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test(heap): cover heapify up when removing an item - #2224
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renanmpimentel wants to merge 1 commit into
Open
renanmpimentel wants to merge 1 commit into
renanmpimentel wants to merge 1 commit into
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The heapifyUp branch of Heap.remove could be deleted without any test failing: no existing case moves a smaller item into the removed slot below a larger parent. Add one that observes the heap right after the removal.
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Problem
The
heapifyUpbranch ofHeap.removeis not exercised by any test. Replacingwith nothing keeps all heap, priority-queue and heap-sort tests green (41/41), even though the heap property is then violated after such a removal.
Change
Test-only. Add a
MinHeapcase where the last item moved into the removed slot is smaller than its new parent, and assert the heap layout right afterremove():With the
heapifyUpbranch removed the new test fails (Received: "1,5,2,4,7,3"); onmasterit passes. Full suite: 588 tests pass, lint clean.Found with supertest: mutation testing plus statement-removal analysis, with every finding confirmed by running the regression against the unmodified test.