modelcontextprotocol/ruby-sdk
Watch
1
0
Fork
You've already forked ruby-sdk
 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Support Ruby 2.7 - Ruby 3.1

Browse source 
## Summary

Unlike applications, libraries provide value by remaining usable for a broad range of users,
even when that means supporting older Ruby versions beyond Ruby's own EOL timeline.

I maintain RuboCop, a Ruby linter. Because linters need to work across the ecosystem,
they often need to keep compatibility with older Ruby versions to some extent.

The trade-off is that the MCP Ruby SDK must remain compatible with Ruby 2.7.
However, given the ecosystem impact, supporting Ruby 2.7 is still worthwhile.

For example, bundled gems such as `csv` (Ruby >= 2.5), `bigdecimal` (Ruby >= 2.5), `json` (Ruby >= 2.7),
and `language_server-protocol` (Ruby >= 2.5) tend to keep compatibility with older Ruby versions.

Unlike dropping support, which imposes restrictions on users,
this change broadens compatibility and does not introduce breaking changes.

## Development Note

`rubocop-shopify` (2.18) supports Ruby 3.1+, and this PR does not change that.
Since RuboCop can configure the runtime Ruby version and the target Ruby version for analysis independently,
CI continues to run RuboCop on Ruby 4.0, while analyzing code with `TargetRubyVersion: 2.7`.

When setting `TargetRubyVersion: 2.7`, several RuboCop offenses were resolved.

Additionally, Sorbet-related libraries support Ruby 3.0+. Since these are not dependencies of the MCP Ruby SDK itself,
they are versioned and tested in the development Gemfile.
This commit is contained in:
Koichi ITO 2025-12-21 23:21:19 +09:00
commit aa8bbad491
7 changed files with 106 additions and 100 deletions
Download patch file Download diff file Expand all files Collapse all files

8
test/json_rpc_handler_test.rb
View file

@ -94,7 +94,7 @@ describe JsonRpcHandler do
register("add") { |params| params[:a] + params[:b] }
id = "request-123_abc"
handle jsonrpc: "2.0", id:, method: "add", params: { a: 1, b: 2 }
handle jsonrpc: "2.0", id: id, method: "add", params: { a: 1, b: 2 }
assert_rpc_success expected_result: 3
assert_equal id, @response[:id]
@ -104,7 +104,7 @@ describe JsonRpcHandler do
register("add") { |params| params[:a] + params[:b] }
id = 42
handle jsonrpc: "2.0", id:, method: "add", params: { a: 1, b: 2 }
handle jsonrpc: "2.0", id: id, method: "add", params: { a: 1, b: 2 }
assert_rpc_success expected_result: 3
assert_equal id, @response[:id]
@ -124,7 +124,7 @@ describe JsonRpcHandler do
register("add") { |params| params[:a] + params[:b] }
id = "request-123_ABC"
handle jsonrpc: "2.0", id:, method: "add", params: { a: 1, b: 2 }
handle jsonrpc: "2.0", id: id, method: "add", params: { a: 1, b: 2 }
assert_rpc_success expected_result: 3
assert_equal id, @response[:id]
@ -134,7 +134,7 @@ describe JsonRpcHandler do
register("add") { |params| params[:a] + params[:b] }
id = "550e8400-e29b-41d4-a716-446655440000"
handle jsonrpc: "2.0", id:, method: "add", params: { a: 1, b: 2 }
handle jsonrpc: "2.0", id: id, method: "add", params: { a: 1, b: 2 }
assert_rpc_success expected_result: 3
assert_equal id, @response[:id]

