Add reusable crafting stations, recipes and validation

tests/CraftLedgerTests.cs

@@ -0,0 +1,72 @@
+namespace Cthangover.Mods.Crafting.Tests
+{
+    using System.Collections.Generic;
+    using System.Linq;
+    using Cthangover.Core.Items;
+    using Cthangover.Core.Mods.Resolvers;
+    using Cthangover.Core.Mods.Testing;
+
+    /// <summary>Refused recipes preserve every stack; duplicate rows are a combined requirement, never a discount.</summary>
+    public class CraftLedgerTests
+    {
+        private static List<string> Goods() => Entities.Collect<ItemInfo>().Keys.Take(2).ToList();
+
+        private static RecipeInfo Recipe(string input, string output) => new()
+        {
+            ID = "test/craft", Time = 5,
+            Input = new List<IngredientInfo> { new() { ID = input, Count = 2 } },
+            Output = new List<IngredientInfo> { new() { ID = output, Count = 1 } },
+        };
+
+        [ModTest("craft/batch_spends_inputs_and_adds_products")]
+        static void Batch(ModTestContext ctx)
+        {
+            var ids = Goods();
+            var bag = new Inventory();
+            bag.Add(ids[0], 7);
+            var recipe = Recipe(ids[0], ids[1]);
+            ModAssert.True(CraftLedger.CanCraft(bag, recipe, 3), "three batches fit");
+            ModAssert.Equal(7, bag.CheckCount(ids[0]), "preview does not consume");
+            ModAssert.True(CraftLedger.TryCraft(bag, recipe, 3), "craft succeeds");
+            ModAssert.Equal(1, bag.CheckCount(ids[0]), "six ingredients consumed");
+            ModAssert.Equal(3, bag.CheckCount(ids[1]), "three products created");
+        }
+
+        [ModTest("craft/missing_duplicate_and_invalid_entries_are_all_or_nothing")]
+        static void Refusals(ModTestContext ctx)
+        {
+            var ids = Goods();
+            var bag = new Inventory();
+            bag.Add(ids[0], 3);
+            var recipe = Recipe(ids[0], ids[1]);
+            recipe.Input.Add(new IngredientInfo { ID = ids[0], Count = 2 });
+            ModAssert.False(CraftLedger.TryCraft(bag, recipe), "duplicate rows require four, not two");
+            recipe.Input.RemoveAt(1);
+            recipe.Output[0].ID = "missing/craft/product";
+            ModAssert.False(CraftLedger.TryCraft(bag, recipe), "missing product refuses consumption");
+            recipe.Output[0].ID = ids[1];
+            recipe.Input.Add(new IngredientInfo { ID = "missing/craft/input", Count = 1 });
+            ModAssert.False(CraftLedger.TryCraft(bag, recipe), "missing ingredient is not silently dropped");
+            recipe.Input.RemoveAt(1);
+            ModAssert.False(CraftLedger.TryCraft(bag, recipe, 0), "zero batch");
+            ModAssert.False(CraftLedger.TryCraft(bag, recipe, -1), "negative batch");
+            ModAssert.False(CraftLedger.TryCraft(bag, recipe, int.MaxValue), "overflowing batch");
+            recipe.Input[0].Count = -1;
+            ModAssert.False(CraftLedger.TryCraft(bag, recipe), "negative ingredient");
+            ModAssert.Equal(3, bag.CheckCount(ids[0]), "all refusals left inputs untouched");
+            ModAssert.Equal(0, bag.CheckCount(ids[1]), "all refusals left products untouched");
+        }
+
+        [ModTest("craft/output_overflow_refuses_before_consumption")]
+        static void Overflow(ModTestContext ctx)
+        {
+            var ids = Goods();
+            var bag = new Inventory();
+            bag.Add(ids[0], 4);
+            bag.Add(ids[1], int.MaxValue);
+            ModAssert.False(CraftLedger.TryCraft(bag, Recipe(ids[0], ids[1])), "full output stack");
+            ModAssert.Equal(4, bag.CheckCount(ids[0]), "input untouched");
+            ModAssert.Equal(int.MaxValue, bag.CheckCount(ids[1]), "output untouched");
+        }
+    }
+}