From e33e8cd0c6dfd7a5a883f813c089ccda41c7777b Mon Sep 17 00:00:00 2001
From: kwasniew <kwasniewski.mateusz@gmail.com>
Date: Thu, 28 Aug 2025 14:31:10 +0200
Subject: [PATCH 1/5] feat: read backup file and bootstrap for streaming

---
 lib/unleash/backup_file_reader.rb        | 30 ++++++++++++++++++++++++
 lib/unleash/streaming_client_executor.rb | 29 +++++++++++++++++++++++
 lib/unleash/toggle_fetcher.rb            | 25 ++++----------------
 3 files changed, 64 insertions(+), 20 deletions(-)
 create mode 100644 lib/unleash/backup_file_reader.rb

diff --git a/lib/unleash/backup_file_reader.rb b/lib/unleash/backup_file_reader.rb
new file mode 100644
index 0000000..ca697c3
--- /dev/null
+++ b/lib/unleash/backup_file_reader.rb
@@ -0,0 +1,30 @@
+require 'unleash/configuration'
+require 'json'
+
+module Unleash
+  class BackupFileReader
+    def self.read!
+      Unleash.logger.debug "read!()"
+
+      backup_file = Unleash.configuration.backup_file
+      return nil unless File.exist?(backup_file)
+
+      File.read(backup_file)
+    rescue IOError => e
+      # :nocov:
+      Unleash.logger.error "Unable to read the backup_file: #{e}"
+      # :nocov:
+      nil
+    rescue JSON::ParserError => e
+      # :nocov:
+      Unleash.logger.error "Unable to parse JSON from existing backup_file: #{e}"
+      # :nocov:
+      nil
+    rescue StandardError => e
+      # :nocov:
+      Unleash.logger.error "Unable to extract valid data from backup_file. Exception thrown: #{e}"
+      # :nocov:
+      nil
+    end
+  end
+end
diff --git a/lib/unleash/streaming_client_executor.rb b/lib/unleash/streaming_client_executor.rb
index a0c4085..a6f87d2 100644
--- a/lib/unleash/streaming_client_executor.rb
+++ b/lib/unleash/streaming_client_executor.rb
@@ -1,4 +1,6 @@
 require 'unleash/streaming_event_processor'
+require 'unleash/bootstrap/handler'
+require 'unleash/backup_file_reader'
 require 'unleash/util/event_source_wrapper'
 
 module Unleash
@@ -10,6 +12,20 @@ def initialize(name, engine)
       self.event_source = nil
       self.event_processor = Unleash::StreamingEventProcessor.new(engine)
       self.running = false
+
+      begin
+        # if bootstrap configuration is available, initialize. Otherwise read backup file
+        if Unleash.configuration.use_bootstrap?
+          bootstrap(engine)
+        else
+          read_backup_file!(engine)
+        end
+      rescue StandardError => e
+        # fail back to reading the backup file
+        Unleash.logger.warn "StreamingClientExecutor was unable to initialize, attempting to read from backup file."
+        Unleash.logger.debug "Exception Caught: #{e}"
+        read_backup_file!(engine)
+      end
     end
 
     def run(&_block)
@@ -81,5 +97,18 @@ def handle_event(event)
       Unleash.logger.error "Streaming client #{self.name} threw exception #{e.class}: '#{e}'"
       Unleash.logger.debug "stacktrace: #{e.backtrace}"
     end
+
+    def read_backup_file!(engine)
+      backup_data = Unleash::BackupFileReader.read!
+      engine.take_state(backup_data) if backup_data
+    end
+
+    def bootstrap(engine)
+      bootstrap_payload = Unleash::Bootstrap::Handler.new(Unleash.configuration.bootstrap_config).retrieve_toggles
+      engine.take_state(bootstrap_payload)
+
+      # reset Unleash.configuration.bootstrap_data to free up memory, as we will never use it again
+      Unleash.configuration.bootstrap_config = nil
+    end
   end
 end
diff --git a/lib/unleash/toggle_fetcher.rb b/lib/unleash/toggle_fetcher.rb
index ebcb3be..e7a56c1 100755
--- a/lib/unleash/toggle_fetcher.rb
+++ b/lib/unleash/toggle_fetcher.rb
@@ -1,6 +1,7 @@
 require 'unleash/configuration'
 require 'unleash/bootstrap/handler'
 require 'unleash/backup_file_writer'
+require 'unleash/backup_file_reader'
 require 'net/http'
 require 'json'
 require 'yggdrasil_engine'
@@ -27,7 +28,7 @@ def initialize(engine)
         # 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!
+        read_backup_file!
       end
 
