What is the test for judicial review of a government's interpretation of the law?

I acknowledge that this power exists, but in my view, it should be exercised very prudently. The dissenting judges in Doucet‑Boudreau stated (and the judges of the majority did not contradict them on this point): [the role of the courts] is to declare what the law is, contribute to its development and to give claimants such relief in the form of declarations, interpretation and orders as will be needed to remedy infringements of constitutional and legal rights by public authorities. Beyond these functions, an attitude of restraint remains all the more justified, given that . . . Canada has maintained a tradition of compliance by governments and public servants with judicial interpretations of the law and court orders. Doucet‑Boudreau v. Nova Scotia (Minister of Education), supra, paragraph 106.