Refactoring merge Method into a New Class & Adding Unit Tests (#137)

kvmd/yamlconf/merger.py

@@ -0,0 +1,48 @@
+# ========================================================================== #
+#                                                                            #
+#    KVMD - The main PiKVM daemon.                                           #
+#                                                                            #
+#    Copyright (C) 2018-2022  Maxim Devaev <mdevaev@gmail.com>               #
+#                                                                            #
+#    This program is free software: you can redistribute it and/or modify    #
+#    it under the terms of the GNU General Public License as published by    #
+#    the Free Software Foundation, either version 3 of the License, or       #
+#    (at your option) any later version.                                     #
+#                                                                            #
+#    This program is distributed in the hope that it will be useful,         #
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of          #
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           #
+#    GNU General Public License for more details.                            #
+#                                                                            #
+#    You should have received a copy of the GNU General Public License       #
+#    along with this program.  If not, see <https://www.gnu.org/licenses/>.  #
+#                                                                            #
+# ========================================================================== #
+
+from typing import Optional
+
+
+# =====
+def _merge(dest: dict, src: dict) -> None:
+    for key in src:
+        if key in dest:
+            if isinstance(dest[key], dict) and isinstance(src[key], dict):
+                _merge(dest[key], src[key])
+                continue
+        dest[key] = src[key]
+
+
+def yaml_merge(dest: dict, src: dict, source_name: Optional[str]=None) -> None:
+    """ Merges the source dictionary into the destination dictionary. """
+
+    # Checking if destination is None
+    if dest is None:
+        # We can't merge into a None
+        raise ValueError(f"Could not merge {source_name} into None. The destination cannot be None")
+
+    # Checking if source is None or empty
+    if src is None:
+        # If src is None or empty, there's nothing to merge
+        return
+
+    _merge(dest, src)