make possible to start without version file

Signed-off-by: Mattia Rizzolo <mattia@debian.org>

managetests/utils.py

@@ -29,9 +29,27 @@ def is_root_valid(path):
         print(")he specified root directory doesn't exist, please create it.")
         return False
 
-    required_files = ["config.json", "details.json", "version"]
+    # version file
+    file = path / 'version'
+    if not file.exists():
+        if not (path/'branches').exists() and not (path/'details.json').exists():
+            print('No version file found, and this seems an empty root, creating')
+            with open(file, 'w') as f:
+                f.write(ROOT_DIR_VERSION)
+        else:
+            print('Non-empty root missing version file.')
+            return False
+    elif not file.is_file():
+        print('There is a version non-file conflicting with the expectations.')
+        return False
+    else:
+        with open(file) as f:
+            ver = f.read().strip()
+        if ver != ROOT_DIR_VERSION:
+            print('Found wrong version ', ver)
+            return False
 
-    # make sure a branches directory is available:
+    # branches directory
     dir = path / 'branches'
     if not dir.exists():
         print('Creating the branches directory...')
@@ -40,14 +58,12 @@ def is_root_valid(path):
         print('There is a branches file conflicting with the expected directory')
         return False
 
+# TODO make possible to start without these two files
+    required_files = ["config.json", "details.json"]
     for file in required_files:
         file = path / file
         if not (file.exists() and file.is_file()):
             print("The required file %s does not exist" % file)
             return False
 
-    with (path / "version").open("r") as f:
-        if f.read().strip() != ROOT_DIR_VERSION:
-            return False
-
     return True