Make an assertion, error will be thrown if expr does not have truthy value.

Make an assertion that actual and expected are equal, deeply. If not deeply equal, then throw.

Executes a function which returns a promise, expecting it to throw or reject. If it does not, then it throws. An error class and a string that should be included in the error message can also be asserted.

Creates a Promise with the reject and resolve functions placed as methods on the promise object itself. It allows you to do: