Split out Flat generator to be able to test it

lib/tree_builder.py

@@ -2,6 +2,7 @@ from typing import Dict
 from xmlrpc.client import Boolean
 
 from lib.db_revision import DBRevision
+from lib.flat_walker import FlatTreeWalker
 from lib.request import Request
 
 
@@ -50,6 +51,12 @@ class TreeNode:
     def print(self):
         self.walk(PrintWalker())
 
+    def as_flat_list(self):
+        """Return the tree as git commits to do"""
+        ftw = FlatTreeWalker()
+        self.walk(ftw)
+        return ftw.flats
+
     def as_list(self):
         """Return a list for test cases"""
         node = self