test(trade): cover stale result dropdown tooltip guards

Author: mcagnion

spec/System/TestTradeQueryCurrency_spec.lua

@@ -62,4 +62,68 @@ describe("TradeQuery Currency Conversion", function()
             assert.are.equal(result, "5 chaos, 10 div")
         end)
     end)
+
+    describe("PriceItemRowDisplay tooltip guards", function()
+        local function makeTooltip()
+            return new("Tooltip")
+        end
+
+        local function primePriceRow(resultTbl, sortedResultTbl)
+            mock_tradeQuery.itemsTab = {
+                activeItemSet = {},
+                sockets = {},
+                slots = {},
+                AddItemTooltip = function() end,
+                build = { AddStatComparesToTooltip = function() end },
+            }
+            mock_tradeQuery.controls = { fullPrice = {}, pbNotice = {} }
+            mock_tradeQuery.totalPrice = {}
+            mock_tradeQuery.itemIndexTbl = {}
+            mock_tradeQuery.onlyWeightedBaseOutput = {}
+            mock_tradeQuery.resultTbl = resultTbl
+            mock_tradeQuery.sortedResultTbl = sortedResultTbl
+            mock_tradeQuery.slotTables = { [1] = { slotName = "Ring 1" } }
+
+            mock_tradeQuery:PriceItemRowDisplay(1, nil, 0, 20)
+            return mock_tradeQuery.controls.resultDropdown1
+        end
+
+        it("returns early when sortedResultTbl row disappears before tooltip evaluation", function()
+            local dropdown = primePriceRow({}, {})
+            local tooltip = makeTooltip()
+
+            mock_tradeQuery.sortedResultTbl[1] = nil
+
+            local ok, err = pcall(function()
+                dropdown.tooltipFunc(tooltip, "DROP", 1, nil)
+            end)
+
+            assert.is_true(ok, tostring(err))
+            assert.are.equal(0, #tooltip.lines)
+        end)
+
+        it("returns early when the selected result entry disappears before tooltip evaluation", function()
+            local dropdown = primePriceRow({
+                [1] = {
+                    {
+                        currency = "chaos",
+                        amount = 5,
+                        item_string = "Rarity: RARE\nBehemoth Hold\nGold Ring",
+                    }
+                }
+            }, {
+                [1] = { { index = 1 } }
+            })
+            local tooltip = makeTooltip()
+
+            mock_tradeQuery.resultTbl[1] = {}
+
+            local ok, err = pcall(function()
+                dropdown.tooltipFunc(tooltip, "DROP", 1, dropdown.list[1])
+            end)
+
+            assert.is_true(ok, tostring(err))
+            assert.are.equal(0, #tooltip.lines)
+        end)
+    end)
 end)