63 lines
1.9 KiB
Ruby
63 lines
1.9 KiB
Ruby
module RuboCop
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module Cop
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module Gitlab
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class ModuleWithInstanceVariables < RuboCop::Cop::Cop
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MSG = <<~EOL.freeze
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Do not use instance variables in a module. Please read this
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for the rationale behind it:
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https://docs.gitlab.com/ee/development/module_with_instance_variables.html
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EOL
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def on_module(node)
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check_method_definition(node)
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# Not sure why some module would have an extra begin wrapping around
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node.each_child_node(:begin) do |begin_node|
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check_method_definition(begin_node)
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end
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end
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private
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def check_method_definition(node)
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node.each_child_node(:def) do |definition|
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# We allow this pattern:
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#
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# def f
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# @f ||= true
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# end
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if only_ivar_or_assignment?(definition)
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# We don't allow if any other ivar is used
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definition.each_descendant(:ivar) do |offense|
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add_offense(offense, location: :expression)
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end
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# We allow initialize method and single ivar
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elsif !initialize_method?(definition) && !single_ivar?(definition)
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definition.each_descendant(:ivar, :ivasgn) do |offense|
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add_offense(offense, location: :expression)
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end
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end
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end
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end
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def only_ivar_or_assignment?(definition)
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node = definition.child_nodes.last
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definition.child_nodes.size == 2 &&
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node.or_asgn_type? && node.child_nodes.first.ivasgn_type?
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end
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def single_ivar?(definition)
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node = definition.child_nodes.last
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definition.child_nodes.size == 2 && node.ivar_type?
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end
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def initialize_method?(definition)
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definition.children.first == :initialize
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end
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end
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end
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end
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end
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