       # once initialized, somewhere else you will want to start a loop with fetch()
@@ -71,25 +72,9 @@ def update_engine_state!(toggle_data)
       Unleash.logger.error "Failed to hydrate state: #{e.backtrace}"
     end
 
-    def read!
-      Unleash.logger.debug "read!()"
-      backup_file = Unleash.configuration.backup_file
-      return nil unless File.exist?(backup_file)
-
-      backup_data = File.read(backup_file)
-      update_engine_state!(backup_data)
-    rescue IOError => e
-      # :nocov:
-      Unleash.logger.error "Unable to read the backup_file: #{e}"
-      # :nocov:
-    rescue JSON::ParserError => e
-      # :nocov:
-      Unleash.logger.error "Unable to parse JSON from existing backup_file: #{e}"
-      # :nocov:
-    rescue StandardError => e
-      # :nocov:
-      Unleash.logger.error "Unable to extract valid data from backup_file. Exception thrown: #{e}"
-      # :nocov:
+    def read_backup_file!
+      backup_data = Unleash::BackupFileReader.read!
+      update_engine_state!(backup_data) if backup_data
     end
 
     def bootstrap

From 29592975fcb41a8724ed75639770cc03f500a82d Mon Sep 17 00:00:00 2001
From: kwasniew <kwasniewski.mateusz@gmail.com>
Date: Thu, 28 Aug 2025 16:11:45 +0200
Subject: [PATCH 2/5] test: reading backup and bootstrap

---
 .../unleash/streaming_client_executor_spec.rb | 167 ++++++++++++++++++
 1 file changed, 167 insertions(+)
 create mode 100644 spec/unleash/streaming_client_executor_spec.rb

