feat: allow configs to take in user provided logger instances for client logging behavior

lib/amplitude/processor.rb

@@ -87,7 +87,7 @@ def callback(events, code, message)
         @configuration.callback.call(event, code, message) if @configuration.callback.respond_to?(:call)
         event.callback(code, message)
       rescue StandardError => e
-        @configuration.logger.exception("Error callback for event #{event}: #{e.message}")
+        @configuration.logger.error("Error callback for event #{event}: #{e.message}")
       end
     end
 

lib/amplitude/timeline.rb

@@ -49,7 +49,7 @@ def flush
         @plugins[PluginType::DESTINATION].each do |destination|
           destination_futures << destination.flush
         rescue StandardError
-          logger.exception('Error for flush events')
+          logger.error('Error for flush events')
         end
       end
       destination_futures

lib/experiment/local/client.rb

@@ -14,14 +14,9 @@ class LocalEvaluationClient
     def initialize(api_key, config = nil)
       @api_key = api_key
       @config = config || LocalEvaluationConfig.new
+      @logger = @config.logger
       @flags = nil
       @flags_mutex = Mutex.new
-      @logger = Logger.new($stdout)
-      @logger.level = if @config.debug
-                        Logger::DEBUG
-                      else
-                        Logger::INFO
-                      end
       raise ArgumentError, 'Experiment API key is empty' if @api_key.nil? || @api_key.empty?
 
       @engine = Evaluation::Engine.new

lib/experiment/local/config.rb

@@ -1,3 +1,5 @@
+require 'logger'
+
 module AmplitudeExperiment
   module ServerZone
     US = 'US'.freeze
@@ -9,11 +11,17 @@ class LocalEvaluationConfig
     # Default server url
     DEFAULT_SERVER_URL = 'https://api.lab.amplitude.com'.freeze
     EU_SERVER_URL = 'https://flag.lab.eu.amplitude.com'.freeze
+    DEFAULT_LOGDEV = $stdout
+    DEFAULT_LOG_LEVEL = Logger::ERROR
 
     # Set to true to log some extra information to the console.
     # @return [Boolean] the value of debug
     attr_accessor :debug
 
+    # Set the client logger to a user defined [Logger]
+    # @return [Logger] the logger instance of the client
+    attr_accessor :logger
+
     # The server endpoint from which to request variants.
     # @return [String] the value of server url
     attr_accessor :server_url
@@ -35,16 +43,26 @@ class LocalEvaluationConfig
     attr_accessor :cohort_sync_config
 
     # @param [Boolean] debug Set to true to log some extra information to the console.
+    # @param [Logger] logger instance to be used for all client logging behavior
     # @param [String] server_url The server endpoint from which to request variants.
     # @param [String] server_zone Location of the Amplitude data center to get flags and cohorts from, US or EU
     # @param [Hash] bootstrap The value of bootstrap.
     # @param [long] flag_config_polling_interval_millis The value of flag config polling interval in million seconds.
     # @param [AssignmentConfig] assignment_config Configuration for automatically tracking assignment events after an evaluation.
     # @param [CohortSyncConfig] cohort_sync_config Configuration for downloading cohorts required for flag evaluation
-    def initialize(server_url: DEFAULT_SERVER_URL, server_zone: ServerZone::US, bootstrap: {},
-                   flag_config_polling_interval_millis: 30_000, debug: false, assignment_config: nil,
+    def initialize(server_url: DEFAULT_SERVER_URL,
+                   server_zone: ServerZone::US,
+                   bootstrap: {},
+                   flag_config_polling_interval_millis: 30_000,
+                   debug: false,
+                   logger: nil,
+                   assignment_config: nil,
                    cohort_sync_config: nil)
-      @debug = debug || false
+      @logger = logger
+      if logger.nil?
+        @logger = Logger.new(DEFAULT_LOGDEV)
+        @logger.level = debug ? Logger::DEBUG : DEFAULT_LOG_LEVEL
+      end
       @server_url = server_url
       @server_zone = server_zone
       @cohort_sync_config = cohort_sync_config

lib/experiment/remote/client.rb

@@ -13,12 +13,7 @@ class RemoteEvaluationClient
     def initialize(api_key, config = nil)
       @api_key = api_key
       @config = config || RemoteEvaluationConfig.new
-      @logger = Logger.new($stdout)
-      @logger.level = if @config.debug
-                        Logger::DEBUG
-                      else
-                        Logger::INFO
-                      end
+      @logger = @config.logger
       endpoint = "#{@config.server_url}/sdk/v2/vardata?v=0"
       @uri = URI(endpoint)
       raise ArgumentError, 'Experiment API key is empty' if @api_key.nil? || @api_key.empty?

lib/experiment/remote/config.rb

@@ -1,13 +1,21 @@
+require 'logger'
+
 module AmplitudeExperiment
   # Configuration
   class RemoteEvaluationConfig
     # Default server url
     DEFAULT_SERVER_URL = 'https://api.lab.amplitude.com'.freeze
+    DEFAULT_LOGDEV = $stdout
+    DEFAULT_LOG_LEVEL = Logger::ERROR
 
