[SPARK-33292][SQL] Make Literal ArrayBasedMapData string representation disambiguous

Author: dongjoon-hyun

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

@@ -297,6 +297,7 @@ case class Literal (value: Any, dataType: DataType) extends LeafExpression {
   override def toString: String = value match {
     case null => "null"
     case binary: Array[Byte] => s"0x" + DatatypeConverter.printHexBinary(binary)
+    case d: ArrayBasedMapData => s"map(${d.toString})"
     case other => other.toString
   }
 

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/LiteralExpressionSuite.scala

@@ -209,6 +209,7 @@ class LiteralExpressionSuite extends SparkFunSuite with ExpressionEvalHelper {
     }
     checkMapLiteral(Map("a" -> 1, "b" -> 2, "c" -> 3))
     checkMapLiteral(Map("1" -> 1.0, "2" -> 2.0, "3" -> 3.0))
+    assert(Literal.create(Map("a" -> 1)).toString === "map(keys: [a], values: [1])")
   }
 
   test("struct") {