Gracefully handle empty string entityIDs (#33)

* Gracefully handle empty string entityIDs

* Bump version

* fix README

* Respond to Mike's CR feedback

Author: delikat

CHANGELOG

@@ -1,3 +1,8 @@
+-------------------------------------------------------------------------------
+1.1.1
+* Gracefully handle empty traffic allocation ranges.
+-------------------------------------------------------------------------------
+
 -------------------------------------------------------------------------------
 1.1.0
 * Introduce support for event tags.

README.md

@@ -1,42 +1,42 @@
-#Optimizely Ruby SDK
+# Optimizely Ruby SDK
 [![Build Status](https://travis-ci.org/optimizely/ruby-sdk.svg?branch=master)](https://travis-ci.org/optimizely/ruby-sdk)
 [![Coverage Status](https://coveralls.io/repos/github/optimizely/ruby-sdk/badge.svg)](https://coveralls.io/github/optimizely/ruby-sdk)
 [![Apache 2.0](https://img.shields.io/github/license/nebula-plugins/gradle-extra-configurations-plugin.svg)](http://www.apache.org/licenses/LICENSE-2.0)
 
 This repository houses the Ruby SDK for Optimizely's Full Stack product.
 
-##Getting Started
+## Getting Started
 
-###Installing the SDK
+### Installing the SDK
 
 The SDK is available through [RubyGems](https://rubygems.org/gems/optimizely-sdk). To install:
 
 ```
 gem install optimizely-sdk
 ```
 
-###Using the SDK
+### Using the SDK
 See the Optimizely Full Stack [developer documentation](http://developers.optimizely.com/server/reference/index.html) to learn how to set up your first Full Stack project and use the SDK.
 
-##Development
+## Development
 
-###Building the SDK
+### Building the SDK
 
 To build a local copy of the gem which will be output to `/pkg`:
 
 ```
 rake build
 ```
 
-###Unit tests
+### Unit tests
 
-#####Running all tests
+##### Running all tests
 You can run all unit tests with:
 
 ```
 rake spec
 ```
 
-###Contributing
+### Contributing
 
 Please see [CONTRIBUTING](CONTRIBUTING.md).

lib/optimizely/bucketer.rb

@@ -100,7 +100,7 @@ def bucket(experiment_key, user_id)
       @config.logger.log(Logger::DEBUG, "Assigned variation bucket #{bucket_value} to user '#{user_id}'.")
       traffic_allocations = @config.get_traffic_allocation(experiment_key)
       variation_id = find_bucket(bucket_value, traffic_allocations)
-      if variation_id
+      if variation_id && variation_id != ''
         variation_key = @config.get_variation_key_from_id(experiment_key, variation_id)
         @config.logger.log(
           Logger::INFO,
@@ -109,6 +109,11 @@ def bucket(experiment_key, user_id)
         return variation_id
       end
 
+      # Handle the case when the traffic range is empty due to sticky bucketing
+      if variation_id == ''
+        @config.logger.log(Logger::DEBUG, 'Bucketed into an empty traffic range. Returning nil.')
+      end
+
       @config.logger.log(Logger::INFO, "User '#{user_id}' is in no variation.")
       nil
     end

lib/optimizely/version.rb

@@ -14,5 +14,5 @@
 #    limitations under the License.
 #
 module Optimizely
-  VERSION = '1.1.0'.freeze
+  VERSION = '1.1.1'.freeze
 end

spec/bucketing_spec.rb

@@ -133,6 +133,15 @@ def get_bucketing_id(user_id, entity_id=nil)
     bucketer.bucket('group1_exp1', 'test_user')
   end
 
+  it 'should return nil when user is in an empty traffic allocation range due to sticky bucketing' do
+    expect(bucketer).to receive(:find_bucket).once.and_return('')
+    expect(bucketer.bucket('test_experiment', 'test_user')).to be_nil
+    expect(spy_logger).to have_received(:log)
+                      .with(Logger::INFO, "User 'test_user' is in no variation.")
+    expect(spy_logger).to have_received(:log)
+                      .with(Logger::DEBUG, "Bucketed into an empty traffic range. Returning nil.")
+  end
+
   describe 'logging' do
     it 'should log the results of bucketing a user into variation 1' do
       expect(bucketer).to receive(:generate_bucket_value).and_return(50)