diff --git a/spec/unleash/streaming_client_executor_spec.rb b/spec/unleash/streaming_client_executor_spec.rb
new file mode 100644
index 0000000..1071b61
--- /dev/null
+++ b/spec/unleash/streaming_client_executor_spec.rb
@@ -0,0 +1,167 @@
+RSpec.describe Unleash::StreamingClientExecutor do
+  unless RUBY_ENGINE == 'jruby'
+    before do
+      Unleash.configure do |config|
+        config.url      = 'http://streaming-test-url/'
+        config.app_name = 'streaming-test-app'
+        config.instance_id = 'rspec/streaming'
+        config.disable_metrics = true
+        config.experimental_mode = { type: 'streaming' }
+      end
+
+      WebMock.stub_request(:post, "http://streaming-test-url/client/register")
+        .to_return(status: 200, body: "", headers: {})
+
+      Unleash.logger = Unleash.configuration.logger
+    end
+
+    after do
+      WebMock.reset!
+      File.delete(Unleash.configuration.backup_file) if File.exist?(Unleash.configuration.backup_file)
+      
+      # Reset configuration to prevent interference with other tests
+      Unleash.configuration.bootstrap_config = nil
+      Unleash.configuration.experimental_mode = nil
+      Unleash.configuration.disable_metrics = false
+    end
+
+    describe '.new' do
+      let(:engine) { YggdrasilEngine.new }
+      let(:executor_name) { 'streaming_client_executor_spec' }
+
+      context 'when there are problems connecting to streaming endpoint' do
+        let(:backup_toggles) do
+          {
+            version: 1,
+            features: [
+              {
+                name: "backup-feature",
+                description: "Feature from backup",
+                enabled: true,
+                strategies: [{
+                  "name": "default"
+                }]
+              }
+            ]
+          }
+        end
+
+        let(:streaming_executor) { described_class.new(executor_name, engine) }
+
+        before do
+          backup_file = Unleash.configuration.backup_file
+
+          # manually create a stub cache on disk, so we can test that we read it correctly later.
+          File.open(backup_file, "w") do |file|
+            file.write(backup_toggles.to_json)
+          end
+
+          # Simulate streaming connection failure
+          WebMock.stub_request(:get, "http://streaming-test-url/client/streaming")
+            .to_return(status: 500, body: "Internal Server Error", headers: {})
+
+          streaming_executor
+        end
+
+        it 'reads the backup file for values' do
+          enabled = engine.enabled?('backup-feature', {})
+          expect(enabled).to eq(true)
+        end
+      end
+
+      context 'when bootstrap is configured' do
+        let(:bootstrap_data) do
+          {
+            version: 1,
+            features: [
+              {
+                name: "bootstrap-feature",
+                enabled: true,
+                strategies: [{ name: "default" }]
+              }
+            ]
+          }
+        end
+
+        let(:bootstrap_config) do
+          Unleash::Bootstrap::Configuration.new({
+            'data' => bootstrap_data.to_json
+          })
+        end
+
+        let(:streaming_executor) { described_class.new(executor_name, engine) }
+
+        before do
+          Unleash.configuration.bootstrap_config = bootstrap_config
+
+          # Streaming connection might succeed or fail, doesn't matter for bootstrap
+          WebMock.stub_request(:get, "http://streaming-test-url/client/streaming")
+            .to_return(status: 200, body: "", headers: {})
+
+          streaming_executor
+        end
+
+        after do
+          Unleash.configuration.bootstrap_config = nil
+        end
+
+        it 'uses bootstrap data on initialization' do
+          enabled = engine.enabled?('bootstrap-feature', {})
+          expect(enabled).to eq(true)
+        end
+
+        it 'clears bootstrap config after use' do
+          expect(Unleash.configuration.bootstrap_config).to be_nil
+        end
+      end
+
+      context 'when bootstrap fails and backup file exists' do
+        let(:invalid_bootstrap_config) do
+          Unleash::Bootstrap::Configuration.new({
+            'data' => 'invalid json'
+          })
+        end
+
+        let(:fallback_toggles) do
+          {
+            version: 1,
+            features: [
+              {
+                name: "fallback-feature",
+                enabled: true,
+                strategies: [{ name: "default" }]
+              }
+            ]
+          }
+        end
+
+        let(:streaming_executor) { described_class.new(executor_name, engine) }
+
+        before do
+          backup_file = Unleash.configuration.backup_file
+
+          File.open(backup_file, "w") do |file|
+            file.write(fallback_toggles.to_json)
+          end
+
+          Unleash.configuration.bootstrap_config = invalid_bootstrap_config
+
+          # Streaming connection failure doesn't matter here
+          WebMock.stub_request(:get, "http://streaming-test-url/client/streaming")
+            .to_return(status: 500, body: "", headers: {})
+
+          streaming_executor
+        end
+
+        after do
+          Unleash.configuration.bootstrap_config = nil
+        end
+
+        it 'falls back to reading backup file when bootstrap fails' do
+          enabled = engine.enabled?('fallback-feature', {})
+          expect(enabled).to eq(true)
+        end
+      end
+    end
+  end
+end
\ No newline at end of file

From 06908711bd18146f3f58716517d9220a9627c9e2 Mon Sep 17 00:00:00 2001
From: kwasniew <kwasniewski.mateusz@gmail.com>
Date: Thu, 28 Aug 2025 16:16:00 +0200
Subject: [PATCH 3/5] test: reading backup and bootstrap

---
 spec/unleash/streaming_client_executor_spec.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/spec/unleash/streaming_client_executor_spec.rb b/spec/unleash/streaming_client_executor_spec.rb
index 1071b61..dcd72e4 100644
--- a/spec/unleash/streaming_client_executor_spec.rb
+++ b/spec/unleash/streaming_client_executor_spec.rb
@@ -18,7 +18,7 @@
     after do
       WebMock.reset!
       File.delete(Unleash.configuration.backup_file) if File.exist?(Unleash.configuration.backup_file)
-      
+
       # Reset configuration to prevent interference with other tests
       Unleash.configuration.bootstrap_config = nil
       Unleash.configuration.experimental_mode = nil
@@ -164,4 +164,4 @@
       end
     end
   end
-end
\ No newline at end of file
+end

From 425c1c47f0618ca8fdc71058cbd60b77fbbaf6e8 Mon Sep 17 00:00:00 2001
From: kwasniew <kwasniewski.mateusz@gmail.com>
Date: Thu, 28 Aug 2025 16:21:55 +0200
Subject: [PATCH 4/5] test: reading backup and bootstrap

