class RuboCop::Cop::Lint::Void
This cop checks for operators, variables, literals, and nonmutating methods used in void context.
@example
# bad def some_method some_num * 10 do_something end
@example
# bad def some_method(some_var) some_var do_something end
@example
# bad, when CheckForMethodsWithNoSideEffects is set true def some_method(some_array) some_array.sort do_something(some_array) end
@example
# good def some_method do_something some_num * 10 end
@example
# good def some_method(some_var) do_something some_var end
@example
# good, when CheckForMethodsWithNoSideEffects is set true def some_method(some_array) some_array.sort! do_something(some_array) end
Constants
- BINARY_OPERATORS
- DEFINED_MSG
- LIT_MSG
- NONMUTATING_METHODS
- NONMUTATING_MSG
- OPERATORS
- OP_MSG
- SELF_MSG
- UNARY_OPERATORS
- VAR_MSG
- VOID_CONTEXT_TYPES
Public Instance Methods
on_begin(node)
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# File lib/rubocop/cop/lint/void.rb, line 90 def on_begin(node) check_begin(node) end
Also aliased as: on_kwbegin
on_block(node)
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# File lib/rubocop/cop/lint/void.rb, line 83 def on_block(node) return unless node.body && !node.body.begin_type? return unless in_void_context?(node.body) check_expression(node.body) end
Private Instance Methods
check_begin(node)
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# File lib/rubocop/cop/lint/void.rb, line 97 def check_begin(node) expressions = *node expressions.pop unless in_void_context?(node) expressions.each do |expr| check_expression(expr) end end
check_defined(node)
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# File lib/rubocop/cop/lint/void.rb, line 144 def check_defined(node) return unless node.defined_type? add_offense(node, message: format(DEFINED_MSG, defined: node.source)) end
check_expression(expr)
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# File lib/rubocop/cop/lint/void.rb, line 105 def check_expression(expr) check_void_op(expr) check_literal(expr) check_var(expr) check_self(expr) check_defined(expr) return unless cop_config['CheckForMethodsWithNoSideEffects'] check_nonmutating(expr) end
check_literal(node)
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# File lib/rubocop/cop/lint/void.rb, line 132 def check_literal(node) return if !node.literal? || node.xstr_type? add_offense(node, message: format(LIT_MSG, lit: node.source)) end
check_nonmutating(node)
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# File lib/rubocop/cop/lint/void.rb, line 150 def check_nonmutating(node) unless node.send_type? && NONMUTATING_METHODS.include?(node.method_name) return end add_offense(node, message: format(NONMUTATING_MSG, method: node.method_name)) end
check_self(node)
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# File lib/rubocop/cop/lint/void.rb, line 138 def check_self(node) return unless node.self_type? add_offense(node, message: SELF_MSG) end
check_var(node)
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# File lib/rubocop/cop/lint/void.rb, line 124 def check_var(node) return unless node.variable? || node.const_type? add_offense(node, location: :name, message: format(VAR_MSG, var: node.loc.name.source)) end
check_void_op(node)
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# File lib/rubocop/cop/lint/void.rb, line 116 def check_void_op(node) return unless node.send_type? && OPERATORS.include?(node.method_name) add_offense(node, location: :selector, message: format(OP_MSG, op: node.method_name)) end
in_void_context?(node)
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# File lib/rubocop/cop/lint/void.rb, line 160 def in_void_context?(node) parent = node.parent return false unless parent && parent.children.last == node VOID_CONTEXT_TYPES.include?(parent.type) && parent.void_context? end