46
test/mcp/client_test.rb
View file

@ -18,7 +18,7 @@ module MCP
# Only checking for the essential parts of the request
transport.expects(:send_request).with do |args|
args in { request: { method: "tools/list", jsonrpc: "2.0" } }
args.dig(:request, :method) == "tools/list" && args.dig(:request, :jsonrpc) == "2.0"
end.returns(mock_response).once
client = Client.new(transport: transport)
@ -35,7 +35,7 @@ module MCP
# Only checking for the essential parts of the request
transport.expects(:send_request).with do |args|
args in { request: { method: "tools/list", jsonrpc: "2.0" } }
args.dig(:request, :method) == "tools/list" && args.dig(:request, :jsonrpc) == "2.0"
end.returns(mock_response).once
client = Client.new(transport: transport)
@ -54,16 +54,10 @@ module MCP
# Only checking for the essential parts of the request
transport.expects(:send_request).with do |args|
args in {
request: {
method: "tools/call",
jsonrpc: "2.0",
params: {
name: "tool1",
arguments: arguments,
},
},
}
args.dig(:request, :method) == "tools/call" &&
args.dig(:request, :jsonrpc) == "2.0" &&
args.dig(:request, :params, :name) == "tool1" &&
args.dig(:request, :params, :arguments) == arguments
end.returns(mock_response).once
client = Client.new(transport: transport)
@ -86,7 +80,7 @@ module MCP
# Only checking for the essential parts of the request
transport.expects(:send_request).with do |args|
args in { request: { method: "resources/list", jsonrpc: "2.0" } }
args.dig(:request, :method) == "resources/list" && args.dig(:request, :jsonrpc) == "2.0"
end.returns(mock_response).once
client = Client.new(transport: transport)
@ -124,15 +118,9 @@ module MCP
# Only checking for the essential parts of the request
transport.expects(:send_request).with do |args|
args in {
request: {
method: "resources/read",
jsonrpc: "2.0",
params: {
uri: uri,
},
},
}
args.dig(:request, :method) == "resources/read" &&
args.dig(:request, :jsonrpc) == "2.0" &&
args.dig(:request, :params, :uri) == uri
end.returns(mock_response).once
client = Client.new(transport: transport)
@ -190,7 +178,7 @@ module MCP
# Only checking for the essential parts of the request
transport.expects(:send_request).with do |args|
args in { request: { method: "prompts/list", jsonrpc: "2.0" } }
args.dig(:request, :method) == "prompts/list" && args.dig(:request, :jsonrpc) == "2.0"
end.returns(mock_response).once
client = Client.new(transport: transport)
@ -242,15 +230,9 @@ module MCP
# Only checking for the essential parts of the request
transport.expects(:send_request).with do |args|
args in {
request: {
method: "prompts/get",
jsonrpc: "2.0",
params: {
name: name,
},
},
}
args.dig(:request, :method) == "prompts/get" &&
args.dig(:request, :jsonrpc) == "2.0" &&
args.dig(:request, :params, :name) == name
end.returns(mock_response).once
client = Client.new(transport: transport)

2
test/mcp/prompt_test.rb
View file

@ -132,7 +132,7 @@ module MCP
description: "Hello, world!",
messages: [
Prompt::Message.new(role: "user", content: Content::Text.new("Hello, world!")),
Prompt::Message.new(role: "assistant", content:),
Prompt::Message.new(role: "assistant", content: content),
],
)
end

8
test/mcp/server/transports/streamable_http_transport_test.rb
View file

@ -388,7 +388,7 @@ module MCP
@server.define_singleton_method(:handle_json) do |request|
result = original_handle_json.call(request)
# Send notification while still in request context - broadcast to all sessions
transport.send_notification("test_notification", { session: "current" })
transport.send_notification("test_notification", { session: "current" }, **{})
result
end
@ -500,7 +500,7 @@ module MCP
sleep(0.1)
# Broadcast notification to all sessions
sent_count = @transport.send_notification("broadcast", { message: "Hello everyone" })
sent_count = @transport.send_notification("broadcast", { message: "Hello everyone" }, **{})
assert_equal 2, sent_count
@ -517,7 +517,7 @@ module MCP
end
test "send_notification returns false for non-existent session" do
result = @transport.send_notification({ message: "test" }, session_id: "non_existent")
result = @transport.send_notification("test", { message: "test" }, session_id: "non_existent")
refute result
end
@ -549,7 +549,7 @@ module MCP
io.close
# Try to send notification
result = @transport.send_notification({ message: "test" }, session_id: session_id)
result = @transport.send_notification("test", { message: "test" }, session_id: session_id)
# Should return false and clean up the session
refute result

