Method: Pbt::Arbitrary::ArrayArbitrary#shrink

Defined in:
lib/pbt/arbitrary/array_arbitrary.rb

#shrink(current) ⇒ Object

See Also:


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# File 'lib/pbt/arbitrary/array_arbitrary.rb', line 29

def shrink(current)
  return Enumerator.new { |_| } if current.size == @min_length

  Enumerator.new do |y|
    # First, shrink the length of the array and try combinations of elements.
    # But this doesn't try all possible combinations since it'd be too huge and slow.
    @length_arb.shrink(current.size).each do |length|
      if length == 0
        y.yield []
        next
      end
      current.each_cons(length) do |con|
        y.yield con
      end
    end

    # Second, shrink each element of the array.
    current.each_with_index do |item, i|
      @value_arb.shrink(item).each do |val|
        y.yield [*current[...i], val, *current[i + 1..]]
      end
    end
  end
end