xpath - By is not a function in selenium nightwatch -

i not use default commands in selenium. below script

driver.findelement(by.xpath("//*[@id='lotstatus_q']/div/table/tbody/tr")); 

my script failing , result this:by not function

is there other items need install?

all other commands not functioning.

i think made mistake, cannot directly access selenium api nightwatch.js !

nightwatch override of webdriver wire protocole (exposed selenium rest api) https://code.google.com/p/selenium/wiki/jsonwireprotocol

but can use xpath selectors nightwatch:

client.usexpath().waitforelementvisible("//*[@id='lotstatus_q']/div/table/tbody/tr") 

read doc xpath: http://nightwatchjs.org/guide#using-xpath-selectors