address comments

Author: kenrickyap

core/src/test/java/org/opensearch/sql/expression/json/JsonFunctionsTest.java

@@ -290,10 +290,12 @@ void json_extract_throws_SemanticCheckException() {
                         DSL.literal(new ExprStringValue("{\"invalid\":\"json\", \"string\"}")),
                         DSL.literal(new ExprStringValue("$.a")))
                     .valueOf());
-    assertEquals(
-        "JSON string '\"{\"invalid\":\"json\", \"string\"}\"' is not valid. Error details:"
-            + " net.minidev.json.parser.ParseException: Unexpected character (}) at position 26.",
-        invalidJsonError.getMessage());
+    assertTrue(
+        invalidJsonError
+            .getMessage()
+            .startsWith(
+                "JSON string '\"{\"invalid\":\"json\", \"string\"}\"' is not valid. Error"
+                    + " details:"));
   }
 
   @Test

docs/user/ppl/functions/json.rst

@@ -75,8 +75,8 @@ Argument type: STRING, STRING
 
 Return type: STRING/BOOLEAN/DOUBLE/INTEGER/NULL/STRUCT/ARRAY
 
-- Returns a JSON array if path points to multiple results (e.g. $.a[*]) or if the path points to an array.
-- Return null if path is not valid is MISSING or NULL.
+- Returns a JSON array if `path` points to multiple results (e.g. $.a[*]) or if the `path` points to an array.
+- Return null if `path` is not valid, or if JSON `doc` is MISSING or NULL.
 - Throws SemanticCheckException if `doc` or `path` is malformed.
 - Throws ExpressionEvaluationException if `path` is missing.