     # Set to true to log some extra information to the console.
     # @return [Boolean] the value of debug
     attr_accessor :debug
 
+    # Set the client logger to a user defined [Logger]
+    # @return [Logger] the logger instance of the client
+    attr_accessor :logger
+
     # The server endpoint from which to request variants.
     # @return [Boolean] the value of server url
     attr_accessor :server_url
@@ -43,6 +51,7 @@ class RemoteEvaluationConfig
     attr_accessor :fetch_retry_timeout_millis
 
     # @param [Boolean] debug Set to true to log some extra information to the console.
+    # @param [Logger] logger instance to be used for all client logging behavior
     # @param [String] server_url The server endpoint from which to request variants.
     # @param [Integer] connect_timeout_millis The request connection open timeout, in milliseconds, used when
     #  fetching variants triggered by calling start() or setUser().
@@ -55,10 +64,21 @@ class RemoteEvaluationConfig
     #  greater than the max, the max is used for all subsequent retries.
     # @param [Float] fetch_retry_backoff_scalar Scales the minimum backoff exponentially.
     # @param [Integer] fetch_retry_timeout_millis The request timeout for retrying fetch requests.
-    def initialize(debug: false, server_url: DEFAULT_SERVER_URL, connect_timeout_millis: 60_000, fetch_timeout_millis: 10_000, fetch_retries: 0,
-                   fetch_retry_backoff_min_millis: 500, fetch_retry_backoff_max_millis: 10_000,
-                   fetch_retry_backoff_scalar: 1.5, fetch_retry_timeout_millis: 10_000)
-      @debug = debug
+    def initialize(debug: false,
+                   logger: nil,
+                   server_url: DEFAULT_SERVER_URL,
+                   connect_timeout_millis: 60_000,
+                   fetch_timeout_millis: 10_000,
+                   fetch_retries: 0,
+                   fetch_retry_backoff_min_millis: 500,
+                   fetch_retry_backoff_max_millis: 10_000,
+                   fetch_retry_backoff_scalar: 1.5,
+                   fetch_retry_timeout_millis: 10_000)
+      @logger = logger
+      if logger.nil?
+        @logger = Logger.new(DEFAULT_LOGDEV)
+        @logger.level = debug ? Logger::DEBUG : DEFAULT_LOG_LEVEL
+      end
       @server_url = server_url
       @connect_timeout_millis = connect_timeout_millis
       @fetch_timeout_millis = fetch_timeout_millis

spec/experiment/local/client_spec.rb

@@ -27,6 +27,30 @@ def setup_stub
       it 'error if api_key is empty' do
         expect { LocalEvaluationClient.new('') }.to raise_error(ArgumentError)
       end
+
+      it 'uses custom logger when provided' do
+        custom_logger = Logger.new($stdout)
+        config = LocalEvaluationConfig.new(logger: custom_logger)
+        client = LocalEvaluationClient.new(api_key, config)
+
+        expect(client.instance_variable_get(:@logger)).to eq(custom_logger)
+      end
+
+      it 'debug flag overrides logger level to DEBUG when not provided a custom logger ' do
+        config = LocalEvaluationConfig.new(debug: true)
+        client = LocalEvaluationClient.new(api_key, config)
+
+        expect(client.instance_variable_get(:@logger).level).to eq(Logger::DEBUG)
+      end
+
+      it 'debug flag does not modify logger level when provided a custom logger' do
+        custom_logger = Logger.new($stdout)
+        custom_logger.level = Logger::WARN
+        config = LocalEvaluationConfig.new(logger: custom_logger, debug: true)
+        client = LocalEvaluationClient.new(api_key, config)
+
+        expect(client.instance_variable_get(:@logger).level).to eq(Logger::WARN)
+      end
     end
 
     describe '#evaluation' do

spec/experiment/remote/client_spec.rb

@@ -11,6 +11,30 @@ module AmplitudeExperiment
       it 'raises an error if api_key is empty' do
         expect { RemoteEvaluationClient.new('') }.to raise_error(ArgumentError)
       end
+
+      it 'uses custom logger when provided' do
+        custom_logger = Logger.new($stdout)
+        config = RemoteEvaluationConfig.new(logger: custom_logger)
+        client = RemoteEvaluationClient.new(api_key, config)
+
+        expect(client.instance_variable_get(:@logger)).to eq(custom_logger)
+      end
+
+      it 'debug flag overrides logger level to DEBUG when not provided a custom logger ' do
+        config = RemoteEvaluationConfig.new(debug: true)
+        client = RemoteEvaluationClient.new(api_key, config)
+
+        expect(client.instance_variable_get(:@logger).level).to eq(Logger::DEBUG)
+      end
+
+      it 'debug flag does not modify logger level when provided a custom logger' do
+        custom_logger = Logger.new($stdout)
+        custom_logger.level = Logger::WARN
+        config = RemoteEvaluationConfig.new(logger: custom_logger, debug: true)
+        client = RemoteEvaluationClient.new(api_key, config)
+
+        expect(client.instance_variable_get(:@logger).level).to eq(Logger::WARN)
+      end
     end
 
     response_with_key = '{"sdk-ci-test":{"key":"on","payload":"payload"}}'