Test Configuration README example

Author: sambostock

README.md

@@ -134,6 +134,7 @@ $ ./examples/stdio_server.rb
 
 The gem can be configured using the `MCP.configure` block:
 
+<!-- SNIPPET ID: configuration -->
 ```ruby
 MCP.configure do |config|
   config.exception_reporter = ->(exception, server_context) {

test/fixtures/files/code_snippet_wrappers/readme/configuration.rb

@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+require "mcp"
+
+# Stub Bugsnag
+class Bugsnag
+  class Report
+    attr_reader :metadata
+
+    def initialize
+      @metadata = {}
+    end
+
+    def add_metadata(key, value)
+      @metadata[key] = value
+    end
+  end
+
+  class << self
+    def notify(exception)
+      report = Report.new
+      yield report
+      puts "Bugsnag notified of #{exception.inspect} with metadata #{report.metadata.inspect}"
+    end
+  end
+end
+
+require_relative "code_snippet"
+
+puts MCP::Server.new(
+  tools: [
+    MCP::Tool.define(name: "error_tool") { raise "boom" },
+  ],
+).handle_json(
+  {
+    jsonrpc: "2.0",
+    id: "1",
+    method: "tools/call",
+    params: { name: "error_tool", arguments: {} },
+  }.to_json,
+)

test/integration/readme_code_snippets_test.rb

@@ -63,6 +63,32 @@ class ReadmeCodeSnippetsTest < ActiveSupport::TestCase
     )
   end
 
+  test "Configuration example works exactly as documented in README" do
+    stdout = run_code_snippet("configuration")
+
+    request = {
+      jsonrpc: "2.0",
+      id: "1",
+      method: "tools/call",
+      params: { name: "error_tool", arguments: {} },
+    }.to_json
+
+    error = MCP::Server::RequestHandlerError.new("Internal error calling tool error_tool", request)
+    metadata = { model_context_protocol: { request: } }
+
+    response = {
+      jsonrpc: "2.0",
+      id: "1",
+      error: { code: -32603, message: "Internal error", data: "Internal error calling tool error_tool" },
+    }.to_json
+
+    assert_equal(<<~STDOUT, stdout)
+      Bugsnag notified of #{error.inspect} with metadata #{metadata.inspect}
+      Got instrumentation data {method: "tools/call", tool_name: "error_tool", error: :internal_error, duration: 1.23}
+      #{response}
+    STDOUT
+  end
+
   private
 
   def assert_json_lines(expected, actual, message = "Expected the given JSON lines")