What is the test for maintaining confidentiality of communications between a solicitor and client?

Solicitor‑client is described in Descôteaux v. Mierzwinski 1982 CanLII 22 (SCC), [1982] 1 S.C.R. 860 at 875, 141 D.L.R. (3d) 590 [Descôteaux] as follows: 1. The confidentiality of the communications between solicitor and client may be raised in any circumstances where such communications are likely to be disclosed without the client's consent. 2. Unless the law provides otherwise, when and to the extent that the legitimate exercise of a right would interfere with another person's right to have his communications with his lawyer kept confidential, the resulting conflict should be resolved in favour of protecting confidentiality. 3. When the law gives someone the authority to do something which, in the circumstances of the case, might interfere with that confidentiality, the decision to do so and the choice of means of exercising that authority should be determined with a view to not interfering with it except to the extent absolutely necessary in order to achieve the ends should [sic] by enabling legislation. 4. Acts providing otherwise in situations under paragraph 2 and enabling legislation referred to in paragraph 3 must be interpreted restrictively.