Preserve keys that are only in original buildconfig, except those nes…

…ted in 'strategy'

osbs/utils.py

@@ -43,22 +43,27 @@ def graceful_chain_get(d, *args):
     return t
 
 
-def buildconfig_update(orig, new):
+def buildconfig_update(orig, new, remove_nonexistent_keys=False):
     """Performs update of given `orig` BuildConfig with values from `new` BuildConfig.
     Both BuildConfigs have to be represented as `dict`s.
 
     This function:
     - adds all key/value pairs to `orig` from `new` that are missing
     - replaces values in `orig` for keys that are in both
-    - removes key/value pairs from `orig` for keys that are not in `new`
+    - removes key/value pairs from `orig` for keys that are not in `new`,
+      but only in dicts nested inside `strategy` key
+      (see https://github.com/projectatomic/osbs-client/pull/273#issuecomment-148038314)
     """
     if isinstance(orig, dict) and isinstance(new, dict):
-        missing = set(orig.keys()) - set(new.keys())
-        for k in missing:
-            orig.pop(k)
+        if remove_nonexistent_keys:
+            missing = set(orig.keys()) - set(new.keys())
+            for k in missing:
+                orig.pop(k)
         for k, v in new.items():
+            if k == 'strategy':
+                remove_nonexistent_keys = True
             if isinstance(orig.get(k, None), dict) and isinstance(v, dict):
-                buildconfig_update(orig[k], v)
+                buildconfig_update(orig[k], v, remove_nonexistent_keys)
             else:
                 orig[k] = v
 

tests/test_utils.py

@@ -21,10 +21,10 @@
 
 
 def test_buildconfig_update():
-    x = {'a': 'a', 'b': {'b1': 'B1', 'b2': 'B2'}, 'd': 'D'}
-    y = {'a': 'A', 'b': {'b1': 'newB1', 'b3': 'B3'}, 'c': 'C'}
+    x = {'a': 'a', 'strategy': {'b1': 'B1', 'b2': 'B2', 'b11': {'x': 'y'}}, 'd': 'D'}
+    y = {'a': 'A', 'strategy': {'b1': 'newB1', 'b3': 'B3', 'b11': {}}, 'c': 'C'}
     buildconfig_update(x, y)
-    assert x == {'a': 'A', 'b': {'b1': 'newB1', 'b3': 'B3'}, 'c': 'C'}
+    assert x == {'a': 'A', 'strategy': {'b1': 'newB1', 'b3': 'B3', 'b11': {}}, 'c': 'C', 'd': 'D'}
 
 
 @pytest.mark.parametrize(('uri', 'humanish'), [