Clear inventory grid before crafting

craft.lua

@@ -11,7 +11,7 @@ local inventory = component.inventory_controller
 RESULT_SLOT = 4
 
 -- robots inventory is 4 wide and crafting uses the top left portion
-local slot_map = {
+SLOT_MAP = {
     1, 2, 3,
     5, 6, 7,
     9, 10, 11
@@ -177,6 +177,20 @@ local function fetch_item(item, output_slot, count)
     return false
 end
 
+---clear the 3x3 grid of any leftover items
+local function clear_crafting_space()
+    for _, slot in ipairs(SLOT_MAP) do
+        if inventory.getStackInInternalSlot(slot) then
+            robot.select(slot)
+            store_item()
+        end
+    end
+    if inventory.getStackInInternalSlot(RESULT_SLOT) then
+        robot.select(RESULT_SLOT)
+        store_item()
+    end
+end
+
 ---accepts a recipe table containing result and ingredients
 ---@param recipe table
 ---@param count number how many items to craft
@@ -188,7 +202,7 @@ local function craft_single_recipe(recipe, count)
     end
     for i, ingredient in pairs(recipe.shape) do
         -- print('Fetching ' .. ingredient)
-        if not fetch_item(ingredient, slot_map[i], count) then
+        if not fetch_item(ingredient, SLOT_MAP[i], count) then
             print('Failed to fetch ' .. ingredient)
             confirm()
         end
@@ -391,6 +405,8 @@ local function craft_item(search)
         return false
     end
 
+    clear_crafting_space()
+
     -- proceed to crafting the things
     for i, rec in ipairs(crafting_order) do
         print('Step #' .. i .. ' - ' .. rec.result)