Add XMLRPC::RackApplication (#56)

herwinw · web-flow · commit 6bf6eb4ee6c8 · 2025-04-25T06:17:23.000+09:00
This is a simple Rack application that acts as an XMLRPC server. This
can be used in any Rack compatible webserver.

There are a few gems that provide a Rack-based XMLRPC server (rack-rpc,
xmlrpc-rack_server and threez-rack-rpc), but none of these have been
updated in the past 10 years.

Implementation has mostly been copied from ModRubyServer, tests have
been inspired by the WebrickServer tests

Co-authored-by: Herwin &lt;herwinw@users.noreply.github.com&gt;
diff --git a/Gemfile b/Gemfile
@@ -6,6 +6,8 @@ group :development do
   gem "bundler"
   gem "libxml-ruby", platforms: [:ruby, :jruby]
   gem "nokogiri", platforms: [:ruby, :jruby]
+  gem "rack"
+  gem "rack-test"
   gem "rake"
   gem "test-unit"
 end
diff --git a/lib/xmlrpc/server.rb b/lib/xmlrpc/server.rb
@@ -532,6 +532,49 @@ def http_write(body, status, header)
 end
 
 
+# Implements a XML-RPC application, which works with Rack
+class RackApplication < BasicServer
+
+  # This method processes a XML-RPC method call and sends the answer
+  # back to the client.
+  def call(env)
+    length = env['CONTENT_LENGTH'].to_i
+
+    return http_error(405, "Method Not Allowed") unless env['REQUEST_METHOD'] == "POST"
+    return http_error(400, "Bad Request")        unless parse_content_type(env['CONTENT_TYPE']).first == "text/xml"
+    return http_error(411, "Length Required")    unless length > 0
+
+    req = Rack::Request.new(env)
+    data = req.body.read(length)
+
+    return http_error(400, "Bad Request")        if data.nil? or data.bytesize != length
+
+    [200, { "Content-type" => "text/xml; charset=utf-8" }, [process(data)]]
+  end
+
+
+  private
+
+  def http_error(status, message)
+    err = "#{status} #{message}"
+    msg = <<-"MSGEND"
+      <html>
+        <head>
+          <title>#{err}</title>
+        </head>
+        <body>
+          <h1>#{err}</h1>
+          <p>Unexpected error occurred while processing XML-RPC request!</p>
+        </body>
+      </html>
+    MSGEND
+
+    [status, { "Content-Type" => "text/html" }, [msg]]
+  end
+
+end
+
+
 class WEBrickServlet < BasicServer; end # forward declaration
 
 # Implements a standalone XML-RPC server. The method XMLRPC::Server#serve is
diff --git a/test/test_rack_server.rb b/test/test_rack_server.rb
@@ -0,0 +1,91 @@
+# frozen_string_literal: true
+
+require "test/unit"
+require "rack/test"
+require "xmlrpc/server"
+require 'xmlrpc/create'
+require 'xmlrpc/parser'
+
+class TestRack < Test::Unit::TestCase
+  include Rack::Test::Methods
+
+  def app
+    s = XMLRPC::RackApplication.new
+
+    s.add_handler("test.add") do |a,b|
+      a + b
+    end
+
+    s.add_handler("test.div") do |a,b|
+      if b == 0
+        raise XMLRPC::FaultException.new(1, "division by zero")
+      else
+        a / b
+      end
+    end
+
+    s.set_default_handler do |name, *args|
+      raise XMLRPC::FaultException.new(-99, "Method #{name} missing" +
+            " or wrong number of parameters!")
+    end
+
+    s.add_introspection
+
+    s
+  end
+
+  def test_successful_call
+    assert_equal([true, 9],
+                 call("test.add", 4, 5))
+  end
+
+  def test_fault_exception
+    assert_equal([false, XMLRPC::FaultException.new(1, "division by zero")],
+                 call("test.div", 1, 0))
+  end
+
+  def test_introspection
+    assert_equal([true, methods = ["test.add", "test.div", "system.listMethods", "system.methodSignature", "system.methodHelp"]],
+                 call("system.listMethods"))
+  end
+
+  def test_missing_handler
+    assert_equal([false, XMLRPC::FaultException.new(-99, "Method test.nonexisting missing or wrong number of parameters!")],
+                 call("test.nonexisting"))
+  end
+
+  def test_wrong_number_of_arguments
+    assert_equal([false, XMLRPC::FaultException.new(-99, "Method test.add missing or wrong number of parameters!")],
+                 call("test.add", 1, 2, 3))
+  end
+
+  def test_multibyte_characters
+    assert_equal([true, "あいうえおかきくけこ"],
+                 call("test.add", "あいうえお", "かきくけこ"))
+  end
+
+  def test_method_not_allowed
+    get("/", "<stub />", "CONTENT_TYPE" => "text/xml")
+    assert(last_response.method_not_allowed?, "Expected HTTP status code 405, got #{last_response.status} instead")
+  end
+
+  def test_bad_content_type
+    post("/", "<stub />", "CONTENT_TYPE" => "text/plain")
+    assert(last_response.bad_request?, "Expected HTTP status code 400, got #{last_response.status} instead")
+  end
+
+  def test_empty_request
+    post("/", "", "CONTENT_TYPE" => "text/xml")
+    assert_equal(411, last_response.status, "Expected HTTP status code 411, got #{last_response.status} instead")
+  end
+
+  def call(methodname, *args)
+    create = XMLRPC::Create.new(XMLRPC::Config.default_writer.new)
+    parser = XMLRPC::Config.default_parser.new
+
+    request = create.methodCall(methodname, *args)
+    post("/", request, "CONTENT_TYPE" => "text/xml")
+    assert(last_response.ok?, "Expected HTTP status code 200, got #{last_response.status} instead")
+    parser.parseMethodResponse(last_response.body)
+  end
+end
