Add default values to constructor for issue #72

Set all variables in affordability_calculator constructor to default to
"0". Created a test case for a scenario where user does not enter
information, so the constructor defaults the values to "0".

Author: randy-shreeves

home-choice-pro/models/affordability_calculator.py

@@ -29,8 +29,8 @@ class AffordabilityCalculator:
     hoa_monthly_fee: float
 
     # Constructor
-    def __init__(self, monthly_payment: str, down_payment: str, interest_rate: str, loan_term: str,
-                 hoa_monthly_fee: str):
+    def __init__(self, monthly_payment: str = "0", down_payment: str = "0",
+                 interest_rate: str = "0", loan_term: str = "0", hoa_monthly_fee: str = "0"):
         """Initializes class variables."""
         self.monthly_payment = self.convert_string_number_into_float(monthly_payment)
         self.down_payment = self.convert_string_number_into_float(down_payment)

home-choice-pro/tests/test_models/test_affordability_calculator.py

@@ -10,6 +10,10 @@ def calculator():
 def zero_interest_calculator():
     return AffordabilityCalculator("1500.0", "20000.0", "0", "30", "50")
 
+@pytest.fixture
+def empty_calculator_fields():
+    return AffordabilityCalculator()
+
 
 def test_user_inputs_are_valid(calculator):
     assert calculator._user_inputs_are_valid() == True
@@ -35,6 +39,11 @@ def test_calculate_home_affordability_price_with_zero_interest(zero_interest_cal
     assert result != "Invalid User Inputs"
     assert result == "542000"
 
+def test_empty_calculator_fields(empty_calculator_fields):
+    result = empty_calculator_fields.calculate_home_affordability_price()
+    assert result != "Invalid User Inputs"
+    assert result == "0"
+
 
 def test_calculate_total_home_loan_price(calculator):
     calculator.calculate_home_affordability_price()