# frozen_string_literal: true
module ConvenientService
module Service
module Plugins
module RescuesResultUnhandledExceptions
module Commands
class FormatException < Support::Command
##
# @!attribute [r] exception
# @return [StandardError]
#
attr_reader :exception
##
# @!attribute [r] args
# @return [StandardError]
#
attr_reader :args
##
# @!attribute [r] kwargs
# @return [StandardError]
#
attr_reader :kwargs
##
# @!attribute [r] block
# @return [StandardError]
#
attr_reader :block
##
# @param exception [StandardError]
# @param args [Array]
# @param kwargs [Hash]
# @param block [Proc, nil]
# @return [void]
#
def initialize(exception:, args:, kwargs:, block:)
@exception = exception
@args = args
@kwargs = kwargs
@block = block
end
##
# @return [String]
#
# @note Exceptions formatting is inspired by RSpec. It has almost the same output (at least for RSpec 3).
#
# @example Simple exception.
#
# StandardError:
# exception message
# # /gem/lib/convenient_service/factories/services.rb:120:in `result'
# # /gem/lib/convenient_service/core/entities/config/entities/method_middlewares/entities/caller/commands/define_method_middlewares_caller.rb:116:in `call'
# # /gem/lib/convenient_service/core/entities/config/entities/method_middlewares/entities/caller/commands/define_method_middlewares_caller.rb:116:in `block in result'
# # /gem/lib/convenient_service/dependencies/extractions/ruby_middleware/middleware/runner.rb:67:in `block (2 levels) in build_call_chain'
# # /gem/lib/convenient_service/core/entities/config/entities/method_middlewares/entities/chain.rb:35:in `next'
# # /gem/lib/convenient_service/common/plugins/caches_return_value/middleware.rb:17:in `block in next'
# # /gem/lib/convenient_service/support/cache.rb:110:in `fetch'
# # /gem/lib/convenient_service/common/plugins/caches_return_value/middleware.rb:17:in `next'
# # /gem/lib/convenient_service/core/entities/config/entities/method_middlewares/entities/middleware.rb:73:in `call'
# # /gem/lib/convenient_service/core/entities/config/entities/method_middlewares/entities/chain.rb:35:in `next'
#
# @example Exception with backtrace with more than 10 lines.
#
# StandardError:
# exception message
# # /gem/lib/convenient_service/factories/services.rb:120:in `result'
# # /gem/lib/convenient_service/core/entities/config/entities/method_middlewares/entities/caller/commands/define_method_middlewares_caller.rb:116:in `call'
# # /gem/lib/convenient_service/core/entities/config/entities/method_middlewares/entities/caller/commands/define_method_middlewares_caller.rb:116:in `block in result'
# # /gem/lib/convenient_service/dependencies/extractions/ruby_middleware/middleware/runner.rb:67:in `block (2 levels) in build_call_chain'
# # /gem/lib/convenient_service/core/entities/config/entities/method_middlewares/entities/chain.rb:35:in `next'
# # /gem/lib/convenient_service/common/plugins/caches_return_value/middleware.rb:17:in `block in next'
# # /gem/lib/convenient_service/support/cache.rb:110:in `fetch'
# # /gem/lib/convenient_service/common/plugins/caches_return_value/middleware.rb:17:in `next'
# # /gem/lib/convenient_service/core/entities/config/entities/method_middlewares/entities/middleware.rb:73:in `call'
# # /gem/lib/convenient_service/core/entities/config/entities/method_middlewares/entities/chain.rb:35:in `next'
# # ...
#
# @example Exception with cause.
#
# StandardError:
# exception message
# # /gem/lib/convenient_service/factories/service/class.rb:43:in `rescue in result'
# # /gem/lib/convenient_service/factories/service/class.rb:40:in `result'
# # /gem/lib/convenient_service/core/entities/config/entities/method_middlewares/entities/caller/commands/define_method_middlewares_caller.rb:116:in `call'
# # /gem/lib/convenient_service/core/entities/config/entities/method_middlewares/entities/caller/commands/define_method_middlewares_caller.rb:116:in `block in result'
# # /gem/lib/convenient_service/dependencies/extractions/ruby_middleware/middleware/runner.rb:67:in `block (2 levels) in build_call_chain'
# # /gem/lib/convenient_service/core/entities/config/entities/method_middlewares/entities/chain.rb:35:in `next'
# # /gem/lib/convenient_service/common/plugins/caches_return_value/middleware.rb:17:in `block in next'
# # /gem/lib/convenient_service/support/cache.rb:110:in `fetch'
# # /gem/lib/convenient_service/common/plugins/caches_return_value/middleware.rb:17:in `next'
# # /gem/lib/convenient_service/core/entities/config/entities/method_middlewares/entities/middleware.rb:73:in `call'
# ------------------
# --- Caused by: ---
# StandardError:
# cause message
# # /gem/lib/convenient_service/factories/service/class.rb:41:in `result'
#
# @internal
# TODO: Think about the following questions:
# - How to format args, kwargs and block?
# - Who should format them? The end-user or this plugin?
#
def call
<<~MESSAGE.rstrip
#{formatted_exception}
#{formatted_exception_backtrace}
#{formatted_exception_cause}
MESSAGE
end
private
##
# @return [String]
#
def formatted_exception
<<~MESSAGE.chomp
#{exception.class}:
#{exception.message}
MESSAGE
end
##
# Formats exception backtrace. When backtrace has more then `max_backtrace_size` lines, the extra lines are trimmed.
# That is especially important for the monitoring system with the limited amount of memory, since it may too expensive to store the full backtrace all the time.
#
# @return [String]
#
# @internal
# TODO: Add an ability to set `max_backtrace_size` while configuring the middleware. For example:
#
# class Service
# include ConvenientService::Standard::Config
#
# middlewares :result, scope: :class do
# use ConvenientService::Service::Plugins::RescuesResultUnhandledExceptions::Middleware, max_backtrace_size: 1_000
# end
#
# # ...
# end
#
def formatted_exception_backtrace
Commands::FormatBacktrace.call(backtrace: exception.backtrace, max_size: max_backtrace_size)
end
##
# @return [String]
#
def formatted_exception_cause
Commands::FormatCause.call(cause: exception.cause)
end
##
# @return [Integer]
#
def max_backtrace_size
Constants::DEFAULT_MAX_BACKTRACE_SIZE
end
end
end
end
end
end
end