%script
click -e "
i :: Idle
rw :: IPAddrRewriter(pattern 1.0.0.1 - 0 1,
  pattern 1.0.0.1-1.0.255.255 - 0 1,
  pattern 1.0.0.1/24 - 0 1,
  pattern 1.0.0.1/8 - 0 1)
i -> [0]rw i[1] -> [1]rw i[2] -> [2]rw i[3] -> [3]rw
rw[0] -> i rw[1] -> i
" -h rw.patterns -q

click -e "
i :: Idle
rw :: IPAddrRewriter(pattern 1.0.0.x - 0 1,
  pattern 1.255.0.0-1.0.255.255 - 0 1)
i -> [0]rw i[1] -> [1]rw
rw[0] -> i rw[1] -> i
" 2>X || true

%expect stdout
1.0.0.1 - [0]
1.0.0.1-1.0.255.255 - [0]
1.0.0.1-1.0.0.254 - [0]
1.0.0.1-1.255.255.254 - [0]

%expect X
  input spec 0: bad source address
  input spec 1: bad source address
Router could not be initialized!

%ignore X
<expr.*