Ft/discovery

backend/src/models/cart-item.model.ts

@@ -30,5 +30,10 @@ const cartItemSchema = new Schema(
   },
 )
 
+cartItemSchema.index(
+  { user_id: 1, food_id: 1, status: 1 },
+  { unique: true, partialFilterExpression: { status: "active" } },
+)
+
 export type CartItemDocument = InferSchemaType<typeof cartItemSchema>
 export const CartItemModel = model<CartItemDocument>("CartItem", cartItemSchema)

backend/src/models/user-swipe.model.ts

@@ -29,5 +29,7 @@ const userSwipeSchema = new Schema(
   },
 )
 
+userSwipeSchema.index({ user_id: 1, food_id: 1 }, { unique: true })
+
 export type UserSwipeDocument = InferSchemaType<typeof userSwipeSchema>
 export const UserSwipeModel = model<UserSwipeDocument>("UserSwipe", userSwipeSchema)

backend/src/routes/swipe.routes.ts

@@ -51,20 +51,26 @@ swipeRouter.post("/", validateRequest({ body: swipeSchema }), async (req, res, n
     const userId = new Types.ObjectId(userIdRaw)
     const foodId = new Types.ObjectId(body.foodId)
 
-    const swipe = await UserSwipeModel.create({
-      user_id: userId,
-      food_id: foodId,
-      action: body.action,
-      timestamp: new Date(),
-    })
+    const swipe = await UserSwipeModel.findOneAndUpdate(
+      { user_id: userId, food_id: foodId },
+      { action: body.action, timestamp: new Date() },
+      {
+        upsert: true,
+        new: true,
+        setDefaultsOnInsert: true,
+      },
+    )
 
     if (body.action === "like") {
-      await CartItemModel.create({
-        user_id: userId,
-        food_id: foodId,
-        quantity: 1,
-        status: "active",
-      })
+      await CartItemModel.findOneAndUpdate(
+        { user_id: userId, food_id: foodId, status: "active" },
+        { $setOnInsert: { quantity: 1, status: "active" } },
+        {
+          upsert: true,
+          new: true,
+          setDefaultsOnInsert: true,
+        },
+      )
     }
 
     res.status(201).json({

backend/test/swipe.test.ts

@@ -8,21 +8,23 @@ test("POST /api/swipe with action=pass stores swipe and does not create cart ite
   const app = createApp()
 
   const originalFindById = FoodItemModel.findById
-  const originalSwipeCreate = UserSwipeModel.create
-  const originalCartCreate = CartItemModel.create
+  const originalSwipeUpsert = UserSwipeModel.findOneAndUpdate
+  const originalCartUpsert = CartItemModel.findOneAndUpdate
 
-  let cartCreateCalls = 0
+  let cartUpsertCalls = 0
 
   ;(FoodItemModel.findById as unknown as (...args: unknown[]) => Promise<unknown>) = async () => ({
     _id: "660000000000000000000100",
   })
-  ;(UserSwipeModel.create as unknown as (...args: unknown[]) => Promise<unknown>) = async () => ({
-    _id: "770000000000000000000001",
-  })
-  ;(CartItemModel.create as unknown as (...args: unknown[]) => Promise<unknown>) = async () => {
-    cartCreateCalls += 1
-    return {}
-  }
+  ;(UserSwipeModel.findOneAndUpdate as unknown as (...args: unknown[]) => Promise<unknown>) =
+    async () => ({
+      _id: "770000000000000000000001",
+    })
+  ;(CartItemModel.findOneAndUpdate as unknown as (...args: unknown[]) => Promise<unknown>) =
+    async () => {
+      cartUpsertCalls += 1
+      return {}
+    }
 
   const response = await request(app)
     .post("/api/swipe")
@@ -31,32 +33,34 @@ test("POST /api/swipe with action=pass stores swipe and does not create cart ite
 
   assert.equal(response.status, 201)
   assert.equal(response.body.swipe.action, "pass")
-  assert.equal(cartCreateCalls, 0)
+  assert.equal(cartUpsertCalls, 0)
 
   FoodItemModel.findById = originalFindById
-  UserSwipeModel.create = originalSwipeCreate
-  CartItemModel.create = originalCartCreate
+  UserSwipeModel.findOneAndUpdate = originalSwipeUpsert
+  CartItemModel.findOneAndUpdate = originalCartUpsert
 })
 
 test("POST /api/swipe with action=like stores swipe and creates cart item", async () => {
   const app = createApp()
 
   const originalFindById = FoodItemModel.findById
-  const originalSwipeCreate = UserSwipeModel.create
-  const originalCartCreate = CartItemModel.create
+  const originalSwipeUpsert = UserSwipeModel.findOneAndUpdate
+  const originalCartUpsert = CartItemModel.findOneAndUpdate
 
-  let cartCreateCalls = 0
+  let cartUpsertCalls = 0
 
   ;(FoodItemModel.findById as unknown as (...args: unknown[]) => Promise<unknown>) = async () => ({
     _id: "660000000000000000000100",
   })
-  ;(UserSwipeModel.create as unknown as (...args: unknown[]) => Promise<unknown>) = async () => ({
-    _id: "770000000000000000000001",
-  })
-  ;(CartItemModel.create as unknown as (...args: unknown[]) => Promise<unknown>) = async () => {
-    cartCreateCalls += 1
-    return {}
-  }
+  ;(UserSwipeModel.findOneAndUpdate as unknown as (...args: unknown[]) => Promise<unknown>) =
+    async () => ({
+      _id: "770000000000000000000001",
+    })
+  ;(CartItemModel.findOneAndUpdate as unknown as (...args: unknown[]) => Promise<unknown>) =
+    async () => {
+      cartUpsertCalls += 1
+      return {}
+    }
 
   const response = await request(app)
     .post("/api/swipe")
@@ -65,11 +69,11 @@ test("POST /api/swipe with action=like stores swipe and creates cart item", asyn
 
   assert.equal(response.status, 201)
   assert.equal(response.body.swipe.action, "like")
-  assert.equal(cartCreateCalls, 1)
+  assert.equal(cartUpsertCalls, 1)
 
   FoodItemModel.findById = originalFindById
-  UserSwipeModel.create = originalSwipeCreate
-  CartItemModel.create = originalCartCreate
+  UserSwipeModel.findOneAndUpdate = originalSwipeUpsert
+  CartItemModel.findOneAndUpdate = originalCartUpsert
 })
 
 test("POST /api/swipe returns 404 when foodId does not exist", async () => {

mobile/.env.example

@@ -1 +1,2 @@
 EXPO_PUBLIC_API_BASE_URL=http://localhost:5000
+EXPO_PUBLIC_DEMO_USER_ID=660000000000000000000001

mobile/README.md

@@ -27,6 +27,10 @@ npm run start
 
 - Deep link scheme is `discoverly`.
 - EAS profiles are defined in `eas.json`.
+- Discovery tab pulls from `GET /api/foods/discover`.
+- Swipe actions post to `POST /api/swipe`.
+- Feed prefetch starts when only 3 cards remain.
+- `expo-image` is used for image caching/prefetch to reduce flicker.
 - Do not hardcode secrets in source files. Keep sensitive values in EAS secrets
   or CI environment variables.
 - Only `EXPO_PUBLIC_*` variables should be exposed to client runtime code.