hash optional; raise error if not set

nbgrader/preprocessors/instantiatetests.py

@@ -214,6 +214,8 @@ def preprocess_cell(self, cell, resources, index):
  # appears in the line before the self.autotest_delimiter token
  use_hash = (self.hashed_delimiter in line[:line.find(self.autotest_delimiter)])
  if use_hash:
+ if self.hash_template is None:
+ raise ValueError('Found a hashing delimiter, but the hash property has not been set in autotests.yml')
  self.log.debug('Hashing delimiter found, using template: %s', self.hash_template)
  else:
  self.log.debug('Hashing delimiter not found')
@@ -323,7 +325,7 @@ def _load_test_template_file(self, resources):
  self.success_code = tests.get('success', None)
 
  # get the hash code template
- self.hash_template = tests['hash']
+ self.hash_template = tests.get('hash', None)
 
  # get the hash code template
  self.check_template = tests['check']