Update the code for feedback of code review

Author: chenghao-intel

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/Optimizer.scala

@@ -134,15 +134,13 @@ object NullPropagation extends Rule[LogicalPlan] {
         case Literal(null, _) => Literal(null, e.dataType)
         case _ => e
       }
-      case e: And => e // leave it for BooleanSimplification
-      case e: Or => e  // leave it for BooleanSimplification
-      // Put exceptional cases above
+      // Put exceptional cases above if any
       case e: BinaryArithmetic => e.children match {
         case Literal(null, _) :: right :: Nil => Literal(null, e.dataType)
         case left :: Literal(null, _) :: Nil => Literal(null, e.dataType)
         case _ => e
       }
-      case e: BinaryPredicate => e.children match {
+      case e: BinaryComparison => e.children match {
         case Literal(null, _) :: right :: Nil => Literal(null, e.dataType)
         case left :: Literal(null, _) :: Nil => Literal(null, e.dataType)
         case _ => e

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

@@ -250,17 +250,17 @@ class ExpressionEvaluationSuite extends FunSuite {
 
     intercept[Exception] {evaluate(Literal(1) cast BinaryType, null)}
 
-    checkEvaluation(("abcdef" cast StringType).nullable, false)
-    checkEvaluation(("abcdef" cast BinaryType).nullable,false)
-    checkEvaluation(("abcdef" cast BooleanType).nullable, false)
-    checkEvaluation(("abcdef" cast TimestampType).nullable, true)
-    checkEvaluation(("abcdef" cast LongType).nullable, true)
-    checkEvaluation(("abcdef" cast IntegerType).nullable, true)
-    checkEvaluation(("abcdef" cast ShortType).nullable, true)
-    checkEvaluation(("abcdef" cast ByteType).nullable, true)
-    checkEvaluation(("abcdef" cast DecimalType).nullable, true)
-    checkEvaluation(("abcdef" cast DoubleType).nullable, true)
-    checkEvaluation(("abcdef" cast FloatType).nullable, true)
+    assert(("abcdef" cast StringType).nullable === false)
+    assert(("abcdef" cast BinaryType).nullable === false)
+    assert(("abcdef" cast BooleanType).nullable === false)
+    assert(("abcdef" cast TimestampType).nullable === true)
+    assert(("abcdef" cast LongType).nullable === true)
+    assert(("abcdef" cast IntegerType).nullable === true)
+    assert(("abcdef" cast ShortType).nullable === true)
+    assert(("abcdef" cast ByteType).nullable === true)
+    assert(("abcdef" cast DecimalType).nullable === true)
+    assert(("abcdef" cast DoubleType).nullable === true)
+    assert(("abcdef" cast FloatType).nullable === true)
 
     checkEvaluation(Cast(Literal(null, IntegerType), ShortType), null)
   }