An employer shall not discharge, threaten to discharge, demote, suspend, discipline, or otherwise discriminate against an employee because the employee: (1) Has exercised, or attempted to exercise, any right provided under RCW
49.12.270 through
49.12.295; or (2) has filed a complaint, testified, or assisted in any proceeding under RCW
49.12.270 through
49.12.295.