Module: JsonRpcHandler

Defined in:
lib/json_rpc_handler.rb,
lib/json_rpc_handler/version.rb

Defined Under Namespace

Classes: ErrorCode, Version

Constant Summary collapse

VERSION = 
'0.1.0'

Class Method Summary collapse

Class Method Details

.error_response(id:, error:) ⇒ Object 



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# File 'lib/json_rpc_handler.rb', line 137

def error_response(id:, error:)
  {
    jsonrpc: Version::V2_0,
    id: valid_id?(id) ? id : nil,
    error: error.compact,
  } unless id.nil?
end

.handle(request, &method_finder) ⇒ Object 



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# File 'lib/json_rpc_handler.rb', line 21

def handle(request, &method_finder)
  if request.is_a? Array
    return error_response id: :unknown_id, error: {
      code: ErrorCode::InvalidRequest,
      message: 'Invalid Request',
      data: 'Request is an empty array',
    } if request.empty?

    # Handle batch requests
    responses = request.map { |req| process_request req, &method_finder }.compact

    # A single item is hoisted out of the array
    return responses.first if responses.one?

    # An empty array yields nil
    responses if responses.any?
  elsif request.is_a? Hash
    # Handle single request
    process_request request, &method_finder
  else
    error_response id: :unknown_id, error: {
      code: ErrorCode::InvalidRequest,
      message: 'Invalid Request',
      data: 'Request must be an array or a hash',
    }
  end
end

.handle_json(request_json, &method_finder) ⇒ Object 



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# File 'lib/json_rpc_handler.rb', line 49

def handle_json(request_json, &method_finder)
  begin
    request = JSON.parse request_json, symbolize_names: true
    response = handle request, &method_finder
  rescue JSON::ParserError
    response =error_response id: :unknown_id, error: {
      code: ErrorCode::ParseError,
      message: 'Parse error',
      data: 'Invalid JSON',
    }
  end

  response.to_json if response
end

.process_request(request, &method_finder) ⇒ Object 



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# File 'lib/json_rpc_handler.rb', line 64

def process_request(request, &method_finder)
  id = request[:id]

  error = case
    when !valid_version?(request[:jsonrpc]) then 'JSON-RPC version must be 2.0'
    when !valid_id?(request[:id]) then 'Request ID must be a string or an integer or null'
    when !valid_method_name?(request[:method]) then 'Method name must be a string and not start with "rpc."'
  end

  return error_response id: :unknown_id, error: {
    code: ErrorCode::InvalidRequest,
    message: 'Invalid Request',
    data: error,
  } if error

  method_name = request[:method]
  params = request[:params]

  unless valid_params? params
    return error_response id:, error: {
      code: ErrorCode::InvalidParams,
      message: 'Invalid params',
      data: 'Method parameters must be an array or an object or null',
    }
  end

  begin
    method = method_finder.call method_name

    if method.nil?
      return error_response id:, error: {
        code: ErrorCode::MethodNotFound,
        message: 'Method not found',
        data: method_name,
      }
    end

    result = method.call params

    success_response id:, result:
  rescue StandardError => e
    error_response id:, error: {
      code: ErrorCode::InternalError,
      message: 'Internal error',
      data: e.message,
    }
  end
end

.success_response(id:, result:) ⇒ Object 



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# File 'lib/json_rpc_handler.rb', line 129

def success_response(id:, result:)
  {
    jsonrpc: Version::V2_0,
    id:,
    result:,
  } unless id.nil?
end

.valid_id?(id) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/json_rpc_handler.rb', line 117

def valid_id?(id)
  id.is_a?(String) || id.is_a?(Integer) || id.nil?
end

.valid_method_name?(method) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/json_rpc_handler.rb', line 121

def valid_method_name?(method)
  method.is_a?(String) && !method.start_with?('rpc.')
end

.valid_params?(params) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/json_rpc_handler.rb', line 125

def valid_params?(params)
  params.nil? || params.is_a?(Array) || params.is_a?(Hash)
end

.valid_version?(version) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/json_rpc_handler.rb', line 113

def valid_version?(version)
  version == Version::V2_0
end