refactor recursive code

jrnl/override.py

@@ -10,7 +10,7 @@ def apply_overrides(overrides: dict, base_config: dict) -> dict:
 def recursively_apply(config: dict, nodes: list, override_value) -> dict:
     """Recurse through configuration and apply overrides at the leaf of the config tree
 
-    See: https://stackoverflow.com/a/47276490 for algorithm
+    Credit to iJames on SO: https://stackoverflow.com/a/47276490 for algorithm
 
     Args:
         config (dict): loaded configuration from YAML
@@ -18,11 +18,18 @@ def recursively_apply(config: dict, nodes: list, override_value) -> dict:
         override_value (str): runtime override passed from the command-line
     """
     key = nodes[0]
-    config[key] = (
-        override_value
-        if len(nodes) == 1
-        else recursively_apply(
-            config[key] if key in config else {}, nodes[1:], override_value
-        )
-    )
+    if len(nodes) == 1:
+        config[key] = override_value
+    else:
+        next_key = nodes[1:]
+        _recursively_apply(_get_config_node(config, key), next_key, override_value)
+
     return config
+
+
+def _get_config_node(config: dict, key: str):
+    if key in config:
+        pass
+    else:
+        config[key] = None
+    return config[key]

tests/test_override.py

@@ -32,3 +32,9 @@ def test_recursive_override(minimal_config):
     cfg = {"colors": {"body": "red", "title": "green"}}
     cfg = recursively_apply(cfg, ["colors", "body"], "blue")
     assert cfg["colors"]["body"] == "blue"
+
+
+def test_get_config_node(minimal_config):
+    assert len(minimal_config.keys()) == 3
+    assert _get_config_node(minimal_config, "editor") == "vim"
+    assert _get_config_node(minimal_config, "display_format") == None