fix(yaml): Better preserve YAML formatting

Updated the YAML editing code to work around an issue where blank lines
and multi-line comments weren't handled correctly, resulting in blank
lines getting deleted and new blank lines getting inserted in comments.

Also changed the default indentation to match what is used in the ZMK
config template, and enabled preserving quotes by default.

Author: joelspadin

zmk/yaml.py

@@ -18,6 +18,22 @@ class YAML(ruamel.yaml.YAML):
     readable or seekable, a leading comment will be overwritten.
     """
 
+    def __init__(self, *args, **kwargs) -> None:
+        super().__init__(*args, **kwargs)
+
+        self.preserve_quotes = True
+        self.indent(mapping=2, sequence=4, offset=2)
+
+    def load(self, stream: Path | IO | str) -> Any:
+        # Reading from a Path causes a round-trip conversion to drop blank lines
+        # for some reason. As a workaround, just read in the whole file to a
+        # string and parse that. It's probably slower, but none of the file we
+        # work with are large enough for it to matter.
+        if isinstance(stream, Path):
+            return super().load(stream.read_text())
+
+        return super().load(stream)
+
     def dump(self, data, stream: Path | IO | None = None, *, transform=None) -> None:
         if stream is None:
             raise TypeError("Dumping from a context manager is not supported.")