Introduce nested version syntax

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 <!-- Please add changes under the Unreleased section that reads 'No current changes' otherwise -->
 
+# v2.9.1
+
+- New nested version syntax `~nested:version`
+
 # v2.9.0
 
 - Resolve @-directives relative to `_machinable` module rather than top project level

src/machinable/config/interface.py

@@ -13,7 +13,7 @@
 from .parser import parse_mixins
 
 
-def collect_updates(version):
+def _collect_updates(version):
     collection = []
     for update in version:
         arguments = update["arguments"]
@@ -42,7 +42,7 @@ def __init__(self, parsed_config, version=None, default_class=None):
         self.default_class = default_class
         self.schema_validation = get_settings()["schema_validation"]
 
-    def _get_version(self, name, config, current=None):
+    def _get_version(self, name, config):
         # from yaml file
         if name.endswith(".yaml") or name.endswith(".json"):
             with open(name) as f:
@@ -63,24 +63,22 @@ def _get_version(self, name, config, current=None):
             return yaml.load(name, Loader=yaml.FullLoader)
 
         # from local version
-        if name in config:
-            version = copy.deepcopy(config[name])
-            if not current:
-                return version
-            else:
-                # nested lookup
-                try:
-                    return update_dict(copy.deepcopy(current[name]), version)
-                except KeyError:
-                    return version
-
-        if current:
-            # nested lookup
-            try:
-                return copy.deepcopy(current[name])
-            except KeyError:
-                # ignore non-existing nested lookups
-                return {}
+        version = {}
+        path = name[1:].split(":")
+        level = config
+        try:
+            for key in path:
+                level = level["~" + key]
+                # extract config on this level
+                u = {
+                    k: copy.deepcopy(v)
+                    for k, v in level.items()
+                    if not k.startswith("~")
+                }
+                version = update_dict(version, u)
+            return version
+        except KeyError:
+            pass
 
         raise KeyError(
             f"Version '{name}' could not be found.\n"
@@ -252,8 +250,7 @@ def get_component(self, name, version=None, flags=None):
             versions.append({"arguments": {"components": copy.deepcopy(version)}})
 
         version = {}
-        for updates in collect_updates(versions):
-            # select components/node subsection
+        for updates in _collect_updates(versions):
             update = updates.get("components", None)
             if update is None:
                 continue
@@ -267,7 +264,7 @@ def get_component(self, name, version=None, flags=None):
                 # load arguments from machinable.yaml
                 if isinstance(k, str):
                     config["versions"].append(k)
-                    k = self._get_version(k, config["args"], version)
+                    k = self._get_version(k, config["args"])
                 elif isinstance(k, dict):
                     # evaluate computed properties
                     for key in k.keys():
@@ -287,7 +284,7 @@ def get_component(self, name, version=None, flags=None):
 
         # remove unused versions
         config["args"] = {
-            k: v if not k.startswith("~") else "_"
+            k: v if not k.startswith("~") else ":"
             for k, v in config["args"].items()
             if not k.startswith("~") or k in config["versions"]
         }

tests/config/config_interface_test.py

@@ -69,23 +69,24 @@ def test_config_versioning():
     assert e["beta"]["test"]
 
     # nested
-    t = Experiment().components(("thenode", ("~three", "~nested")))
+    t = Experiment().components(("thenode", "~three:nested"))
     e, m = to_config(test_project, t)
-    assert e["works"]
-    assert e["nested"]
+    assert e["unaffected"] == "value"
+    assert e["nested"] is None
     assert e["alpha"] == 4
     assert e["beta"] == "nested"
+    assert "should_not_be" not in e
 
     t = Experiment().components(("thenode", ("~two", "~nested")))
     e, m = to_config(test_project, t)
     assert e["alpha"] == 2
-    assert e["nested"]
+    assert e["nested"] is True
 
-    t = Experiment().components(("thenode", ("~three", "~nested", "~nestednested")))
+    t = Experiment().components(("thenode", ("~three:nested:nestednested")))
     e, m = to_config(test_project, t)
-    assert e["works"]
+    assert e["unaffected"] == "value"
+    assert e["works"] is False
     assert e["alpha"] == 5
-    assert e["q"] == -1
     assert e["beta"] == "overwritten"
     assert e["added"] == "value"
 

tests/test_project/machinable.yaml

@@ -28,6 +28,7 @@ components:
       works:
       nested:
       added:
+      unaffected: true
       q:
       key:
         mixing:
@@ -42,6 +43,7 @@ components:
         alpha: 2
       ~three:
         alpha: 3
+        unaffected: value
         ~nested:
           works: False
           alpha: 4
@@ -50,8 +52,8 @@ components:
             beta: overwritten
             alpha: 5
             added: value
-      ~nestednested:
-        q: -1
+        ~second_nested:
+          should_not_be: selected
       ~nested:
         nested: True
         works: True