Merge pull request #2524 from chusloj/read_json_error

Check for existence of reform and assumption json files

taxcalc/parameters.py

@@ -692,7 +692,19 @@ def convert_year_to_int(syr_dict):
             req.raise_for_status()
             txt = req.text
         else:
-            txt = obj
+            if isinstance(topkey, str) and (topkey == ''):
+                raise ValueError("topkey string is empty.")
+            if isinstance(obj, str):
+                if obj == '':
+                    raise ValueError("obj string is empty.")    
+                elif obj.endswith('.json') and not os.path.isfile(obj):
+                    raise FileNotFoundError("The .json file does not exist.")
+                elif ("{" and "}") in obj:
+                    txt = obj
+                else:
+                    raise ValueError("The JSON variable is misspecified.")
+            else:
+                raise ValueError("The JSON variable is misspecified.")
         # strip out //-comments without changing line numbers
         json_txt = re.sub('//.*', ' ', txt)
         # convert JSON text into a Python dictionary

taxcalc/tests/test_calculator.py

@@ -513,6 +513,16 @@ def test_read_bad_json_assump_file():
         Calculator.read_json_param_objects(None, list())
 
 
+def test_json_doesnt_exist():
+    """
+    Test JSON file which doesn't exist
+    """
+    with pytest.raises(FileNotFoundError):
+        Calculator.read_json_param_objects(None, './reforms/doesnt_exist.json')
+    with pytest.raises(FileNotFoundError):
+        Calculator.read_json_param_objects('./reforms/doesnt_exist.json', None)
+
+
 def test_calc_all():
     """
     Test calc_all method.