diff --git a/tests/testSlotAction.cpp b/tests/testSlotAction.cpp
index f17e8fa..96f12fd 100644
--- a/tests/testSlotAction.cpp
+++ b/tests/testSlotAction.cpp
@@ -468,3 +468,134 @@ VF_TEST(anAbandonedDragGivesEverythingBackToTheCursor) {
     session.menu.slot(0).cell.stack = makeStack(ItemId::Stone, 12);
     session.click(ClickKind::Left, 0);
 
+    session.click(ClickKind::DragLeftStart, -1);
+    CHECK(session.drag.active);
+    SlotActionResult released = session.click(ClickKind::DragLeftEnd, -1);
+    CHECK(released.applied);
+    CHECK_EQ(released.moved, 0);
+    CHECK_EQ(session.cursor.held.count, 12);
+    CHECK(!session.drag.active);
+
+    // A drag end for the other button is not this drag's business.
+    session.click(ClickKind::DragLeftStart, 1);
+    CHECK(!session.click(ClickKind::DragRightEnd, -1).applied);
+    CHECK(session.drag.active);
+}
+
+VF_TEST(aDragNeverStartsWithAnEmptyCursor) {
+    Session session(MenuKind::Chest);
+    session.menu.slot(0).cell.stack = makeStack(ItemId::Stone, 12);
+    CHECK(!session.click(ClickKind::DragLeftStart, 0).applied);
+    CHECK(!session.drag.active);
+    CHECK(!session.click(ClickKind::DragLeftAdd, 1).applied);
+    CHECK_EQ(session.menu.stackAt(0).count, 12);
+}
+
+VF_TEST(throwingFromTheCursorReportsExactlyWhatLeftTheMenu) {
+    Session session(MenuKind::Chest);
+    session.menu.slot(0).cell.stack = makeStack(ItemId::Gravel, 6);
+    session.click(ClickKind::Left, 0);
+
+    SlotActionResult one = session.click(ClickKind::DropOne, -1);
+    CHECK(one.applied);
+    CHECK_EQ(one.dropped, 1);
+    CHECK_EQ(one.droppedStacks.size(), 1u);
+    CHECK_EQ(one.droppedStacks[0].count, 1);
+    CHECK_EQ(session.cursor.held.count, 5);
+
+    SlotActionResult all = session.click(ClickKind::DropStack, -1);
+    CHECK_EQ(all.dropped, 5);
+    CHECK(session.cursor.empty());
+    CHECK(!session.click(ClickKind::DropStack, -1).applied);
+}
+
+VF_TEST(throwingFromASlotOnlyWorksWithAnEmptyHand) {
+    Session session(MenuKind::Chest);
+    session.menu.slot(0).cell.stack = makeStack(ItemId::Gravel, 6);
+
+    SlotActionResult one = session.click(ClickKind::DropOne, 0);
+    CHECK(one.applied);
+    CHECK_EQ(one.dropped, 1);
+    CHECK_EQ(session.menu.stackAt(0).count, 5);
+
+    SlotActionResult rest = session.click(ClickKind::DropStack, 0);
+    CHECK_EQ(rest.dropped, 5);
+    CHECK(session.menu.stackAt(0).empty());
+    CHECK(!session.click(ClickKind::DropOne, 0).applied);
+
+    session.menu.slot(1).cell.stack = makeStack(ItemId::Stone, 4);
+    session.click(ClickKind::Left, 1);
+    session.menu.slot(2).cell.stack = makeStack(ItemId::Sand, 4);
+    CHECK(!session.click(ClickKind::DropOne, 2).applied);
+    CHECK_EQ(session.menu.stackAt(2).count, 4);
+}
+
+VF_TEST(theResultSlotCannotBeUsedAsStorageByAnyClick) {
+    Session session(MenuKind::CraftingTable);
+    int result = session.menu.layout().resultSlot;
+    session.menu.slot(0).cell.stack = makeStack(ItemId::Stone, 10);
+    session.click(ClickKind::Left, 0);
+
+    CHECK(!session.click(ClickKind::Left, result).applied);
+    CHECK(!session.click(ClickKind::Right, result).applied);
+    CHECK(!session.click(ClickKind::DragLeftStart, result).applied ||
+          session.drag.paintedSlots.empty());
+    session.drag.reset();
+    CHECK(session.menu.stackAt(result).empty());
+    CHECK_EQ(session.cursor.held.count, 10);
+}
+
+VF_TEST(takingAResultOntoAMatchingCursorKeepsCrafting) {
+    Session session(MenuKind::CraftingTable);
+    CraftingView grid = session.menu.crafting();
+    grid.input(0, 0) = makeStack(ItemId::Wood, 4);
+    grid.refresh();
+
+    session.click(ClickKind::Left, session.menu.layout().resultSlot);
+    CHECK_EQ(session.cursor.held.count, 4);
+    CHECK(session.cursor.held.item == ItemId::Planks);
+
+    SlotActionResult second = session.click(ClickKind::Left, session.menu.layout().resultSlot);
+    CHECK(second.applied);
+    CHECK(second.craftedResult);
+    CHECK_EQ(session.cursor.held.count, 8);
+    CHECK_EQ(grid.input(0, 0).count, 2);
+
+    // A cursor holding something else cannot take the result.
+    session.cursor.held = makeStack(ItemId::Stone, 1);
+    CHECK(!session.click(ClickKind::Left, session.menu.layout().resultSlot).applied);
+    CHECK_EQ(grid.input(0, 0).count, 2);
+}
+
+VF_TEST(noSequenceOfChestClicksEverCreatesOrDestroysAnItem) {
+    WalkCoverage walk = runConservationWalk(MenuKind::Chest, 20260904u, 500);
+    // A walk that never actually did anything would pass the invariant for the
+    // wrong reason, so the coverage itself is asserted: most click kinds have
+    // to have landed, and items have to have really left through the drop path.
+    CHECK(walk.applied > 100);
+    CHECK(walk.dropped > 0);
+    CHECK(walk.distinctKindsApplied >= 12);
+}
+
+VF_TEST(theSameInvariantHoldsOnAFilteredFurnaceScreen) {
+    WalkCoverage walk = runConservationWalk(MenuKind::Furnace, 77u, 500);
+    CHECK(walk.applied > 100);
+    CHECK(walk.dropped > 0);
+    CHECK(walk.distinctKindsApplied >= 12);
+}
+
+VF_TEST(theSameInvariantHoldsOnAHopperAndOnALargeChest) {
+    WalkCoverage hopper = runConservationWalk(MenuKind::Hopper, 4242u, 500);
+    WalkCoverage large = runConservationWalk(MenuKind::LargeChest, 991u, 500);
+    CHECK(hopper.applied > 100);
+    CHECK(large.applied > 100);
+    CHECK(hopper.dropped > 0);
+    CHECK(large.dropped > 0);
+}
+
+VF_TEST(theConservationWalkIsReproducibleFromItsSeed) {
+    CHECK_EQ(runConservationWalk(MenuKind::Chest, 555u, 500).applied,
+             runConservationWalk(MenuKind::Chest, 555u, 500).applied);
+    CHECK(runConservationWalk(MenuKind::Chest, 555u, 500).applied !=
+          runConservationWalk(MenuKind::Chest, 556u, 500).applied);
+}