feat: improved logic, by simplifying.

- by instead of passing an object, we pass it as a string, we simplify the code by a lot.
- bootstrap reading classes are much simpler now
  (borderline we should ask ourselves if we still want to bundle them at all, since the responsibility would then just live outside of the SDK)
- allow setting bootstrap configuration, and also disabling the toggle fetcher at the same time. Useful when testing.
- use as simple test resources as possible. If we don't need it for testing, then we shouldn't bundle it.
  (as it makes it confusing for whoever comes afterwards)
- added tests from the Client class perspective too, so we know that all steps in between work as expected.

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` | 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` |
+`bootstrap_data` | Bootstrap data to be loaded on start-up. This is useful for loading large states on startup without (or before) hitting the network. | N | String | `nil` |
 
 For in a more in depth look, please see `lib/unleash/configuration.rb`.
 
@@ -89,14 +89,8 @@ For in a more in depth look, please see `lib/unleash/configuration.rb`.
 ```ruby
 require 'unleash'
 require 'unleash/context'
-require 'unleash/bootstrap'
 
-@unleash = Unleash::Client.new(
-            app_name: 'my_ruby_app',
-            url: 'http://unleash.herokuapp.com/api',
-            custom_http_headers: { 'Authorization': '<API token>' },
-            bootstrapper: Unleash::Bootstrap::FromFile.new('./default-toggles.json')
-          )
+@unleash = Unleash::Client.new(app_name: 'my_ruby_app', url: 'http://unleash.herokuapp.com/api', custom_http_headers: { 'Authorization': '<API token>' })
 
 feature_name = "AwesomeFeature"
 unleash_context = Unleash::Context.new
@@ -116,8 +110,6 @@ end
 Put in `config/initializers/unleash.rb`:
 
