What is the test for assessing damages when a defence has been struck?

The principles for assessment in these circumstances are summarized in McIsaac v. Healthy Body Services Inc., 2009 BCSC 1716, para. 44: a) Generally, if a statement of defence is struck, the defendant is deemed to have admitted the allegations of fact contained in the statement of claim. Where the defence is struck with damages to be assessed, all that remains in issue is the assessment of damages. b) The rule that the defendant is deemed to have admitted all of the allegations of fact in the statement of claim is not immutable. The plaintiff must prove his or her claim for damages. The court retains the discretion, which it must exercise judicially, to permit the defendant to adduce evidence and cross-examine on issues essential to a fair and just determination of the loss actually sustained by the plaintiff. c) In some cases, it may not be possible to draw a bright line between facts going to liability and facts relating only to the assessment of quantum of damages. d) The assessment of damages will be limited to the damages claimed in the pleadings.