add mypyyyyyyy

Author: hnomichith

src/supermarket_receipt/README.md

@@ -13,3 +13,8 @@ The starting position for this exercise contains the code for setting up the Tel
 - make a venv
 - install requirements, e.g. `python -m pip install -r requirements.txt`
 - use pytest to run the tests
+
+## Mypy
+
+You can validate the types with the following command: `mypy src/supermarket_receipt/`. Only a missing stub for appovaltests should be raised by default.
+

src/supermarket_receipt/requirements.txt

@@ -2,3 +2,4 @@ pytest==7.3.2
 approvaltests==10.0.0
 pytest-approvaltests==0.2.4
 coverage
+mypy

src/supermarket_receipt/src/catalog.py

@@ -2,7 +2,7 @@
 
 
 class SupermarketCatalog:
-    def __init__(self):
+    def __init__(self) -> None:
         self.products: dict[str, Product] = {}
         self.prices: dict[str, float] = {}
 

src/supermarket_receipt/src/receipt.py

@@ -15,7 +15,7 @@ def __init__(self) -> None:
         self._discounts: list[Discount] = []
 
     def total_price(self) -> float:
-        total = 0
+        total = 0.0
         for item in self.items:
             total += item.total_price
         for discount in self.discounts:

src/supermarket_receipt/src/teller.py

@@ -6,7 +6,7 @@
 
 class Teller:
 
-    def __init__(self, catalog):
+    def __init__(self, catalog: SupermarketCatalog) -> None:
         self.catalog: SupermarketCatalog = catalog
         self.offers: dict[Product, Offer] = {}
 

src/supermarket_receipt/tests/receipt_printer.py

@@ -1,4 +1,4 @@
-from src.model_objects import ProductUnit
+from src.model_objects import ProductUnit, Discount
 from src.receipt import Receipt, ReceiptItem
 
 

src/supermarket_receipt/tests/test_supermarket.py

@@ -1,5 +1,4 @@
 import approvaltests
-import pytest
 
 from src.model_objects import SpecialOfferType, Product
 from tests.receipt_printer import ReceiptPrinter