Remove the unless check and replace with an assertion that the file exist, small fixes, and add comments to the normalizer.rb explaining the expected usage

Author: wantsui

lib/datadog/core/normalizer.rb

@@ -3,13 +3,16 @@
 module Datadog
   module Core
     module Normalizer
+      # Normalization logic used for tag keys and values that the Trace Agent has for traces
+      # Useful for ensuring that tag keys and values are normalized consistently
+      # An use case for now is Process Tags which need to be sent across various intakes (profiling, tracing, etc.) consistently
+
       module_function
 
       INVALID_TAG_CHARACTERS = %r{[^\p{L}0-9_\-:./]}
       LEADING_INVALID_CHARS_NO_DIGITS = %r{\A[^\p{L}:]++}
       LEADING_INVALID_CHARS_WITH_DIGITS = %r{\A[^\p{L}0-9:./\-]++}
-      MAX_BYTE_SIZE = 200
-      MAX_BYTE_SIZE_BUFFER = MAX_BYTE_SIZE * 2
+      MAX_BYTE_SIZE = 200 # Represents the max tag length
       TRAILING_UNDERSCORES = %r{_++\z}
       VALID_ASCII_TAG = %r{\A[a-z:][a-z0-9:./-]*\z}
 
@@ -23,6 +26,9 @@ module Normalizer
       # - Consecutive underscores are merged into a single underscore
       # - Maximum length is 200 characters
       # If it's a tag value, allow it to start with a digit
+      # @param original_value [String] The original string
+      # @param remove_digit_start_char [Boolean] - whether to remove the leading digit (currently only used for tag values)
+      # @return [String] The normalized string
       def self.normalize(original_value, remove_digit_start_char: false)
         transformed_value = original_value.to_s.encode('UTF-8', invalid: :replace, undef: :replace)
         transformed_value.strip!

sig/datadog/core/normalizer.rbs

@@ -6,7 +6,6 @@ module Datadog
       LEADING_INVALID_CHARS_WITH_DIGITS: ::Regexp
       TRAILING_UNDERSCORES: ::Regexp
       MAX_BYTE_SIZE: ::Integer
-      MAX_BYTE_SIZE_BUFFER: ::Integer
       VALID_ASCII_TAG: ::Regexp
 
       def self.normalize: (untyped original_value, ?remove_digit_start_char: bool) -> ::String

spec/datadog/core/environment/process_spec.rb

@@ -24,10 +24,8 @@
         Dir.mktmpdir do |tmp_dir|
           Dir.chdir(tmp_dir) do
             Bundler.with_unbundled_env do
-              _, stderr, status = Open3.capture3('rails new test@_app --minimal --skip-active-record --skip-test --skip-keeps --skip-git --skip-docker')
-              unless status.success? && File.exist?("test@_app/Gemfile")
-                skip("rails new failed: #{stderr}")
-              end
+              _, _, _ = Open3.capture3('rails new test@_app --minimal --skip-active-record --skip-test --skip-keeps --skip-git --skip-docker')
+              expect(File.exist?("test@_app/Gemfile")).to be true
             end
 
             File.open("test@_app/Gemfile", 'a') do |file|

spec/datadog/core/normalizer_spec.rb

@@ -56,7 +56,7 @@
       end
     end
   end
-  
+
   describe 'Follows the normalization logic from the Trace Agent for tag values' do
     test_cases = [
       {in: '1test', out: '1test'},

spec/datadog/tracing/transport/trace_formatter_spec.rb

@@ -243,7 +243,7 @@
           expect(first_span.meta).to include(Datadog::Core::Environment::Ext::TAG_PROCESS_TAGS)
           expect(first_span.meta[Datadog::Core::Environment::Ext::TAG_PROCESS_TAGS]).to eq(Datadog::Core::Environment::Process.serialized)
         end
-        
+
         it 'does not add process tags to non first spans' do
           format!
           trace.spans.each_with_index do |span, index|