26
test/mcp/server_test.rb
View file

@ -80,7 +80,7 @@ module MCP
prompts: [@prompt],
resources: [@resource],
resource_templates: [@resource_template],
configuration:,
configuration: configuration,
)
end
@ -244,7 +244,13 @@ module MCP
tool_args = { arg: "value" }
tool_response = Tool::Response.new([{ result: "success" }])
@tool.expects(:call).with(arg: "value", server_context: nil).returns(tool_response)
if RUBY_VERSION >= "3.1"
# Ruby 3.1+: Mocha stub preserves `method.parameters` info.
@tool.expects(:call).with(arg: "value", server_context: nil).returns(tool_response)
else
# Ruby 3.0: Mocha stub changes `method.parameters`, so `accepts_server_context?` returns false.
@tool.expects(:call).with(arg: "value").returns(tool_response)
end
request = {
jsonrpc: "2.0",
@ -258,7 +264,7 @@ module MCP
response = @server.handle(request)
assert_equal tool_response.to_h, response[:result]
assert_instrumentation_data({ method: "tools/call", tool_name: })
assert_instrumentation_data({ method: "tools/call", tool_name: tool_name })
end
test "#handle tools/call returns error response with isError true if required tool arguments are missing" do
@ -296,7 +302,13 @@ module MCP
tool_args = { arg: "value" }
tool_response = Tool::Response.new([{ result: "success" }])
@tool.expects(:call).with(arg: "value", server_context: nil).returns(tool_response)
if RUBY_VERSION >= "3.1"
# Ruby 3.1+: Mocha stub preserves `method.parameters` info.
@tool.expects(:call).with(arg: "value", server_context: nil).returns(tool_response)
else
# Ruby 3.0: Mocha stub changes `method.parameters`, so `accepts_server_context?` returns false.
@tool.expects(:call).with(arg: "value").returns(tool_response)
end
request = JSON.generate({
jsonrpc: "2.0",
@ -308,10 +320,12 @@ module MCP
raw_response = @server.handle_json(request)
response = JSON.parse(raw_response, symbolize_names: true) if raw_response
assert_equal tool_response.to_h, response[:result] if response
assert_instrumentation_data({ method: "tools/call", tool_name: })
assert_instrumentation_data({ method: "tools/call", tool_name: tool_name })
end
test "#handle_json tools/call executes tool and returns result, when the tool is typed with Sorbet" do
skip "Sorbet is not available" unless defined?(T::Sig)
class TypedTestTool < Tool
tool_name "test_tool"
description "a test tool for testing"
@ -836,7 +850,7 @@ module MCP
configuration.instrumentation_callback = local_callback
configuration.exception_reporter = local_exception_reporter
server = Server.new(name: "test_server", configuration:)
server = Server.new(name: "test_server", configuration: configuration)
assert_equal local_callback, server.configuration.instrumentation_callback
assert_equal local_exception_reporter, server.configuration.exception_reporter

2
test/mcp/tool_test.rb
View file

@ -243,6 +243,8 @@ module MCP
end
test "#call with Sorbet typed tools invokes the tool block and returns the response" do
skip "sorbet-static-and-runtime requires Ruby 3.0+." if RUBY_VERSION < "3.0"
class TypedTestTool < Tool
tool_name "test_tool"
description "a test tool for testing"

2
test/test_helper.rb
View file

@ -9,6 +9,6 @@ require "mocha/minitest"
require "active_support"
require "active_support/test_case"
require "sorbet-runtime"
require "sorbet-runtime" if RUBY_VERSION >= "3.0"
require_relative "instrumentation_test_helper"