When you call console.assert the first argument is evaluated, if it is true then the message is printed to the screen, otherwise nothing happens

See https://developer.mozilla.org/en-US/docs/Web/API/console/assert_static

rrweb's console recorder has no special handling for assert so we always print the message including the evaluated first arg

this gives an incorrect view of what could have been seen by the browser user

printed when false

we should capture this and print everything except the first arg

nothing printed when true

we should not capture this

error printed when referencing undefined variable

this wouldn't hit the console recorder (but its error would)