Fix infix operators and filter expression literals

Author: jg-rp

CHANGELOG.md

@@ -4,7 +4,7 @@
 
 **Fixes**
 
-- Fixed handling of JSONPath literals in filter expressions. We now raise a `JSONPathSyntaxError` if a filter expression literal is not part of a comparison or function expression. See [jsonpath-compliance-test-suite#81](https://github.com/jsonpath-standard/jsonpath-compliance-test-suite/pull/81).
+- Fixed handling of JSONPath literals in filter expressions. We now raise a `JSONPathSyntaxError` if a filter expression literal is not part of a comparison, membership or function expression. See [jsonpath-compliance-test-suite#81](https://github.com/jsonpath-standard/jsonpath-compliance-test-suite/pull/81).
 
 **Features**
 

jsonpath/parse.py

@@ -197,6 +197,22 @@ class Parser:
         ]
     )
 
+    # Infix operators that accept filter expression literals.
+    INFIX_LITERAL_OPERATORS = frozenset(
+        [
+            "==",
+            ">=",
+            ">",
+            "<=",
+            "<",
+            "!=",
+            "<>",
+            "=~",
+            "in",
+            "contains",
+        ]
+    )
+
     PREFIX_OPERATORS = frozenset(
         [
             TOKEN_NOT,
@@ -530,14 +546,14 @@ def parse_infix_expression(
             self._raise_for_non_comparable_function(left, tok)
             self._raise_for_non_comparable_function(right, tok)
 
-        if operator not in self.COMPARISON_OPERATORS:
-            if isinstance(left, Literal):
+        if operator not in self.INFIX_LITERAL_OPERATORS:
+            if isinstance(left, (Literal, Nil)):
                 raise JSONPathSyntaxError(
                     "filter expression literals outside of "
                     "function expressions must be compared",
                     token=tok,
                 )
-            if isinstance(right, Literal):
+            if isinstance(right, (Literal, Nil)):
                 raise JSONPathSyntaxError(
                     "filter expression literals outside of "
                     "function expressions must be compared",

tests/test_find.py

@@ -87,6 +87,26 @@ class Case:
         data=[{"a": True, "b": False}],
         want=[{"a": True, "b": False}],
     ),
+    Case(
+        description="array contains literal",
+        path="$[[email protected] contains 'foo']",
+        data=[{"a": ["foo", "bar"]}, {"a": ["bar"]}],
+        want=[
+            {
+                "a": ["foo", "bar"],
+            }
+        ],
+    ),
+    Case(
+        description="literal in array",
+        path="$[?'foo' in @.a]",
+        data=[{"a": ["foo", "bar"]}, {"a": ["bar"]}],
+        want=[
+            {
+                "a": ["foo", "bar"],
+            }
+        ],
+    ),
 ]