Add unit tests for imperial weight form

Author: miriam-z

lung_cancer_screening/questions/tests/unit/forms/test_imperial_weight_form.py

@@ -0,0 +1,78 @@
+from django.test import TestCase
+
+from ....models.participant import Participant
+from ....forms.imperial_weight_form import ImperialWeightForm
+
+class TestImperialWeightForm(TestCase):
+    def setUp(self):
+        self.participant = Participant.objects.create(unique_id="1234567890")
+        self.response_set = self.participant.responseset_set.create(
+            weight_metric=1704
+        )
+
+    def test_is_valid_with_valid_input(self):
+        form = ImperialWeightForm(
+            participant=self.participant,
+            instance=self.response_set,
+            data={
+                "weight_imperial_0": "5",  # stone
+                "weight_imperial_1": "9"   # pounds
+            }
+        )
+
+        self.assertTrue(form.is_valid())
+
+    def test_converts_stone_and_pounds_to_kilograms_integer(self):
+        form = ImperialWeightForm(
+            participant=self.participant,
+            instance=self.response_set,
+            data={
+                "weight_imperial_0": "5",  # stone
+                "weight_imperial_1": "9"   # pounds
+            }
+        )
+
+        self.assertTrue(form.is_valid(), f"Form errors: {form.errors}")
+        self.assertEqual(form.cleaned_data['weight_imperial'], 79)
+
+    def test_setting_weight_imperial_clears_weight_metric(self):
+        form = ImperialWeightForm(
+            instance=self.response_set,
+            participant=self.participant,
+            data={
+                "weight_imperial_0": "5",  # stone
+                "weight_imperial_1": "9"   # pounds
+            }
+        )
+        form.save()
+        self.assertEqual(self.response_set.weight_metric, None)
+
+    def test_is_invalid_with_missing_data(self):
+        form = ImperialWeightForm(
+            participant=self.participant,
+            instance=self.response_set,
+            data={
+                "weight_imperial_0": "5",
+                # missing pounds
+            }
+        )
+        self.assertFalse(form.is_valid())
+        self.assertEqual(
+            form.errors["weight_imperial"],
+            ["Enter your weight."]
+        )
+
+    def test_is_invalid_when_given_a_decimal_stone_value(self):
+        form = ImperialWeightForm(
+            participant=self.participant,
+            instance=self.response_set,
+            data={
+                "weight_imperial_0": "5.2",
+                "weight_imperial_1": "0"
+            }
+        )
+        self.assertFalse(form.is_valid())
+        self.assertEqual(
+            form.errors["weight_imperial"],
+            ["Stone must be in whole numbers."]
+        )