 ```ruby
-require 'unleash/bootstrap'
-
 Unleash.configure do |config|
   config.app_name = Rails.application.class.parent.to_s
   config.url      = 'http://unleash.herokuapp.com/api'
@@ -276,6 +268,27 @@ variant = UNLEASH.get_variant "ColorVariants", @unleash_context, fallback_varian
 puts "variant color is: #{variant.payload.fetch('color')}"
 ```
 
+#### Bootstrapping
+
+`bootstrap_data` configuration allows the client to be initialized with a predefined set of toggle states.
+The content of the parameter is a JSON string containing the response body from the unleash server.
+
+We provide two classes to help fetch the bootstrap files:
+* `Unleash::Bootstrap::FromFile`
+* `Unleash::Bootstrap::FromUri`
+
+Example usage:
+```ruby
+@unleash = Unleash::Client.new(
+        app_name: 'my_ruby_app',
+        url: 'http://unleash.herokuapp.com/api',
+        custom_http_headers: { 'Authorization': '<API token>' },
+        bootstrap_data: Unleash::Bootstrap::FromFile.new('./default-toggles.json').read
+        # or
+        # bootstrap_data: Unleash::Bootstrap::FromUri.new('https://example.com/unleash-default-toggles.json').read
+)
+
+```
 
 #### Client methods
 

examples/bootstrap.rb

@@ -14,7 +14,7 @@
   refresh_interval: 2,
   metrics_interval: 2,
   retry_limit: 2,
-  bootstrapper: Unleash::Bootstrap::FromFile.new('./examples/default-toggles.json')
+  bootstrap_data: Unleash::Bootstrap::FromFile.new('./examples/default-toggles.json').read
 )
 
 feature_name = "featureX"

lib/unleash/bootstrap/base.rb

@@ -7,12 +7,6 @@ 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

@@ -1,17 +1,9 @@
 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)
+      def self.read(file_path)
+        File.read(file_path)
       end
     end
   end

lib/unleash/bootstrap/from_uri.rb

@@ -1,19 +1,14 @@
 module Unleash
   module Bootstrap
     class FromUri < Base
-      attr_accessor :uri, :headers
-
-      # @param uri [String]
+      # @param url [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 self.read(url, headers = nil)
+        response = Unleash::Util::Http.get(URI.parse(url), nil, headers)
+
+        return nil if response.code != '200'
 
-      def read
-        response = Unleash::Util::Http.get(self.uri, nil, self.headers)
-        bootstrap_hash = JSON.parse(response.body)
-        extract_features(bootstrap_hash)
+        response.body
       end
     end
   end

lib/unleash/client.rb

@@ -18,8 +18,9 @@ def initialize(*opts)
       Unleash.logger = Unleash.configuration.logger.clone
       Unleash.logger.level = Unleash.configuration.log_level
 
+      Unleash.toggle_fetcher = Unleash::ToggleFetcher.new
       if Unleash.configuration.disable_client
-        Unleash.logger.warn "Unleash::Client is disabled! Will only return default results!"
+        Unleash.logger.warn "Unleash::Client is disabled! Will only return default (or bootstrapped if available) results!"
         return
       end
 
@@ -37,11 +38,6 @@ def is_enabled?(feature, context = nil, default_value_param = false, &fallback_b
                         default_value_param
                       end
 
-      if Unleash.configuration.disable_client
-        Unleash.logger.warn "unleash_client is disabled! Always returning #{default_value} for feature #{feature}!"
-        return default_value
-      end
-
       toggle_as_hash = Unleash&.toggles&.select{ |toggle| toggle['name'] == feature }&.first
 
       if toggle_as_hash.nil?
@@ -121,7 +117,6 @@ def info
     end
 
     def start_toggle_fetcher
-      Unleash.toggle_fetcher = Unleash::ToggleFetcher.new
       self.fetcher_scheduled_executor = Unleash::ScheduledExecutor.new(
         'ToggleFetcher',
         Unleash.configuration.refresh_interval,

lib/unleash/configuration.rb

@@ -19,7 +19,7 @@ class Configuration
       :backup_file,
       :logger,
       :log_level,
-      :bootstrapper
+      :bootstrap_data
 
     def initialize(opts = {})
       ensure_valid_opts(opts)
@@ -93,7 +93,7 @@ def set_defaults
       self.retry_limit      = 5
       self.backup_file      = nil
       self.log_level        = Logger::WARN
-      self.bootstrapper     = nil
+      self.bootstrap_data   = nil
 
       self.custom_http_headers = {}
     end

lib/unleash/toggle_fetcher.rb

@@ -4,27 +4,24 @@
 
 module Unleash
   class ToggleFetcher
-    attr_accessor :toggle_cache, :toggle_lock, :toggle_resource, :etag, :retry_count, :bootstrapper
+    attr_accessor :toggle_cache, :toggle_lock, :toggle_resource, :etag, :retry_count
 
     def initialize
       self.etag = nil
       self.toggle_cache = nil
       self.toggle_lock = Mutex.new
       self.toggle_resource = ConditionVariable.new
       self.retry_count = 0
-      self.bootstrapper = Unleash.configuration.bootstrapper
 
