class RuboCop::Cop::Style::RescueModifier
Checks for uses of rescue in its modifier form.
The cop to check `rescue` in its modifier form is added for following reasons:
-
The syntax of modifier form `rescue` can be misleading because it might lead us to believe that `rescue` handles the given exception but it actually rescue all exceptions to return the given rescue block. In this case, value returned by handle_error or SomeException.
-
Modifier form `rescue` would rescue all the exceptions. It would silently skip all exception or errors and handle the error. Example: If `NoMethodError` is raised, modifier form rescue would handle the exception.
@example
# bad some_method rescue handle_error # bad some_method rescue SomeException # good begin some_method rescue handle_error end # good begin some_method rescue SomeException handle_error end
Constants
- MSG
Public Class Methods
autocorrect_incompatible_with()
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# File lib/rubocop/cop/style/rescue_modifier.rb, line 50 def self.autocorrect_incompatible_with [Style::MethodCallWithArgsParentheses] end
Public Instance Methods
on_resbody(node)
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# File lib/rubocop/cop/style/rescue_modifier.rb, line 54 def on_resbody(node) return unless rescue_modifier?(node) rescue_node = node.parent add_offense(rescue_node) do |corrector| parenthesized = parenthesized?(rescue_node) correct_rescue_block(corrector, rescue_node, parenthesized) ParenthesesCorrector.correct(corrector, rescue_node.parent) if parenthesized end end
Private Instance Methods
correct_rescue_block(corrector, node, parenthesized)
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# File lib/rubocop/cop/style/rescue_modifier.rb, line 72 def correct_rescue_block(corrector, node, parenthesized) operation, rescue_modifier, = *node *_, rescue_args = *rescue_modifier node_indentation, node_offset = indentation_and_offset(node, parenthesized) corrector.remove(range_between(operation.source_range.end_pos, node.source_range.end_pos)) corrector.insert_before(operation, "begin\n#{node_indentation}") corrector.insert_after(operation, <<~RESCUE_CLAUSE.chop) #{node_offset}rescue #{node_indentation}#{rescue_args.source} #{node_offset}end RESCUE_CLAUSE end
indentation_and_offset(node, parenthesized)
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# File lib/rubocop/cop/style/rescue_modifier.rb, line 88 def indentation_and_offset(node, parenthesized) node_indentation = indentation(node) node_offset = offset(node) if parenthesized node_indentation = node_indentation[0...-1] node_offset = node_offset[0...-1] end [node_indentation, node_offset] end
parenthesized?(node)
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# File lib/rubocop/cop/style/rescue_modifier.rb, line 68 def parenthesized?(node) node.parent && parentheses?(node.parent) end