What is the test for estoppel in the context of a plaintiff’s application of estopple?

It is salutary to keep in mind Mr. Justice Cromwell’s caution against an overly broad application of cause of action estoppel. In Hoque at paras. 25, 30, and 37, he wrote: 25 The appellants submit, relying on these and similar statements, that cause of action estoppel is broad in scope and inflexible in application. With respect, I think this overstates the true position. In my view, this very broad language which suggests an inflexible application of cause of action estoppel to all matters that "could" have been raised does not fully reflect the present law. ... 30 The submission that all claims that could have been dealt with in the main action are barred is not borne out by the Canadian cases. With respect to matters not actually raised and decided, the test appears to me to be that the party should have raised the matter and, in deciding whether the party should have done so, a number of factors are considered. ... 37 Although many of these authorities cite with approval the broad language of Henderson v. Henderson, supra, to the effect that any matter which the parties had the opportunity to raise will be barred, I think, however, that this language is somewhat too wide. The better principle is that those issues which the parties had the opportunity to raise and, in all the circumstances, should have raised, will be barred. In determining whether the matter should have been raised, a court will consider whether the proceeding constitutes a collateral attack on the earlier findings, whether it simply asserts a new legal conception of facts previously litigated, whether it relies on "new" evidence that could have been discovered in the earlier proceeding with reasonable diligence, whether the two proceedings relate to separate and distinct causes of action and whether, in all the circumstances, the second proceeding constitutes an abuse of process. [Underline in original.]