Introduce SerializationDepth value object to replace primitive obsession (#13) get_serialization_depth_for_class was doing type-checking (is Integer or Hash?), key-coercion (symbol vs string), and falling back to a hardcoded default — all inline. Extract that logic into Observable::SerializationDepth#for_class, making Instrumenter unaware of how depth config is shaped. https://claude.ai/code/session_01KWZUse79XR68i6nGa8VgTu Co-authored-by: Claude <noreply@anthropic.com>

lib/observable/instrumenter.rb

@@ -1,5 +1,6 @@
 require "opentelemetry/sdk"
 require_relative "configuration"
+require_relative "serialization_depth"
 
 module Observable
   class Instrumenter
@@ -8,6 +9,7 @@ class Instrumenter
     def initialize(tracer: nil, config: nil)
       @config = config || Configuration.config
       @tracer = tracer || OpenTelemetry.tracer_provider.tracer(@config.tracer_name)
+      @serialization_depth = SerializationDepth.new(@config.serialization_depth)
     end
 
     def instrument(caller_binding = nil, &block)
@@ -52,7 +54,7 @@ def extract_namespace_from_path(file_path)
       return "UnknownClass" if file_name.empty?
 
       file_name.split("_").map(&:capitalize).join
-    rescue
+    rescue StandardError
       "UnknownClass"
     end
 
@@ -65,14 +67,14 @@ def extract_actual_class_name
           else
             caller_self.class.name
           end
-        rescue
+        rescue StandardError
           extract_namespace_from_path(@caller_binding.eval("__FILE__"))
         end
       else
         caller_location = find_caller_location
         extract_namespace_from_path(caller_location.path)
       end
-    rescue
+    rescue StandardError
       "UnknownClass"
     end
 
@@ -82,28 +84,20 @@ def determine_if_class_method
       begin
         caller_self = @caller_binding.eval("self")
         caller_self.is_a?(Class)
-      rescue
+      rescue StandardError
         false
       end
     end
 
     def create_instrumented_span(caller_info, &block)
       separator = caller_info.is_class_method ? "." : "#"
-
-      if caller_info.method_name.include?("#") || caller_info.method_name.include?(".")
-        span_name = "#{caller_info.namespace}#{separator}#{caller_info.method_name.split(/[#.]/).last}"
-        function_name = "#{caller_info.namespace}#{separator}#{caller_info.method_name.split(/[#.]/).last}"
-        method_name_only = caller_info.method_name.split(/[#.]/).last
-      else
-        span_name = "#{caller_info.namespace}#{separator}#{caller_info.method_name}"
-        function_name = "#{caller_info.namespace}#{separator}#{caller_info.method_name}"
-        method_name_only = caller_info.method_name
-      end
+      method_name_only = caller_info.method_name.split(/[#.]/).last
+      qualified_name = "#{caller_info.namespace}#{separator}#{method_name_only}"
 
       @last_captured_method_name = method_name_only
       @last_captured_namespace = caller_info.namespace
-      @tracer.in_span(span_name) do |span|
-        set_span_attributes(span, caller_info, function_name)
+      @tracer.in_span(qualified_name) do |span|
+        set_span_attributes(span, caller_info, qualified_name)
 
         begin
           result = block.call
@@ -143,7 +137,7 @@ def set_span_attributes(span, caller_info, function_name)
       end
     end
 
-    def serialize_argument(span, attribute_prefix, value, param_name = nil, depth = 0)
+    def serialize_argument(span, attribute_prefix, value, param_name = nil, depth = 0, max_depth = nil)
       if param_name && should_filter_pii?(param_name)
         span.set_attribute(attribute_prefix, "[FILTERED]")
         return
@@ -155,29 +149,11 @@ def serialize_argument(span, attribute_prefix, value, param_name = nil, depth =
       when NilClass
         span.set_attribute(attribute_prefix, "nil")
       when Hash
-        serialize_hash(span, attribute_prefix, value, depth)
+        serialize_hash(span, attribute_prefix, value, depth, max_depth)
       when Array
-        serialize_array(span, attribute_prefix, value, depth)
+        serialize_array(span, attribute_prefix, value, depth, max_depth)
       else
-        serialize_object(span, attribute_prefix, value, depth)
-      end
-    end
-
-    def serialize_argument_with_custom_depth(span, attribute_prefix, value, custom_max_depth, param_name = nil, depth = 0)
-      if param_name && should_filter_pii?(param_name)
-        span.set_attribute(attribute_prefix, "[FILTERED]")
-        return
-      end
-
-      case value
-      when String, Numeric, TrueClass, FalseClass, NilClass
-        span.set_attribute(attribute_prefix, value)
-      when Hash
-        serialize_hash_with_custom_depth(span, attribute_prefix, value, custom_max_depth, depth)
-      when Array
-        serialize_array_with_custom_depth(span, attribute_prefix, value, custom_max_depth, depth)
-      else
-        serialize_object_with_custom_depth(span, attribute_prefix, value, custom_max_depth, depth)
+        serialize_object(span, attribute_prefix, value, depth, max_depth)
       end
     end
 
