Validate column heading.

Still need to show that it is the heading that is wrong.

app/utils.py

@@ -3,7 +3,7 @@ import re
 from functools import wraps
 from flask import (abort, session)
 
-from utils.process_csv import get_recipient_from_row
+from utils.process_csv import get_recipient_from_row, first_column_heading
 
 
 class BrowsableItem(object):
@@ -42,6 +42,11 @@ class InvalidPhoneError(Exception):
         self.message = message
 
 
+class InvalidHeaderError(Exception):
+    def __init__(self, message):
+        self.message = message
+
+
 def validate_phone_number(number):
     sanitised_number = number.replace('(', '')
     sanitised_number = sanitised_number.replace(')', '')
@@ -90,12 +95,21 @@ def validate_email_address(email_address):
 
 
 def validate_recipient(row, template_type):
+    validate_header_row(row, template_type)
     return {
         'email': validate_email_address,
         'sms': validate_phone_number
     }[template_type](get_recipient_from_row(row, template_type))
 
 
+def validate_header_row(row, template_type):
+    try:
+        column_heading = first_column_heading[template_type]
+        row[column_heading]
+    except KeyError as e:
+        raise InvalidHeaderError('Invalid header name, should be {}'.format(column_heading))
+
+
 def user_has_permissions(*permissions, or_=False):
     def wrap(func):
         @wraps(func)