free_mutant/lib/mutant/mutator/node/case.rb
Dan Kubb d3470d08cb Fix mutation with one when clause in a case statement
* When there was only one when clause, one mutation would remove
  it which would cause the case statement to become invalid.
2013-06-22 23:00:40 -07:00

60 lines
1.2 KiB
Ruby

module Mutant
class Mutator
class Node
# Mutator for case nodes
class Case < self
handle(:case)
children :condition
private
# Emit mutations
#
# @return [undefined]
#
# @api private
#
def dispatch
emit_condition_mutations
emit_branch_mutations
end
# Emit presence mutations
#
# @return [undefined]
#
# @api private
#
def emit_branch_mutations
remaining_children_with_index.each do |child, index|
next unless child
mutate_index(index)
end
end
# Perform mutations of child index
#
# @param [Fixnum] index
#
# @return [undefined]
#
# @api private
#
def mutate_index(index)
mutate_child(index)
dup_children = children.dup
dup_children.delete_at(index)
return if dup_children.none? { |child| child.type == :when }
if dup_children.last.type == :when
dup_children << nil
end
emit_self(*dup_children)
end
end # Case
end # Node
end # Mutator
end # Mutant