class RuboCop::Cop::Rails::Blank
This cop checks for code that can be written with simpler conditionals using `Object#blank?` defined by Active Support.
This cop is marked as unsafe auto-correction, because `' '.empty?` returns false, but `' '.blank?` returns true. Therefore, auto-correction is not compatible if the receiver is a non-empty blank string, tab, or newline meta characters.
Interaction with `Style/UnlessElse`: The configuration of `NotPresent` will not produce an offense in the context of `unless else` if `Style/UnlessElse` is inabled. This is to prevent interference between the auto-correction of the two cops.
@example NilOrEmpty: true (default)
# Converts usages of `nil? || empty?` to `blank?` # bad foo.nil? || foo.empty? foo == nil || foo.empty? # good foo.blank?
@example NotPresent: true (default)
# Converts usages of `!present?` to `blank?` # bad !foo.present? # good foo.blank?
@example UnlessPresent: true (default)
# Converts usages of `unless present?` to `if blank?` # bad something unless foo.present? # good something if foo.blank? # bad unless foo.present? something end # good if foo.blank? something end # good def blank? !present? end
Constants
- MSG_NIL_OR_EMPTY
- MSG_NOT_PRESENT
- MSG_UNLESS_PRESENT
- RESTRICT_ON_SEND
Public Instance Methods
on_if(node)
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# File lib/rubocop/cop/rails/blank.rb, line 123 def on_if(node) return unless cop_config['UnlessPresent'] return unless node.unless? return if node.else? && config.for_cop('Style/UnlessElse')['Enabled'] unless_present?(node) do |method_call, receiver| range = unless_condition(node, method_call) message = format(MSG_UNLESS_PRESENT, prefer: replacement(receiver), current: range.source) add_offense(range, message: message) do |corrector| autocorrect(corrector, node) end end end
on_or(node)
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# File lib/rubocop/cop/rails/blank.rb, line 110 def on_or(node) return unless cop_config['NilOrEmpty'] nil_or_empty?(node) do |var1, var2| return unless var1 == var2 message = format(MSG_NIL_OR_EMPTY, prefer: replacement(var1), current: node.source) add_offense(node, message: message) do |corrector| autocorrect(corrector, node) end end end
on_send(node)
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# File lib/rubocop/cop/rails/blank.rb, line 96 def on_send(node) return unless cop_config['NotPresent'] not_present?(node) do |receiver| # accepts !present? if its in the body of a `blank?` method next if defining_blank?(node.parent) message = format(MSG_NOT_PRESENT, prefer: replacement(receiver), current: node.source) add_offense(node, message: message) do |corrector| autocorrect(corrector, node) end end end
Private Instance Methods
autocorrect(corrector, node)
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# File lib/rubocop/cop/rails/blank.rb, line 140 def autocorrect(corrector, node) method_call, variable1 = unless_present?(node) if method_call corrector.replace(node.loc.keyword, 'if') range = method_call.loc.expression else variable1, _variable2 = nil_or_empty?(node) || not_present?(node) range = node.loc.expression end corrector.replace(range, replacement(variable1)) end
replacement(node)
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# File lib/rubocop/cop/rails/blank.rb, line 162 def replacement(node) node.respond_to?(:source) ? "#{node.source}.blank?" : 'blank?' end
unless_condition(node, method_call)
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# File lib/rubocop/cop/rails/blank.rb, line 154 def unless_condition(node, method_call) if node.modifier_form? node.loc.keyword.join(node.loc.expression.end) else node.loc.expression.begin.join(method_call.loc.expression) end end