Fix reform_documentation logic

taxcalc/calculator.py

@@ -1110,7 +1110,7 @@ def read_json_param_objects(reform, assump):
         return param_dict
 
     @staticmethod
-    def reform_documentation(params, policy_dicts=None):
+    def reform_documentation(params, growfactors, policy_dicts=None):
         """
         Generate reform documentation versus current-law policy.
 
@@ -1120,6 +1120,9 @@ def reform_documentation(params, policy_dicts=None):
             dictionary is structured like dict returned from
             the static Calculator.read_json_param_objects() method
 
+        growfactors: GrowFactors
+            GrowFactors object used to construct Calculator Policy object
+
         policy_dicts : list of dict or None
             each dictionary in list is a params['policy'] dictionary
             representing second and subsequent elements of a compound
@@ -1255,13 +1258,14 @@ def lines(text, num_indent_spaces, max_line_length=77):
         # create Policy object with current-law-policy values
         gdiff_base = GrowDiff()
         gdiff_base.update_growdiff(params['growdiff_baseline'])
-        gfactors_clp = GrowFactors()
+        assert isinstance(growfactors, GrowFactors)
+        gfactors_clp = copy.deepcopy(growfactors)
         gdiff_base.apply_to(gfactors_clp)
         clp = Policy(gfactors=gfactors_clp)
         # create Policy object with post-reform values
         gdiff_resp = GrowDiff()
         gdiff_resp.update_growdiff(params['growdiff_response'])
-        gfactors_ref = GrowFactors()
+        gfactors_ref = copy.deepcopy(growfactors)
         gdiff_base.apply_to(gfactors_ref)
         gdiff_resp.apply_to(gfactors_ref)
         ref = Policy(gfactors=gfactors_ref)