test(trade): cover stale result dropdown tooltip guards

Author: mcagnion

spec/System/TestTradeQuery_spec.lua

@@ -0,0 +1,57 @@
+describe("TradeQuery", function()
+    describe("result dropdown tooltipFunc", function()
+        -- Builds a TradeQuery with the strict minimum needed for
+        -- PriceItemRowDisplay to construct row 1 without exploding. Only the
+        -- two itemsTab subtables read by the slot lookup at the top of
+        -- PriceItemRowDisplay need to be created here; everything else either
+        -- lives behind a callback we never trigger, or is already initialized
+        -- by the TradeQuery constructor.
+        local function newTradeQuery(state)
+            local tq = new("TradeQuery", { itemsTab = {} })
+            tq.itemsTab.activeItemSet = {}
+            tq.itemsTab.slots         = {}
+            tq.slotTables[1] = { slotName = "Ring 1" }
+            if state.resultTbl       then tq.resultTbl       = state.resultTbl       end
+            if state.sortedResultTbl then tq.sortedResultTbl = state.sortedResultTbl end
+            return tq
+        end
+
+        -- Builds row 1 of the trader UI and returns the dropdown that owns the
+        -- tooltipFunc we want to exercise.
+        local function buildRow1Dropdown(tq)
+            tq:PriceItemRowDisplay(1, nil, 0, 20)
+            return tq.controls.resultDropdown1
+        end
+
+        it("returns early when sortedResultTbl[row_idx] is missing", function()
+            -- No sorted results at all -> first guard must short-circuit.
+            local tq = newTradeQuery({})
+            local dropdown = buildRow1Dropdown(tq)
+            local tooltip = new("Tooltip")
+
+            assert.has_no.errors(function()
+                dropdown.tooltipFunc(tooltip, "DROP", 1, nil)
+            end)
+            assert.are.equal(0, #tooltip.lines)
+        end)
+
+        it("returns early when the backing result entry has been cleared", function()
+            -- The dropdown must be built against a valid result so that
+            -- PriceItemRowDisplay's construction loop succeeds; we wipe
+            -- resultTbl[1] only afterwards, to simulate a stale tooltip
+            -- callback firing after the results were invalidated.
+            local tq = newTradeQuery({
+                resultTbl       = { [1] = { [1] = { item_string = "Rarity: RARE\nBehemoth Hold\nGold Ring" } } },
+                sortedResultTbl = { [1] = { { index = 1 } } },
+            })
+            local dropdown = buildRow1Dropdown(tq)
+            tq.resultTbl[1] = {}
+            local tooltip = new("Tooltip")
+
+            assert.has_no.errors(function()
+                dropdown.tooltipFunc(tooltip, "DROP", 1, nil)
+            end)
+            assert.are.equal(0, #tooltip.lines)
+        end)
+    end)
+end)