What is the test for assessing damages for wrongful conduct in a civil case?

In contrast, the principles applicable to the assessment of damages require the court to consider conditions or events unrelated to the defendant's wrongful conduct but which occurred either before or after the plaintiff’s injury and which impact the nature or extent of the compensation that should be awarded. Here, “[t]he governing principle is that the defendant need not put the plaintiff in a better position than his original position and should not compensate the plaintiff for any damages he would have suffered anyway”: Blackwater v. Plint, 2005 SCC 58 at para. 78.