add tests

counter/tests/test_formula.py

@@ -0,0 +1,59 @@
+from django.test import TestCase
+
+from counter.baker_recipes import product_recipe
+from counter.forms import ProductFormulaForm
+
+
+class TestFormulaForm(TestCase):
+    @classmethod
+    def setUpTestData(cls):
+        cls.products = product_recipe.make(
+            selling_price=iter([1.5, 1, 1]),
+            special_selling_price=iter([1.4, 0.9, 0.9]),
+            _quantity=3,
+            _bulk_create=True,
+        )
+
+    def test_ok(self):
+        form = ProductFormulaForm(
+            data={
+                "result": self.products[0].id,
+                "products": [self.products[1].id, self.products[2].id],
+            }
+        )
+        assert form.is_valid()
+        formula = form.save()
+        assert formula.result == self.products[0]
+        assert set(formula.products.all()) == set(self.products[1:])
+
+    def test_price_invalid(self):
+        self.products[0].selling_price = 2.1
+        self.products[0].save()
+        form = ProductFormulaForm(
+            data={
+                "result": self.products[0].id,
+                "products": [self.products[1].id, self.products[2].id],
+            }
+        )
+        assert not form.is_valid()
+        assert form.errors == {
+            "result": [
+                "Le résultat ne peut pas être plus cher "
+                "que le total des autres produits."
+            ]
+        }
+
+    def test_product_both_in_result_and_products(self):
+        form = ProductFormulaForm(
+            data={
+                "result": self.products[0].id,
+                "products": [self.products[0].id, self.products[1].id],
+            }
+        )
+        assert not form.is_valid()
+        assert form.errors == {
+            "__all__": [
+                "Un même produit ne peut pas être à la fois "
+                "le résultat et un élément de la formule."
+            ]
+        }