What is the test for estoppel in res judicata?

There are two forms of res judicata: issue estoppel and cause of action estoppel. Issue estoppel arises when "a question has in substance been decided, or has in substance formed the ratio of, or been fundamental to, the decision in an earlier action between the same parties": Duedu v. Yiboe, [1961] A.C. 1040 (England P.C.); Schacher, supra. Cause of action estoppel arises when a: Court has adjudicated a claim between parties and a subsequent suit is brought between the same parties or their privies that is in some way related to the first. The judgment in the prior suit actually acts as a comprehensive declaration of the rights of all parties in respect of the matters in issue.