Module: Hitch::MCP::TestHelper

Defined in:
lib/hitch/mcp/test_helper.rb

Constant Summary collapse

PROTOCOL_VERSION =

Public: host test suites pin this.

Protocol::VERSION

Instance Method Summary collapse

Instance Method Details

#mcp_headers(token:, method:, name: nil, protocol_version: PROTOCOL_VERSION) ⇒ Object 



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# File 'lib/hitch/mcp/test_helper.rb', line 19

def mcp_headers(token:, method:, name: nil, protocol_version: PROTOCOL_VERSION)
  resource = mcp_test_resource_uri!
  mcp_test_headers(
    resource:,
    token:,
    method:,
    name:,
    protocol_version:
  )
end

#mint_mcp_token(principal:, scopes: Hitch.configuration.supported_scopes, client_id: "hitch-test-client") ⇒ Object

Mints a real access token through the production authorization-code path (create_authorization! + PKCE exchange) and returns the raw bearer token post_mcp expects. The principal is any persisted record the host treats as the signed-in user.



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# File 'lib/hitch/mcp/test_helper.rb', line 78

def mint_mcp_token(principal:, scopes: Hitch.configuration.supported_scopes,
  client_id: "hitch-test-client")
  scopes = Array(scopes)
  unsupported = scopes - Hitch.configuration.supported_scopes
  unless unsupported.empty?
    # The real flow clamps grants to supported_scopes; minting past it
    # would let a test pass against a grant production can never issue.
    raise ArgumentError,
      "scopes are not in Hitch.configuration.supported_scopes: #{unsupported.join(' ')}"
  end

  verifier = SecureRandom.urlsafe_base64(64)
  challenge = Base64.urlsafe_encode64(Digest::SHA256.digest(verifier), padding: false)
  resource_uri = Hitch.configuration.resource_uri
  authorization = Hitch::AccessToken.create_authorization!(
    principal: principal,
    client_id: client_id,
    client_name: client_id,
    code_challenge: challenge,
    code_challenge_method: "S256",
    scopes: scopes.join(" "),
    resource_uri: resource_uri
  )
  Hitch::AccessToken.exchange_authorization_code!(
    raw_code: authorization.raw_authorization_code,
    code_verifier: verifier,
    client_id: client_id,
    resource_uri: resource_uri
  ).fetch(:raw_token)
end

#post_mcp(method:, token:, params: {}, id: "hitch-test", client_info: nil, capabilities: {}, protocol_version: PROTOCOL_VERSION) ⇒ Object 



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# File 'lib/hitch/mcp/test_helper.rb', line 30

def post_mcp(method:, token:, params: {}, id: "hitch-test", client_info: nil,
  capabilities: {}, protocol_version: PROTOCOL_VERSION)
  resource = mcp_test_resource_uri!
  mcp_test_match_scheme!(resource)
  normalized_params = mcp_test_json_hash(params, "params")
  raise ArgumentError, "params must not supply _meta" if normalized_params.key?("_meta")

  normalized_capabilities = mcp_test_json_hash(capabilities, "capabilities")
  normalized_client_info = if client_info.nil?
    nil
  else
    mcp_test_json_hash(client_info, "client_info")
  end
  normalized_id = mcp_test_id(id)
  name = normalized_params["name"] if method == "tools/call"
  metadata = {
    "io.modelcontextprotocol/protocolVersion" => protocol_version.to_s,
    "io.modelcontextprotocol/clientCapabilities" => normalized_capabilities
  }
  if normalized_client_info
    metadata["io.modelcontextprotocol/clientInfo"] = normalized_client_info
  end
  normalized_params["_meta"] = metadata
  body = JSON.generate(
    "jsonrpc" => "2.0",
    "id" => normalized_id,
    "method" => method,
    "params" => normalized_params
  )

  post resource.request_uri,
    params: body,
    headers: mcp_test_headers(
      resource:,
      token:,
      method:,
      name:,
      protocol_version:
    )
  response
rescue JSON::GeneratorError, EncodingError => error
  raise ArgumentError, "MCP test request is not valid JSON: #{error.class}"
end