[SPARK-57517][SQL] Fix schema_of_json to return proper error on non-string literal input

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/jsonExpressions.scala

@@ -454,23 +454,28 @@ case class SchemaOfJson(
 
   override def nullable: Boolean = false
 
-  @transient
-  private lazy val json = child.eval().asInstanceOf[UTF8String]
-
   override def checkInputDataTypes(): TypeCheckResult = {
-    if (child.foldable && json != null) {
-      super.checkInputDataTypes()
-    } else if (!child.foldable) {
+    if (!child.foldable) {
       DataTypeMismatch(
         errorSubClass = "NON_FOLDABLE_INPUT",
         messageParameters = Map(
           "inputName" -> toSQLId("json"),
           "inputType" -> toSQLType(child.dataType),
           "inputExpr" -> toSQLExpr(child)))
-    } else {
+    } else if (child.eval() == null) {
       DataTypeMismatch(
         errorSubClass = "UNEXPECTED_NULL",
         messageParameters = Map("exprName" -> "json"))
+    } else if (child.dataType != StringType) {
+      DataTypeMismatch(
+        errorSubClass = "UNEXPECTED_INPUT_TYPE",
+        messageParameters = Map(
+          "paramIndex" -> ordinalNumber(0),
+          "inputSql" -> toSQLExpr(child),
+          "inputType" -> toSQLType(child.dataType),
+          "requiredType" -> toSQLType(StringType)))
+    } else {
+      super.checkInputDataTypes()
     }
   }
 

sql/core/src/test/resources/sql-tests/analyzer-results/json-functions.sql.out

@@ -446,6 +446,30 @@ org.apache.spark.sql.catalyst.ExtendedAnalysisException
 }
 
 
+-- !query
+select schema_of_json(42)
+-- !query analysis
+org.apache.spark.sql.catalyst.ExtendedAnalysisException
+{
+  "errorClass" : "DATATYPE_MISMATCH.UNEXPECTED_INPUT_TYPE",
+  "sqlState" : "42K09",
+  "messageParameters" : {
+    "inputSql" : "\"42\"",
+    "inputType" : "\"INT\"",
+    "paramIndex" : "first",
+    "requiredType" : "\"STRING\"",
+    "sqlExpr" : "\"schema_of_json(42)\""
+  },
+  "queryContext" : [ {
+    "objectType" : "",
+    "objectName" : "",
+    "startIndex" : 8,
+    "stopIndex" : 25,
+    "fragment" : "schema_of_json(42)"
+  } ]
+}
+
+
 -- !query
 CREATE TEMPORARY VIEW jsonTable(jsonField, a) AS SELECT * FROM VALUES ('{"a": 1, "b": 2}', 'a')
 -- !query analysis

sql/core/src/test/resources/sql-tests/inputs/json-functions.sql

@@ -75,6 +75,7 @@ select to_json(array(array(1, 2, 3), array(4)));
 select schema_of_json('{"c1":1}', map('primitivesAsString', 'true'));
 select schema_of_json('{"c1":01, "c2":0.1}', map('allowNumericLeadingZeros', 'true', 'prefersDecimal', 'true'));
 select schema_of_json(null);
+select schema_of_json(42);
 CREATE TEMPORARY VIEW jsonTable(jsonField, a) AS SELECT * FROM VALUES ('{"a": 1, "b": 2}', 'a');
 SELECT schema_of_json(jsonField) FROM jsonTable;
 

sql/core/src/test/resources/sql-tests/results/json-functions.sql.out

@@ -496,6 +496,32 @@ org.apache.spark.sql.catalyst.ExtendedAnalysisException
 }
 
 
+-- !query
+select schema_of_json(42)
+-- !query schema
+struct<>
+-- !query output
+org.apache.spark.sql.catalyst.ExtendedAnalysisException
+{
+  "errorClass" : "DATATYPE_MISMATCH.UNEXPECTED_INPUT_TYPE",
+  "sqlState" : "42K09",
+  "messageParameters" : {
+    "inputSql" : "\"42\"",
+    "inputType" : "\"INT\"",
+    "paramIndex" : "first",
+    "requiredType" : "\"STRING\"",
+    "sqlExpr" : "\"schema_of_json(42)\""
+  },
+  "queryContext" : [ {
+    "objectType" : "",
+    "objectName" : "",
+    "startIndex" : 8,
+    "stopIndex" : 25,
+    "fragment" : "schema_of_json(42)"
+  } ]
+}
+
+
 -- !query
 CREATE TEMPORARY VIEW jsonTable(jsonField, a) AS SELECT * FROM VALUES ('{"a": 1, "b": 2}', 'a')
 -- !query schema