fix: HTTP unknown methods

Ensures that all HTTP client gems support unknown methods as described in semantic conventions:

https://opentelemetry.io/docs/specs/semconv/http/http-spans/#http-client-span

See #1779

Author: arielvalentin

instrumentation/ethon/lib/opentelemetry/instrumentation/ethon.rb

@@ -15,5 +15,6 @@ module Ethon
   end
 end
 
+require_relative 'ethon/http_helper'
 require_relative 'ethon/instrumentation'
 require_relative 'ethon/version'

instrumentation/ethon/lib/opentelemetry/instrumentation/ethon/http_helper.rb

@@ -0,0 +1,86 @@
+# frozen_string_literal: true
+
+# Copyright The OpenTelemetry Authors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+module OpenTelemetry
+  module Instrumentation
+    module Ethon
+      # Helper module for HTTP method normalization
+      # @api private
+      module HttpHelper
+        # Lightweight struct to hold span creation attributes
+        SpanCreationAttributes = Struct.new(:span_name, :normalized_method, :original_method, keyword_init: true)
+
+        # Pre-computed mapping to avoid string allocations during normalization
+        METHOD_CACHE = {
+          'CONNECT' => 'CONNECT',
+          'DELETE' => 'DELETE',
+          'GET' => 'GET',
+          'HEAD' => 'HEAD',
+          'OPTIONS' => 'OPTIONS',
+          'PATCH' => 'PATCH',
+          'POST' => 'POST',
+          'PUT' => 'PUT',
+          'TRACE' => 'TRACE',
+          'connect' => 'CONNECT',
+          'delete' => 'DELETE',
+          'get' => 'GET',
+          'head' => 'HEAD',
+          'options' => 'OPTIONS',
+          'patch' => 'PATCH',
+          'post' => 'POST',
+          'put' => 'PUT',
+          'trace' => 'TRACE',
+          :connect => 'CONNECT',
+          :delete => 'DELETE',
+          :get => 'GET',
+          :head => 'HEAD',
+          :options => 'OPTIONS',
+          :patch => 'PATCH',
+          :post => 'POST',
+          :put => 'PUT',
+          :trace => 'TRACE'
+        }.freeze
+
+        # Pre-computed span names for old semantic conventions to avoid allocations
+        OLD_SPAN_NAMES = {
+          'CONNECT' => 'HTTP CONNECT',
+          'DELETE' => 'HTTP DELETE',
+          'GET' => 'HTTP GET',
+          'HEAD' => 'HTTP HEAD',
+          'OPTIONS' => 'HTTP OPTIONS',
+          'PATCH' => 'HTTP PATCH',
+          'POST' => 'HTTP POST',
+          'PUT' => 'HTTP PUT',
+          'TRACE' => 'HTTP TRACE'
+        }.freeze
+
+        private_constant :METHOD_CACHE, :OLD_SPAN_NAMES
+
+        # Prepares all span data for the specified semantic convention in a single call
+        # @param method [String, Symbol] The HTTP method
+        # @param semconv [Symbol] The semantic convention to use (:stable or :old)
+        # @return [SpanCreationAttributes] struct containing span_name, normalized_method, and original_method
+        def self.span_attrs_for(method, semconv: :stable)
+          normalized = METHOD_CACHE[method]
+          if normalized
+            span_name = semconv == :old ? OLD_SPAN_NAMES[normalized] : normalized
+            SpanCreationAttributes.new(
+              span_name: span_name,
+              normalized_method: normalized,
+              original_method: nil
+            )
+          else
+            SpanCreationAttributes.new(
+              span_name: 'HTTP',
+              normalized_method: '_OTHER',
+              original_method: method.to_s
+            )
+          end
+        end
+      end
+    end
+  end
+end

instrumentation/ethon/lib/opentelemetry/instrumentation/ethon/patches/dup/easy.rb

@@ -12,20 +12,11 @@ module Patches
         module Dup
           # Ethon::Easy patch for instrumentation
           module Easy
-            ACTION_NAMES_TO_HTTP_METHODS = Hash.new do |h, k|
-              # #to_s is required because user input could be symbol or string
-              h[k] = k.to_s.upcase
-            end
-            HTTP_METHODS_TO_SPAN_NAMES = Hash.new do |h, k|
-              h[k] = k.to_s
-              h[k] = 'HTTP' if k == '_OTHER'
-            end
-
             # Constant for the HTTP status range
             HTTP_STATUS_SUCCESS_RANGE = (100..399)
 
             def http_request(url, action_name, options = {})
-              @otel_method = ACTION_NAMES_TO_HTTP_METHODS[action_name]
+              @otel_method = action_name
               super
             end
 
