A: Thesave()method in the custom controller must be tested to ensure it works as intended and redirects to the correct page.
B: Setting parameters viaApexPages.currentPage().getParameters()is crucial to test scenarios where user input or URL parameters drive logic.
D: UsingTest.setCurrentPage(pageRef)is essential for simulating page context in unit tests.
Why not other options?
C: This statement does not belong to testing a custom controller.
B (second occurrence): It appears to be incorrectly formatted in the question.
Testing Apex Controllers