---
 spec/unleash/streaming_client_executor_spec.rb | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/spec/unleash/streaming_client_executor_spec.rb b/spec/unleash/streaming_client_executor_spec.rb
index dcd72e4..ad772c5 100644
--- a/spec/unleash/streaming_client_executor_spec.rb
+++ b/spec/unleash/streaming_client_executor_spec.rb
@@ -1,4 +1,6 @@
 RSpec.describe Unleash::StreamingClientExecutor do
+  subject(:streaming_executor) { Unleash::StreamingClientExecutor.new(executor_name, engine) }
+
   unless RUBY_ENGINE == 'jruby'
     before do
       Unleash.configure do |config|
@@ -39,15 +41,13 @@
                 description: "Feature from backup",
                 enabled: true,
                 strategies: [{
-                  "name": "default"
+                  name: "default"
                 }]
               }
             ]
           }
         end
 
-        let(:streaming_executor) { described_class.new(executor_name, engine) }
-
         before do
           backup_file = Unleash.configuration.backup_file
 
@@ -56,7 +56,6 @@
             file.write(backup_toggles.to_json)
           end
 
-          # Simulate streaming connection failure
           WebMock.stub_request(:get, "http://streaming-test-url/client/streaming")
             .to_return(status: 500, body: "Internal Server Error", headers: {})
 
@@ -89,12 +88,9 @@
           })
         end
 
-        let(:streaming_executor) { described_class.new(executor_name, engine) }
-
         before do
           Unleash.configuration.bootstrap_config = bootstrap_config
 
-          # Streaming connection might succeed or fail, doesn't matter for bootstrap
           WebMock.stub_request(:get, "http://streaming-test-url/client/streaming")
             .to_return(status: 200, body: "", headers: {})
 
@@ -135,8 +131,6 @@
           }
         end
 
-        let(:streaming_executor) { described_class.new(executor_name, engine) }
-
         before do
           backup_file = Unleash.configuration.backup_file
 
@@ -146,7 +140,6 @@
 
           Unleash.configuration.bootstrap_config = invalid_bootstrap_config
 
-          # Streaming connection failure doesn't matter here
           WebMock.stub_request(:get, "http://streaming-test-url/client/streaming")
             .to_return(status: 500, body: "", headers: {})
 

From 3ab22d685b3eb5c63518a3de8cb4fd91721c38ae Mon Sep 17 00:00:00 2001
From: kwasniew <kwasniewski.mateusz@gmail.com>
Date: Wed, 3 Sep 2025 16:04:40 +0200
Subject: [PATCH 5/5] chore: apply PR feedback

---
 lib/unleash/backup_file_reader.rb        | 6 ------
 lib/unleash/streaming_client_executor.rb | 2 +-
 lib/unleash/toggle_fetcher.rb            | 2 +-
 3 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/lib/unleash/backup_file_reader.rb b/lib/unleash/backup_file_reader.rb
index ca697c3..f2a3831 100644
--- a/lib/unleash/backup_file_reader.rb
+++ b/lib/unleash/backup_file_reader.rb
@@ -1,5 +1,4 @@
 require 'unleash/configuration'
-require 'json'
 
 module Unleash
   class BackupFileReader
@@ -15,11 +14,6 @@ def self.read!
       Unleash.logger.error "Unable to read the backup_file: #{e}"
       # :nocov:
       nil
-    rescue JSON::ParserError => e
-      # :nocov:
-      Unleash.logger.error "Unable to parse JSON from existing backup_file: #{e}"
-      # :nocov:
-      nil
     rescue StandardError => e
       # :nocov:
       Unleash.logger.error "Unable to extract valid data from backup_file. Exception thrown: #{e}"
diff --git a/lib/unleash/streaming_client_executor.rb b/lib/unleash/streaming_client_executor.rb
index a6f87d2..b194e94 100644
--- a/lib/unleash/streaming_client_executor.rb
+++ b/lib/unleash/streaming_client_executor.rb
@@ -21,7 +21,7 @@ def initialize(name, engine)
           read_backup_file!(engine)
         end
       rescue StandardError => e
-        # fail back to reading the backup file
+        # fall back to reading the backup file
         Unleash.logger.warn "StreamingClientExecutor was unable to initialize, attempting to read from backup file."
         Unleash.logger.debug "Exception Caught: #{e}"
         read_backup_file!(engine)
diff --git a/lib/unleash/toggle_fetcher.rb b/lib/unleash/toggle_fetcher.rb
index e7a56c1..5d1b3c8 100755
--- a/lib/unleash/toggle_fetcher.rb
+++ b/lib/unleash/toggle_fetcher.rb
@@ -25,7 +25,7 @@ def initialize(engine)
           fetch
         end
       rescue StandardError => e
-        # fail back to reading the backup file
+        # fall 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_backup_file!