@@ -190,89 +166,38 @@ def serialize_return_value(span, value)
       when String, Numeric, TrueClass, FalseClass
         span.set_attribute("code.return", value)
       when Hash
-        serialize_hash(span, "code.return", value, 2)
+        serialize_hash(span, "code.return", value, DEFAULT_SERIALIZATION_DEPTH)
       when Array
-        serialize_array(span, "code.return", value, 2)
+        serialize_array(span, "code.return", value, DEFAULT_SERIALIZATION_DEPTH)
       else
-        serialize_object(span, "code.return", value, 2)
+        serialize_object(span, "code.return", value, DEFAULT_SERIALIZATION_DEPTH)
       end
     end
 
-    def serialize_hash(span, prefix, hash, depth = 0)
-      max_depth = get_serialization_depth_for_class("Hash")
+    def serialize_hash(span, prefix, hash, depth = 0, max_depth = nil)
+      max_depth ||= get_serialization_depth_for_class("Hash")
       return if depth > max_depth
 
       hash.each do |key, value|
         key_str = key.to_s
         next if should_filter_pii?(key_str)
-        serialize_argument(span, "#{prefix}.#{key_str}", value, nil, depth + 1)
-      end
-    end
-
-    def serialize_hash_with_custom_depth(span, prefix, hash, custom_max_depth, depth = 0)
-      return if depth > custom_max_depth
-
-      hash.each do |key, value|
-        key_str = key.to_s
-        next if should_filter_pii?(key_str)
-        serialize_argument_with_custom_depth(span, "#{prefix}.#{key_str}", value, custom_max_depth, nil, depth + 1)
+        serialize_argument(span, "#{prefix}.#{key_str}", value, nil, depth + 1, max_depth)
       end
     end
 
-    def serialize_array_with_custom_depth(span, prefix, array, custom_max_depth, depth = 0)
-      return if depth > custom_max_depth
-
-      items_to_process = [array.length, 10].min
-      array.first(items_to_process).each_with_index do |item, index|
-        serialize_argument_with_custom_depth(span, "#{prefix}.#{index}", item, custom_max_depth, nil, depth + 1)
-      end
-    end
-
-    def serialize_object_with_custom_depth(span, prefix, obj, custom_max_depth, depth = 0)
-      if depth >= custom_max_depth
-        span.set_attribute("#{prefix}.class", obj.class.name)
-        span.set_attribute(prefix, obj.to_s)
-        return
-      end
-
-      span.set_attribute("#{prefix}.class", obj.class.name)
-
-      formatter = find_formatter_for_class(obj.class.name)
-
-      if formatter && obj.respond_to?(formatter)
-        result = obj.send(formatter)
-        if result.is_a?(Hash)
-          serialize_hash_with_custom_depth(span, prefix, result, custom_max_depth, depth)
-          return
-        end
-      end
-
-      default_formatter = @config.formatters[:default]
-      if default_formatter && obj.respond_to?(default_formatter)
-        result = obj.send(default_formatter)
-        if result.is_a?(Hash)
-          serialize_hash_with_custom_depth(span, prefix, result, custom_max_depth, depth)
-          return
-        end
-      end
-
-      span.set_attribute(prefix, obj.to_s)
-    end
-
-    def serialize_array(span, prefix, array, depth = 0)
-      max_depth = get_serialization_depth_for_class("Array")
+    def serialize_array(span, prefix, array, depth = 0, max_depth = nil)
+      max_depth ||= get_serialization_depth_for_class("Array")
       return if depth > max_depth
 
