feat: make bootstrapping more ruby idiomatic

README.md

@@ -79,7 +79,7 @@ Argument | Description | Required? |  Type |  Default Value|
 `backup_file` | Filename to store the last known state from the Unleash server. Best to not change this from the default. | N | String | `Dir.tmpdir + "/unleash-#{app_name}-repo.json` |
 `logger` | Specify a custom `Logger` class to handle logs for the Unleash client. | N | Class | `Logger.new(STDOUT)` |
 `log_level` | Change the log level for the `Logger` class. Constant from `Logger::Severity`. | N | Constant | `Logger::WARN` |
-`bootstrapper` | Defines a bootstrapper object that unleash will use to get a list of toggles on load before it reads them from the unleash server. This is useful for loading large states on startup without hitting the network. Bootstrapping classes are provided for URL and file reading but you can implement your own for other sources of toggles. | N | Class | `nil` |
+`bootstrapper` | Bootstrapper object to get a list of toggles on load before it reads them from the unleash server. This is useful for loading large states on startup without hitting the network. Bootstrapping classes are provided for URL and file reading but you can implement your own for other sources of toggles. | N | Unleash::Bootstrap::Base or Nil | `nil` |
 
 For in a more in depth look, please see `lib/unleash/configuration.rb`.
 
@@ -95,7 +95,7 @@ require 'unleash/bootstrap'
             app_name: 'my_ruby_app',
             url: 'http://unleash.herokuapp.com/api',
             custom_http_headers: { 'Authorization': '<API token>' },
-            bootstrapper: Unleash::FileBootStrapper.new('./default-toggles.json')
+            bootstrapper: Unleash::Bootstrap::FromFile.new('./default-toggles.json')
           )
 
 feature_name = "AwesomeFeature"
@@ -124,7 +124,6 @@ Unleash.configure do |config|
   # config.instance_id = "#{Socket.gethostname}"
   config.logger   = Rails.logger
   config.environment = Rails.env
-  config.bootstrapper = Unleash::FileBootStrapper.new('./default-toggles.json')
 end
 
 UNLEASH = Unleash::Client.new
@@ -315,6 +314,12 @@ This client comes with the all the required strategies out of the box:
  * UnknownStrategy
  * UserWithIdStrategy
 
+## Available Bootstrap Classes
+
+This client comes with these classes to load unleash features on startup, before making a request to the Unleash API:
+
+ * Unleash::Bootstrap::FromFile
+ * Unleash::Bootstrap::FromUri
 
 ## Development
 

examples/bootstrap.rb

@@ -2,7 +2,7 @@
 
 require 'unleash'
 require 'unleash/context'
-require 'unleash/bootstrap'
+require 'unleash/bootstrap/from_file'
 
 puts ">> START bootstrap.rb"
 
@@ -14,10 +14,9 @@
   refresh_interval: 2,
   metrics_interval: 2,
   retry_limit: 2,
-  bootstrapper: Unleash::FileBootStrapper.new('./examples/default-toggles.json')
+  bootstrapper: Unleash::Bootstrap::FromFile.new('./examples/default-toggles.json')
 )
 
-# feature_name = "AwesomeFeature"
 feature_name = "featureX"
 unleash_context = Unleash::Context.new
 unleash_context.user_id = 123

lib/unleash/bootstrap/base.rb

@@ -0,0 +1,18 @@
+module Unleash
+  module Bootstrap
+    class NotImplemented < RuntimeError
+    end
+
+    class Base
+      def read
+        raise NotImplemented, "Bootstrap is not implemented"
+      end
+
+      def extract_features(bootstrap_hash)
+        raise NotImplemented, "The provided bootstrap data doesn't seem to have a valid set of toggles" if bootstrap_hash['version'] < 1
+
+        bootstrap_hash['features']
+      end
+    end
+  end
+end

lib/unleash/bootstrap/from_file.rb

@@ -0,0 +1,18 @@
+module Unleash
+  module Bootstrap
+    class FromFile < Base
+      attr_accessor :file_path
+
+      # @param file_path [String]
+      def initialize(file_path)
+        self.file_path = file_path
+      end
+
+      def read
+        file_content = File.read(self.file_path)
+        bootstrap_hash = JSON.parse(file_content)
+        extract_features(bootstrap_hash)
+      end
+    end
+  end
+end

