Implement __str__ for the current key identifier

Author: jg-rp

jsonpath/filter.py

@@ -668,6 +668,9 @@ def __init__(self) -> None:
         super().__init__()
         self.volatile = True
 
+    def __str__(self) -> str:
+        return "#"
+
     def __eq__(self, other: object) -> bool:
         return isinstance(other, CurrentKey)
 

tests/test_parse.py

@@ -170,6 +170,11 @@ class Case:
         path="$.some.~",
         want="$['some'][~]",
     ),
+    Case(
+        description="current key identifier",
+        path="$[?# > 2]",
+        want="$[?# > 2]",
+    ),
     Case(
         description="comparison to single quoted string literal with escape",
         path="$[[email protected] == 'ba\\'r']",