Add pytest test suite for Shopping List API\n\nTest coverage:\n- Root endpoint\n- Product CRUD\n- List CRUD\n- List items flow (add, update, delete, cascade)\n\nUse: pytest test_main.py\n\nOperation: shopping-list-api-2026-04-05\nWI3: Testing and validation

test_main.py

@@ -0,0 +1,132 @@
+import pytest
+from fastapi.testclient import TestClient
+from main import app, init_db
+import sqlite3
+import os
+
+client = TestClient(app)
+
+def setup_module(module):
+    # Use an in-memory database for tests
+    os.environ["DB_PATH"] = ":memory:"
+    init_db()
+
+def test_root():
+    r = client.get("/")
+    assert r.status_code == 200
+    assert r.json() == {"message": "Shopping List API"}
+
+def test_product_crud():
+    # Create
+    r = client.post("/products", json={"name": "Paper Plates", "sku": "PP-001"})
+    assert r.status_code == 201
+    product = r.json()
+    assert product["name"] == "Paper Plates"
+    assert product["sku"] == "PP-001"
+    product_id = product["id"]
+
+    # List
+    r = client.get("/products")
+    assert r.status_code == 200
+    assert len(r.json()) >= 1
+    assert any(p["id"] == product_id for p in r.json())
+
+    # Get
+    r = client.get(f"/products/{product_id}")
+    assert r.status_code == 200
+    assert r.json()["id"] == product_id
+
+    # Delete
+    r = client.delete(f"/products/{product_id}")
+    assert r.status_code == 200
+    assert r.json()["deleted"] == product_id
+
+    # Get deleted -> 404
+    r = client.get(f"/products/{product_id}")
+    assert r.status_code == 404
+
+def test_list_crud():
+    # Create
+    r = client.post("/lists", json={"name": "Picnic List"})
+    assert r.status_code == 201
+    lst = r.json()
+    assert lst["name"] == "Picnic List"
+    list_id = lst["id"]
+
+    # List
+    r = client.get("/lists")
+    assert r.status_code == 200
+    assert any(l["id"] == list_id for l in r.json())
+
+    # Get empty items
+    r = client.get(f"/lists/{list_id}")
+    assert r.status_code == 200
+    assert r.json()["items"] == []
+
+    # Delete
+    r = client.delete(f"/lists/{list_id}")
+    assert r.status_code == 200
+    assert r.json()["deleted"] == list_id
+
+def test_list_items_flow():
+    # Create two products
+    r1 = client.post("/products", json={"name": "Paper Plates"})
+    r2 = client.post("/products", json={"name": "Bread"})
+    p1 = r1.json()
+    p2 = r2.json()
+    p1_id, p2_id = p1["id"], p2["id"]
+
+    # Create a list
+    r = client.post("/lists", json={"name": "Picnic List"})
+    lst = r.json()
+    list_id = lst["id"]
+
+    # Add items
+    r = client.post(f"/lists/{list_id}/items", json={"product_id": p1_id, "quantity": 2})
+    assert r.status_code == 201
+    item1 = r.json()
+    assert item1["product_id"] == p1_id
+    assert item1["quantity"] == 2
+
+    r = client.post(f"/lists/{list_id}/items", json={"product_id": p2_id, "quantity": 1})
+    item2 = r.json()
+    assert r.status_code == 201
+    assert item2["product_id"] == p2_id
+    assert item2["quantity"] == 1
+
+    # List items
+    r = client.get(f"/lists/{list_id}/items")
+    assert r.status_code == 200
+    items = r.json()
+    assert len(items) == 2
+    qty_by_prod = {i["product_id"]: i["quantity"] for i in items}
+    assert qty_by_prod[p1_id] == 2
+    assert qty_by_prod[p2_id] == 1
+
+    # Get list with items
+    r = client.get(f"/lists/{list_id}")
+    assert r.status_code == 200
+    data = r.json()
+    assert len(data["items"]) == 2
+    assert any(i["product_name"] == "Paper Plates" for i in data["items"])
+
+    # Update quantity
+    r = client.patch(f"/lists/{list_id}/items/{item1['id']}", json={"quantity": 5})
+    assert r.status_code == 200
+    assert r.json()["quantity"] == 5
+
+    # Delete item
+    r = client.delete(f"/lists/{list_id}/items/{item2['id']}")
+    assert r.status_code == 200
+
+    # Verify item2 gone
+    r = client.get(f"/lists/{list_id}/items")
+    assert r.status_code == 200
+    assert len(r.json()) == 1
+
+    # Delete list cascades items
+    r = client.delete(f"/lists/{list_id}")
+    assert r.status_code == 200
+
+    r = client.get(f"/lists/{list_id}")
+    assert r.status_code == 404