Add test cases for back end

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

@@ -6,27 +6,95 @@
 def calculator():
     return AffordabilityCalculator()
 
+
 @pytest.fixture
 def zero_interest_calculator():
     return AffordabilityCalculator()
 
-def test_calculate_home_affordability_price(calculator):
+
+def test_process_affordability(calculator):
     calculator.process_affordability(1500.0, 20000.0, 5, 30, 50, 1.5, 0.75, 0.85)
     assert calculator.get_max_home_price() == 197638
     assert calculator.get_total_loan_cost() == 343296
     assert calculator.get_total_loan_principal() == 177638
     assert calculator.get_total_loan_interest() == 165658
 
-def test_calculate_home_affordability_price_with_zero_interest(zero_interest_calculator):
+
+def test_process_affordability_with_zero_interest(zero_interest_calculator):
     zero_interest_calculator.process_affordability(1500.0, 20000.0, 0, 30, 50, 1.5, 0.75, 0.85)
     assert zero_interest_calculator.get_max_home_price() == 283471
 
+
+def test_calculate_max_home_price(calculator):
+    calculator.process_affordability(1500.0, 20000.0, 5, 30, 50, 1.5, 0.75, 0.85)
+    assert calculator.get_max_home_price() == 197638
+
+
+def test_calculate_total_loan_price(calculator):
+    calculator.process_affordability(1500.0, 20000.0, 5, 30, 50, 1.5, 0.75, 0.85)
+    assert calculator.get_total_loan_cost() == 343296
+    assert calculator.get_total_loan_principal() == 177638
+
+
+def test_calculate_total_loan_principal(calculator):
+    calculator.process_affordability(1500.0, 20000.0, 5, 30, 50, 1.5, 0.75, 0.85)
+    assert calculator.get_total_loan_principal() == 177638
+
+
+def test_calculate_loan_interest(calculator):
+    calculator.process_affordability(1500.0, 20000.0, 5, 30, 50, 1.5, 0.75, 0.85)
+    assert calculator.get_total_loan_interest() == 165658
+
+
+def test_adjust_for_property_taxes_and_insurance(calculator):
+    monthly_payment = 1500.0 - 50  # desired monthly payment minus monthly HOA fees
+    interest_rate = 5 / 100 / 12
+    loan_term = 30 * 12
+    property_tax = 1.5 / 100 / 12
+    house_insurance = 0.75 / 100 / 12
+    pmi = 0.85 / 100
+    result = calculator._adjust_for_property_taxes_and_insurance(
+        monthly_payment,
+        299422,
+        20000.0,
+        interest_rate,
+        loan_term,
+        property_tax,
+        50,
+        house_insurance,
+        pmi,)
+    assert f"{result:.2f}" == "197638.00"
+
+
+def test_calculate_monthly_pmi(calculator):
+    pmi = 0.85 / 100
+    result = calculator._calculate_monthly_pmi_payment(
+        299422.0,
+        20000.0,
+        pmi
+    )
+    assert f"{result:.2f}" == "197.92"
+
+
+def test_calculate_monthly_mortgage_payment(calculator):
+    interest_rate = 5 / 100 / 12
+    loan_term = 30 * 12
+    result = calculator._calculate_monthly_mortgage_payment(
+        299422.0,
+        20000.0,
+        interest_rate,
+        loan_term
+    )
+    assert f"{result:.2f}" == "1500.00"
+
+
 def test_calculate_numerator(calculator):
     interest_rate = 6.125 / 100 / 12
     loan_term = 30 * 12
     result = calculator._calculate_numerator(interest_rate, loan_term)
     assert f"{result:.2f}" == "0.03"
 
+
 def test_calculate_denominator(calculator):
     interest_rate = 6.125 / 100 / 12
     loan_term = 30 * 12