$ node test_weak.js .
PASS small order: shippingCost(20) = 6.95, expected 6.95
PASS large order: shippingCost(250) = 0, expected 0
weak: GREEN (0 failed of 2)
exit=0
$ node test_weak.js mutant
PASS small order: shippingCost(20) = 6.95, expected 6.95
PASS large order: shippingCost(250) = 0, expected 0
weak: GREEN (0 failed of 2)
exit=0
$ node test_strong.js .
PASS zero: shippingCost(0) = 6.95, expected 6.95
PASS small order: shippingCost(20) = 6.95, expected 6.95
PASS just below limit: shippingCost(99.99) = 6.95, expected 6.95
PASS exactly on limit: shippingCost(100) = 0, expected 0
PASS just above limit: shippingCost(100.01) = 0, expected 0
PASS large order: shippingCost(250) = 0, expected 0
strong: GREEN (0 failed of 6)
exit=0
$ node test_strong.js mutant
PASS zero: shippingCost(0) = 6.95, expected 6.95
PASS small order: shippingCost(20) = 6.95, expected 6.95
PASS just below limit: shippingCost(99.99) = 6.95, expected 6.95
FAIL exactly on limit: shippingCost(100) = 6.95, expected 0
PASS just above limit: shippingCost(100.01) = 0, expected 0
PASS large order: shippingCost(250) = 0, expected 0
strong: RED (1 failed of 6)
exit=1
$ diff shipping.js mutant/shipping.js
3c3
<   return orderTotal >= 100 ? 0 : 6.95;
---
>   return orderTotal > 100 ? 0 : 6.95;
