Start refactoring of the trigger system:

- Move each trigger handler into its own file
- Add dictionary helper classes for easier reading and writing of dict-based data
- Extract the web hook payload -> internal representation building for each trigger system
- Add tests for this transformation
- Remove support for Github archived-based building

util/dict_wrappers.py

@@ -0,0 +1,79 @@
+import json
+from jsonpath_rw import parse
+
+class SafeDictSetter(object):
+  """ Specialized write-only dictionary wrapper class that allows for setting
+      nested keys via a path syntax.
+
+      Example:
+        sds = SafeDictSetter()
+        sds['foo.bar.baz'] = 'hello' # Sets 'foo' = {'bar': {'baz': 'hello'}}
+        sds['somekey'] = None # Does not set the key since the value is None
+  """
+  def __init__(self, initial_object=None):
+    self._object = initial_object or {}
+
+  def __setitem__(self, path, value):
+    self.set(path, value)
+
+  def set(self, path, value, allow_none=False):
+    """ Sets the value of the given path to the given value. """
+    if value is None and not allow_none:
+      return
+
+    pieces = path.split('.')
+    current = self._object
+
+    for piece in pieces[:len(pieces)-1]:
+      current_obj = current.get(piece, {})
+      if not isinstance(current_obj, dict):
+        raise Exception('Key %s is a non-object value: %s' % (piece, current_obj))
+
+      current[piece] = current_obj
+      current = current_obj
+
+    current[pieces[-1]] = value
+
+  def dict_value(self):
+    """ Returns the dict value built. """
+    return self._object
+
+  def json_value(self):
+    """ Returns the JSON string value of the dictionary built. """
+    return json.dumps(self._object)
+
+
+class JSONPathDict(object):
+  """ Specialized read-only dictionary wrapper class that uses the jsonpath_rw library
+      to access keys via an X-Path-like syntax.
+
+      Example:
+        pd = JSONPathDict({'hello': {'hi': 'there'}})
+        pd['hello.hi'] # Returns 'there'
+  """
+  def __init__(self, dict_value):
+    """ Init the helper with the JSON object.
+    """
+    self._object = dict_value
+
+  def __getitem__(self, path):
+    def raise_exception():
+      raise KeyError('Unknown path: %s' % path)
+
+    return self.get(path, not_found_handler=raise_exception)
+
+  def get(self, path, not_found_handler=None):
+    """ Returns the value found at the given path. Path is a json-path expression. """
+    jsonpath_expr = parse(path)
+    matches = jsonpath_expr.find(self._object)
+    if not matches:
+      return not_found_handler() if not_found_handler else None
+
+    match = matches[0].value
+    if not match:
+      return not_found_handler() if not_found_handler else None
+
+    if isinstance(match, dict):
+      return JSONPathDict(match)
+
+    return match