serde/fix: round trip string sanitizing

pkgs/clan-cli/clan_cli/api/serde.py

@@ -155,13 +155,12 @@ def construct_value(
 
         return Path(field_value)
 
-    # Trivial values
     if t is str:
         if not isinstance(field_value, str):
             msg = f"Expected string, got {field_value}"
             raise ClanError(msg, location=f"{loc}")
 
-        return field_value
+        return json.loads(f'"{field_value}"')
 
     if t is int and not isinstance(field_value, str):
         return int(field_value)  # type: ignore

pkgs/clan-cli/tests/test_deserializers.py

@@ -265,6 +265,18 @@ def test_none_or_string() -> None:
     assert checked3 is None
 
 
+def test_roundtrip_escape() -> None:
+    assert from_dict(str, "\\n") == "\n"
+    assert dataclass_to_dict("\n") == "\\n"
+
+    # Test that the functions are inverses of each other
+    # f(g(x)) == x
+    # and
+    # g(f(x)) == x
+    assert from_dict(str, dataclass_to_dict("\n")) == "\n"
+    assert dataclass_to_dict(from_dict(str, "\\n")) == "\\n"
+
+
 def test_path_field() -> None:
     @dataclass
     class Person: