits(user_id)
-  #     expect(traits['roles']).to eq(%w[admin staff].to_json)
-  #     expect(traits.length).to eq(2)
-  #   end
-  #   it 'returns {} for user_id.nil?' do
-  #     expect(subject.get_traits(nil)).to eq({})
-  #   end
-  # end
-
   describe '#normalize_key' do
     it 'returns an empty string given nil' do
       expect(Flagsmith::Flags::Collection.normalize_key(nil)).to eq('')
@@ -122,4 +89,41 @@
       expect(subject.get_identity_segments("identifier", {"age": 39}).length).to eq(1)
     end
   end
+
+  describe '#get_identity_flags' do
+    context 'with transient identity' do
+      before {
+        transient_identities_response = OpenStruct.new(body: { **identities_response.body } )
+        transient_identities_response.body[:traits] = identities_response.body[:traits].map{ |api_trait| { **api_trait, transient: true } }
+        allow(mock_api_client).to receive(:post).with(
+          'identities/', { identifier: user_id, transient: true, traits: [] }.to_json
+        ).and_return(transient_identities_response)    
+      }
+
+      it 'sends expected request' do
+        flags = subject.get_identity_flags(user_id, true)
+        expect(flags.feature_enabled?(:feature_one)).to eq(false)
+        expect(flags.feature_enabled?('feature_two')).to eq(true)
+        expect(flags.feature_enabled?(:feature_three)).to eq(true)
+      end
+    end
+
+    context 'with transient trait' do 
+      before {
+        transient_trait_data = { trait_key: "age", trait_value: 42, transient: true }
+        transient_traits_response = OpenStruct.new(body: { **identities_response.body } )
+        transient_traits_response.body[:traits] = transient_traits_response.body[:traits] + [transient_trait_data]
+        allow(mock_api_client).to receive(:post).with(
+          'identities/', { identifier: user_id, transient: false, traits: [transient_trait_data] }.to_json
+        ).and_return(transient_traits_response)    
+      }
+
+      it 'sends expected request' do
+        flags = subject.get_identity_flags(user_id, age: { value: 42, transient: true })
+        expect(flags.feature_enabled?(:feature_one)).to eq(false)
+        expect(flags.feature_enabled?('feature_two')).to eq(true)
+        expect(flags.feature_enabled?(:feature_three)).to eq(true)
+      end
+    end
+  end
 end

spec/sdk/shared_mocks.rb

@@ -30,7 +30,7 @@
                                            .and_return(mock_api_client)
     allow(mock_api_client).to receive(:get).with('flags/').and_return(flags_response)
     allow(mock_api_client).to receive(:post).with(
-      'identities/', { identifier: user_id, traits: [] }.to_json
+      'identities/', { identifier: user_id, transient: false, traits: [] }.to_json
     ).and_return(identities_response)
     allow(mock_api_client).to receive(:get).with('environment-document/')
                                            .and_return(environment_document_response)