-      # start by fetching synchronously, and failing back to reading the backup file.
       begin
-        if self.bootstrapper.nil?
-          fetch
-        else
-          # if the consumer provides a bootstrapper, use it!
-          synchronize_with_local_cache! self.bootstrapper.read
-          update_running_client!
-        end
+        # if bootstrap configuration is available, initialize
+        bootstrap unless Unleash.configuration.bootstrap_data.nil?
+
+        # if the client is enabled, fetch synchronously
+        fetch unless Unleash.configuration.disable_client
       rescue StandardError => e
-        Unleash.logger.warn "ToggleFetcher was unable to fetch from the network or bootstrap, attempting to read from backup file."
+        # fail back to reading the backup file
+        Unleash.logger.warn "ToggleFetcher was unable to fetch from the network, attempting to read from backup file."
         Unleash.logger.debug "Exception Caught: #{e}"
         read!
       end
@@ -43,6 +40,8 @@ def toggles
     # rename to refresh_from_server!  ??
     def fetch
       Unleash.logger.debug "fetch()"
+      return if Unleash.configuration.disable_client
+
       response = Unleash::Util::Http.get(Unleash.configuration.fetch_toggles_uri, etag)
 
       if response.code == '304'
@@ -53,14 +52,7 @@ def fetch
       end
 
       self.etag = response['ETag']
-      response_hash = JSON.parse(response.body)
-
-      if response_hash['version'] >= 1
-        features = response_hash['features']
-      else
-        raise NotImplemented, "Version of features provided by unleash server" \
-          " is unsupported by this client."
-      end
+      features = get_features(response.body)
 
       # always synchronize with the local cache when fetching:
       synchronize_with_local_cache!(features)
@@ -133,5 +125,24 @@ def read!
         file&.close
       end
     end
+
+    def bootstrap
+      features = get_features(Unleash.configuration.bootstrap_data)
+
+      synchronize_with_local_cache! features
+      update_running_client!
+
+      # reset Unleash.configuration.bootstrap_data to free up memory, as we will never use it again
+      Unleash.configuration.bootstrap_data = nil
+    end
+
+    # @param response_body [String]
+    def get_features(response_body)
+      response_hash = JSON.parse(response_body)
+      return response_hash['features'] if response_hash['version'] >= 1
+
+      raise NotImplemented, "Version of features provided by unleash server" \
+        " is unsupported by this client."
+    end
   end
 end

spec/unleash/bootstrap-resources/features-v1.json

@@ -1,43 +1,14 @@
-
 {
-    "version": 1,
-    "features": [
+  "version": 1,
+  "features": [
     {
-        "name": "featureX",
-        "enabled": true,
-        "strategies": [
-            {
-                "name": "default"
-            }
-        ]
-    },
-    {
-        "name": "featureY",
-        "enabled": false,
-        "strategies": [
-            {
-                "name": "baz",
-                "parameters": {
-                    "foo": "bar"
-                }
-            }
-        ]
-
-    },
-    {
-        "name": "featureZ",
-        "enabled": true,
-        "strategies": [
-            {
-                "name": "default"
-            },
-            {
-                "name": "hola",
-                "parameters": {
-                    "name": "val"
-                }
-            }
-        ]
-
+      "name": "featureX",
+      "enabled": true,
+      "strategies": [
+        {
+          "name": "default"
+        }
+      ]
     }
-]}
+  ]
+}

spec/unleash/bootstrap/from_file_spec.rb

@@ -13,10 +13,12 @@
   it 'loads bootstrap toggle correctly from file' do
     bootstrap_file = './spec/unleash/bootstrap-resources/features-v1.json'
 
-    bootstrapper = Unleash::Bootstrap::FromFile.new(bootstrap_file)
+    bootstrap_contents = Unleash::Bootstrap::FromFile.read(bootstrap_file)
+    bootstrap_features = JSON.parse(bootstrap_contents)['features']
+
     file_contents = File.open(bootstrap_file).read
     file_features = JSON.parse(file_contents)['features']
 
-    expect(bootstrapper.read).to include_json(file_features)
+    expect(bootstrap_features).to include_json(file_features)
   end
 end

spec/unleash/bootstrap/from_uri_spec.rb

@@ -19,8 +19,9 @@
       )
       .to_return(status: 200, body: file_contents, headers: {})
 
-    bootstrapper = Unleash::Bootstrap::FromUri.new('http://test-url/bootstrap-goodness', {})
+    bootstrap_contents = Unleash::Bootstrap::FromUri.read('http://test-url/bootstrap-goodness', {})
+    bootstrap_features = JSON.parse(bootstrap_contents)['features']
 
-    expect(bootstrapper.read).to include_json(file_features)
+    expect(bootstrap_features).to include_json(file_features)
   end
 end