@@ -77,12 +68,11 @@ def reset
             end
 
             def otel_before_request
-              method = '_OTHER' # Could be GET or not HTTP at all
-              method = @otel_method if instance_variable_defined?(:@otel_method) && !@otel_method.nil?
+              span_data = HttpHelper.span_attrs_for(@otel_method)
 
               @otel_span = tracer.start_span(
-                HTTP_METHODS_TO_SPAN_NAMES[method],
-                attributes: span_creation_attributes(method),
+                span_data.span_name,
+                attributes: span_creation_attributes(span_data),
                 kind: :client
               )
 
@@ -99,12 +89,12 @@ def otel_span_started?
 
             private
 
-            def span_creation_attributes(method)
-              http_method = (method == '_OTHER' ? 'N/A' : method)
+            def span_creation_attributes(span_data)
               instrumentation_attrs = {
-                'http.method' => http_method,
-                'http.request.method' => method
+                'http.method' => span_data.normalized_method,
+                'http.request.method' => span_data.normalized_method
               }
+              instrumentation_attrs['http.request.method_original'] = span_data.original_method if span_data.original_method
 
               uri = _otel_cleanse_uri(url)
               if uri

instrumentation/ethon/lib/opentelemetry/instrumentation/ethon/patches/old/easy.rb

@@ -12,17 +12,11 @@ module Patches
         module Old
           # Ethon::Easy patch for instrumentation
           module Easy
-            ACTION_NAMES_TO_HTTP_METHODS = Hash.new do |h, k|
-              # #to_s is required because user input could be symbol or string
-              h[k] = k.to_s.upcase
-            end
-            HTTP_METHODS_TO_SPAN_NAMES = Hash.new { |h, k| h[k] = "HTTP #{k}" }
-
             # Constant for the HTTP status range
             HTTP_STATUS_SUCCESS_RANGE = (100..399)
 
             def http_request(url, action_name, options = {})
-              @otel_method = ACTION_NAMES_TO_HTTP_METHODS[action_name]
+              @otel_method = action_name
               super
             end
 
@@ -73,12 +67,11 @@ def reset
             end
 
             def otel_before_request
-              method = 'N/A' # Could be GET or not HTTP at all
-              method = @otel_method if instance_variable_defined?(:@otel_method) && !@otel_method.nil?
+              span_data = HttpHelper.span_attrs_for(@otel_method, semconv: :old)
 
               @otel_span = tracer.start_span(
-                HTTP_METHODS_TO_SPAN_NAMES[method],
-                attributes: span_creation_attributes(method),
+                span_data.span_name,
+                attributes: span_creation_attributes(span_data),
                 kind: :client
               )
 
@@ -95,9 +88,9 @@ def otel_span_started?
 
             private
 
-            def span_creation_attributes(method)
+            def span_creation_attributes(span_data)
               instrumentation_attrs = {
-                'http.method' => method
+                'http.method' => span_data.normalized_method
               }
 
               uri = _otel_cleanse_uri(url)

instrumentation/ethon/lib/opentelemetry/instrumentation/ethon/patches/stable/easy.rb

@@ -12,20 +12,11 @@ module Patches
         module Stable
           # Ethon::Easy patch for instrumentation
           module Easy
-            ACTION_NAMES_TO_HTTP_METHODS = Hash.new do |h, k|
-              # #to_s is required because user input could be symbol or string
-              h[k] = k.to_s.upcase
-            end
-            HTTP_METHODS_TO_SPAN_NAMES = Hash.new do |h, k|
-              h[k] = k.to_s
-              h[k] = 'HTTP' if k == '_OTHER'
-            end
-
             # Constant for the HTTP status range
             HTTP_STATUS_SUCCESS_RANGE = (100..399)
 
             def http_request(url, action_name, options = {})
-              @otel_method = ACTION_NAMES_TO_HTTP_METHODS[action_name]
+              @otel_method = action_name
               super
             end
 
@@ -76,12 +67,11 @@ def reset
             end
 
             def otel_before_request
-              method = '_OTHER' # Could be GET or not HTTP at all
-              method = @otel_method if instance_variable_defined?(:@otel_method) && !@otel_method.nil?
+              span_data = HttpHelper.span_attrs_for(@otel_method)
 
               @otel_span = tracer.start_span(
-                HTTP_METHODS_TO_SPAN_NAMES[method],
-                attributes: span_creation_attributes(method),
+                span_data.span_name,
+                attributes: span_creation_attributes(span_data),
                 kind: :client
               )
 