lib/unleash/bootstrap/from_uri.rb

@@ -0,0 +1,20 @@
+module Unleash
+  module Bootstrap
+    class FromUri < Base
+      attr_accessor :uri, :headers
+
+      # @param uri [String]
+      # @param headers [Hash, nil] HTTP headers to use. If not set, the unleash client SDK ones will be used.
+      def initialize(uri, headers = nil)
+        self.uri = URI(uri)
+        self.headers = headers
+      end
+
+      def read
+        response = Unleash::Util::Http.get(self.uri, nil, self.headers)
+        bootstrap_hash = JSON.parse(response.body)
+        extract_features(bootstrap_hash)
+      end
+    end
+  end
+end

lib/unleash/toggle_fetcher.rb

@@ -16,11 +16,12 @@ def initialize
 
       # start by fetching synchronously, and failing back to reading the backup file.
       begin
-        if !self.bootstrapper.nil? # if the consumer provides a bootstrapper, we're going to assume they want to use it
+        if self.bootstrapper.nil?
+          fetch
+        else
+          # if the consumer provides a bootstrapper, use it!
           synchronize_with_local_cache! self.bootstrapper.read
           update_running_client!
-        else
-          fetch
         end
       rescue StandardError => e
         Unleash.logger.warn "ToggleFetcher was unable to fetch from the network or bootstrap, attempting to read from backup file."

lib/unleash/util/http.rb

@@ -4,10 +4,10 @@
 module Unleash
   module Util
     module Http
-      def self.get(uri, etag = nil)
+      def self.get(uri, etag = nil, headers_override = nil)
         http = http_connection(uri)
 
-        request = Net::HTTP::Get.new(uri.request_uri, http_headers(etag))
+        request = Net::HTTP::Get.new(uri.request_uri, http_headers(etag, headers_override))
 
         http.request(request)
       end
@@ -30,10 +30,13 @@ def self.http_connection(uri)
         http
       end
 
-      def self.http_headers(etag = nil)
+      # @param etag [String, nil]
+      # @param headers_override [Hash, nil]
+      def self.http_headers(etag = nil, headers_override = nil)
         Unleash.logger.debug "ETag: #{etag}" unless etag.nil?
 
         headers = (Unleash.configuration.http_headers || {}).dup
+        headers = headers_override if headers_override.is_a?(Hash)
         headers['Content-Type'] = 'application/json'
         headers['If-None-Match'] = etag unless etag.nil?
 

spec/unleash/bootstrap/from_file_spec.rb

@@ -0,0 +1,22 @@
+require 'spec_helper'
+require 'rspec/json_expectations'
+require 'unleash/bootstrap/base'
+require 'unleash/bootstrap/from_file'
+require 'json'
+
+RSpec.describe Unleash::Bootstrap::FromFile do
+  before do
+    Unleash.configuration = Unleash::Configuration.new
+    Unleash.logger = Unleash.configuration.logger
+  end
+
+  it 'loads bootstrap toggle correctly from file' do
+    bootstrap_file = './spec/unleash/bootstrap-resources/features-v1.json'
+
+    bootstrapper = Unleash::Bootstrap::FromFile.new(bootstrap_file)
+    file_contents = File.open(bootstrap_file).read
+    file_features = JSON.parse(file_contents)['features']
+
+    expect(bootstrapper.read).to include_json(file_features)
+  end
+end

spec/unleash/bootstrap/from_uri_spec.rb

@@ -0,0 +1,26 @@
+require 'unleash/bootstrap/from_uri'
+require 'json'
+
+RSpec.describe Unleash::Bootstrap::FromUri do
+  it 'loads bootstrap toggle correctly from URL' do
+    bootstrap_file = './spec/unleash/bootstrap-resources/features-v1.json'
+
+    file_contents = File.open(bootstrap_file).read
+    file_features = JSON.parse(file_contents)['features']
+
+    WebMock.stub_request(:get, "http://test-url/bootstrap-goodness")
+      .with(
+        headers: {
+          'Accept' => '*/*',
+          'Accept-Encoding' => 'gzip;q=1.0,deflate;q=0.6,identity;q=0.3',
+          'Content-Type' => 'application/json',
+          'User-Agent' => 'Ruby'
+        }
+      )
+      .to_return(status: 200, body: file_contents, headers: {})
+
+    bootstrapper = Unleash::Bootstrap::FromUri.new('http://test-url/bootstrap-goodness', {})
+
+    expect(bootstrapper.read).to include_json(file_features)
+  end
+end