You should have a wiring close to this (from Pololu web site Pololu - A4988 Stepper Motor Driver Carrier):
To test whether your stepper motor is broken or not, you don't need a library, simply code a serie of
digiatlWrite(pinstepper, High); delay(XX); digitalWtite(pinstepper, Low); delay(XX); in loop() and connect the Direction pin to Gnd.