@@ -98,10 +88,11 @@ def otel_span_started?
 
             private
 
-            def span_creation_attributes(method)
+            def span_creation_attributes(span_data)
               instrumentation_attrs = {
-                'http.request.method' => method
+                'http.request.method' => span_data.normalized_method
               }
+              instrumentation_attrs['http.request.method_original'] = span_data.original_method if span_data.original_method
 
               uri = _otel_cleanse_uri(url)
               if uri

instrumentation/ethon/test/opentelemetry/instrumentation/ethon/dup/instrumentation_test.rb

@@ -71,7 +71,7 @@
               easy.perform
 
               _(span.name).must_equal 'HTTP'
-              _(span.attributes['http.method']).must_equal 'N/A'
+              _(span.attributes['http.method']).must_equal '_OTHER'
               _(span.attributes['http.status_code']).must_be_nil
               _(span.attributes['http.url']).must_equal 'http://example.com/test'
               _(span.attributes['net.peer.name']).must_equal 'example.com'
@@ -92,7 +92,7 @@
               # NOTE: check the finished spans since we expect to have closed it
               span = exporter.finished_spans.first
               _(span.name).must_equal 'HTTP'
-              _(span.attributes['http.method']).must_equal 'N/A'
+              _(span.attributes['http.method']).must_equal '_OTHER'
               _(span.attributes['http.status_code']).must_be_nil
               _(span.attributes['http.url']).must_equal 'http://example.com/test'
               _(span.attributes['http.request.method']).must_equal '_OTHER'
@@ -121,7 +121,7 @@ def stub_response(options)
         it 'when response is successful' do
           stub_response(response_code: 200) do
             _(span.name).must_equal 'HTTP'
-            _(span.attributes['http.method']).must_equal 'N/A'
+            _(span.attributes['http.method']).must_equal '_OTHER'
             _(span.attributes['http.request.method']).must_equal '_OTHER'
             _(span.attributes['http.status_code']).must_equal 200
             _(span.attributes['http.response.status_code']).must_equal 200
@@ -137,7 +137,7 @@ def stub_response(options)
         it 'when response is not successful' do
           stub_response(response_code: 500) do
             _(span.name).must_equal 'HTTP'
-            _(span.attributes['http.method']).must_equal 'N/A'
+            _(span.attributes['http.method']).must_equal '_OTHER'
             _(span.attributes['http.request.method']).must_equal '_OTHER'
             _(span.attributes['http.status_code']).must_equal 500
             _(span.attributes['http.response.status_code']).must_equal 500
@@ -153,7 +153,7 @@ def stub_response(options)
         it 'when request times out' do
           stub_response(response_code: 0, return_code: :operation_timedout) do
             _(span.name).must_equal 'HTTP'
-            _(span.attributes['http.method']).must_equal 'N/A'
+            _(span.attributes['http.method']).must_equal '_OTHER'
             _(span.attributes['http.request.method']).must_equal '_OTHER'
             _(span.attributes['http.status_code']).must_be_nil
             _(span.attributes['http.response.status_code']).must_be_nil
@@ -232,7 +232,7 @@ def stub_response(options)
           end
 
           it 'cleans up @otel_method' do
-            _(easy.instance_eval { @otel_method }).must_equal 'PUT'
+            _(easy.instance_eval { @otel_method }).must_equal :put
 
             easy.reset
 
@@ -256,6 +256,32 @@ def stub_response(options)
           end
         end
       end
+
+      describe 'with unknown HTTP method' do
+        def stub_response(options)
+          easy.stub(:mirror, Ethon::Easy::Mirror.new(options)) do
+            easy.otel_before_request
+            # NOTE: perform calls complete
+            easy.complete
+
+            yield
+          end
+        end
+
+        it 'normalizes unknown HTTP methods' do
+          easy.http_request('http://example.com/purge', :purge)
+
+          stub_response(response_code: 200) do
+            _(exporter.finished_spans.size).must_equal 1
+            _(span.name).must_equal 'HTTP'
+            _(span.attributes['http.method']).must_equal '_OTHER'
+            _(span.attributes['http.url']).must_equal 'http://example.com/purge'
+            _(span.attributes['http.request.method']).must_equal '_OTHER'
+            _(span.attributes['http.request.method_original']).must_equal 'purge'
+            _(span.attributes['url.full']).must_equal 'http://example.com/purge'
+          end
+        end
+      end
     end
 
     describe 'multi' do