Class: RuboCop::Cop::Style::SignalException

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector
Includes:
ConfigurableEnforcedStyle
Defined in:
lib/rubocop/cop/style/signal_exception.rb

Overview

This cop checks for uses of `fail` and `raise`.

Examples:

EnforcedStyle: only_raise (default)

# The `only_raise` style enforces the sole use of `raise`.
# bad
begin
  fail
rescue Exception
  # handle it
end

def watch_out
  fail
rescue Exception
  # handle it
end

Kernel.fail

# good
begin
  raise
rescue Exception
  # handle it
end

def watch_out
  raise
rescue Exception
  # handle it
end

Kernel.raise

EnforcedStyle: only_fail

# The `only_fail` style enforces the sole use of `fail`.
# bad
begin
  raise
rescue Exception
  # handle it
end

def watch_out
  raise
rescue Exception
  # handle it
end

Kernel.raise

# good
begin
  fail
rescue Exception
  # handle it
end

def watch_out
  fail
rescue Exception
  # handle it
end

Kernel.fail

EnforcedStyle: semantic

# The `semantic` style enforces the use of `fail` to signal an
# exception, then will use `raise` to trigger an offense after
# it has been rescued.
# bad
begin
  raise
rescue Exception
  # handle it
end

def watch_out
  # Error thrown
rescue Exception
  fail
end

Kernel.fail
Kernel.raise

# good
begin
  fail
rescue Exception
  # handle it
end

def watch_out
  fail
rescue Exception
  raise 'Preferably with descriptive message'
end

explicit_receiver.fail
explicit_receiver.raise

Constant Summary collapse

FAIL_MSG =
'Use `fail` instead of `raise` to signal exceptions.'
RAISE_MSG =
'Use `raise` instead of `fail` to rethrow exceptions.'
RESTRICT_ON_SEND =
%i[raise fail].freeze

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Methods included from ConfigurableEnforcedStyle

#alternative_style, #alternative_styles, #ambiguous_style_detected, #correct_style_detected, #detected_style, #detected_style=, #no_acceptable_style!, #no_acceptable_style?, #opposite_style_detected, #style, #style_configured?, #style_detected, #style_parameter_name, #supported_styles, #unexpected_style_detected

Methods inherited from Base

#add_global_offense, #add_offense, autocorrect_incompatible_with, badge, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, #cop_name, cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, joining_forces, lint?, match?, #offenses, #on_investigation_end, #on_other_file, #parse, #ready, #relevant_file?, support_autocorrect?, support_multiple_source?, #target_rails_version, #target_ruby_version

Methods included from ExcludeLimit

#exclude_limit

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #correctable?, #disable_uncorrectable?, #safe_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

silence_warnings

Constructor Details

This class inherits a constructor from RuboCop::Cop::Base

Instance Method Details

#custom_fail_methods(node) ⇒ Object


120
# File 'lib/rubocop/cop/style/signal_exception.rb', line 120

def_node_search :custom_fail_methods, '{(def :fail ...) (defs _ :fail ...)}'

#kernel_call?(node, name) ⇒ Object


117
# File 'lib/rubocop/cop/style/signal_exception.rb', line 117

def_node_matcher :kernel_call?, '(send (const {nil? cbase} :Kernel) %1 ...)'

#on_new_investigationObject


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# File 'lib/rubocop/cop/style/signal_exception.rb', line 122

def on_new_investigation
  ast = processed_source.ast
  @custom_fail_defined = ast && custom_fail_methods(ast).any?
end

#on_rescue(node) ⇒ Object


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# File 'lib/rubocop/cop/style/signal_exception.rb', line 127

def on_rescue(node)
  return unless style == :semantic

  begin_node, *rescue_nodes, _else_node = *node
  check_scope(:raise, begin_node)

  rescue_nodes.each do |rescue_node|
    check_scope(:fail, rescue_node)
    allow(:raise, rescue_node)
  end
end

#on_send(node) ⇒ Object


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# File 'lib/rubocop/cop/style/signal_exception.rb', line 139

def on_send(node)
  case style
  when :semantic
    check_send(:raise, node) unless ignored_node?(node)
  when :only_raise
    return if @custom_fail_defined

    check_send(:fail, node)
  when :only_fail
    check_send(:raise, node)
  end
end