-      items_to_process = [array.length, 10].min
+      items_to_process = [array.length, MAX_ARRAY_ITEMS].min
       array.first(items_to_process).each_with_index do |item, index|
-        serialize_argument(span, "#{prefix}.#{index}", item, nil, depth + 1)
+        serialize_argument(span, "#{prefix}.#{index}", item, nil, depth + 1, max_depth)
       end
     end
 
-    def serialize_object(span, prefix, obj, depth = 0)
-      max_depth = get_serialization_depth_for_class(obj.class.name)
+    def serialize_object(span, prefix, obj, depth = 0, max_depth = nil)
+      max_depth ||= get_serialization_depth_for_class(obj.class.name)
 
-      # If we've reached the depth limit for this class, just set the class name
       if depth >= max_depth
         span.set_attribute("#{prefix}.class", obj.class.name)
         span.set_attribute(prefix, obj.to_s)
@@ -286,9 +211,7 @@ def serialize_object(span, prefix, obj, depth = 0)
       if formatter && obj.respond_to?(formatter)
         result = obj.send(formatter)
         if result.is_a?(Hash)
-          # When object converts to hash, the hash starts fresh at depth 0
-          # but we need to enforce the object's depth limit
-          serialize_hash_with_custom_depth(span, prefix, result, max_depth, 0)
+          serialize_hash(span, prefix, result, 0, max_depth)
           return
         end
       end
@@ -297,9 +220,7 @@ def serialize_object(span, prefix, obj, depth = 0)
       if default_formatter && obj.respond_to?(default_formatter)
         result = obj.send(default_formatter)
         if result.is_a?(Hash)
-          # When object converts to hash, the hash starts fresh at depth 0
-          # but we need to enforce the object's depth limit
-          serialize_hash_with_custom_depth(span, prefix, result, max_depth, 0)
+          serialize_hash(span, prefix, result, 0, max_depth)
           return
         end
       end
@@ -312,11 +233,7 @@ def find_formatter_for_class(class_name)
     end
 
     def get_serialization_depth_for_class(class_name)
-      if @config.serialization_depth.is_a?(Integer)
-        return @config.serialization_depth
-      end
-
-      @config.serialization_depth[class_name] || @config.serialization_depth[:default] || @config.serialization_depth["default"] || 2
+      @serialization_depth.for_class(class_name)
     end
 
     def should_filter_pii?(param_name)
@@ -353,7 +270,7 @@ def extract_from_binding
         extract_local_variables_with_numeric_indexing(args)
 
         args
-      rescue
+      rescue StandardError
         {}
       end
 

lib/observable/persistence/span_repo.rb

@@ -130,12 +130,7 @@ def get_value(hash, key)
       end
 
       def colorize_trace_header(trace_id)
-        # Use the same color constants from Span
-        cyan = "\e[36m"
-        bold = "\e[1m"
-        reset = "\e[0m"
-
-        "#{cyan}#{bold}#{trace_id}#{reset}"
+        "#{Span::CYAN}#{Span::BOLD}#{trace_id}#{Span::RESET}"
       end
     end
   end

lib/observable/serialization_depth.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+module Observable
+  class SerializationDepth
+    DEFAULT_DEPTH = 2
+
+    def initialize(config)
+      @config = config
+    end
+
+    def for_class(class_name)
+      if @config.is_a?(Integer)
+        @config
+      else
+        @config[class_name] || @config[:default] || @config["default"] || DEFAULT_DEPTH
+      end
+    end
+  end
+end

lib/observable/structured_error.rb

@@ -45,7 +45,7 @@ def self.safe_message(error)
       else
         ""
       end
-    rescue
+    rescue StandardError
       ""
     end
 
@@ -63,7 +63,7 @@ def self.safe_type(error)
       end
 
       error.class.name
-    rescue
+    rescue StandardError
       error.class.name
     end
 
@@ -77,7 +77,7 @@ def self.safe_context(error)
       else
         {}
       end
-    rescue
+    rescue StandardError
       {}
     end
 
@@ -92,7 +92,7 @@ def self.try_custom_converter(error)
 
       result = begin
         converter.call(error)
-      rescue
+      rescue StandardError
         nil
       end