fix error handling test

Author: MthwRobinson

applpy/algebra.py

@@ -189,7 +189,7 @@ def product(random_variable_1, random_variable_2):
                 2. random_variable_2: A random variable
     Output:     1. The product of random_variable_1 and random_variable_2
     """
-    if random_variable_1.functional_form != random_variable_2.functional_form:
+    if random_variable_1.domain_type != random_variable_2.domain_type:
         raise RVError("both random variables must have the same functional form")
 
     if random_variable_1.is_continuous():

test_applpy/unit/test_rv.py

@@ -104,6 +104,7 @@ def test_bootstrap_rv_creates_discrete_pdf_with_frequencies():
     assert rv.support == [1, 2, 3]
     assert rv.func == [Rational(1, 4), Rational(1, 4), Rational(1, 2)]
 
+
 def test_fast_rv_round_trip_conversion_methods():
     rv = _discrete_pdf_bernoulli()
 
@@ -192,8 +193,8 @@ def test_two_rv_operations_for_continuous_and_discrete():
 def test_two_rv_operations_error_paths():
     discrete = _discrete_pdf()
 
-    with pytest.raises(RVError, match="both random variables must be discrete"):
-        product_discrete(_uniform_continuous_pdf(), discrete)
+    with pytest.raises(RVError, match="both random variables must have the same functional form"):
+        _uniform_continuous_pdf() * discrete
 
 
 def test_plotting_and_misc_utility_paths():