[test](expr opt) Cover narrow decimal cast nullability

fe/fe-core/src/test/java/org/apache/doris/nereids/rules/expression/rules/SimplifyComparisonPredicateTest.java

@@ -1091,6 +1091,24 @@ void testTypeRangeLimitPreservesCastNullability() {
                     ExpressionUtils.trueOrNull(nullableCast));
         }
 
+        SlotReference nonNullableInt = new SlotReference("int_slot", IntegerType.INSTANCE, false);
+        DecimalV3Type narrowDecimal = DecimalV3Type.createDecimalV3Type(2, 0);
+        DecimalV3Literal decimalMin = new DecimalV3Literal(new BigDecimal("-99"));
+        DecimalV3Literal decimalMax = new DecimalV3Literal(new BigDecimal("99"));
+        List<Cast> nullableDecimalCasts = ImmutableList.of(
+                new Cast(nonNullableInt, narrowDecimal),
+                new TryCast(nonNullableInt, narrowDecimal));
+        for (Cast nullableCast : nullableDecimalCasts) {
+            assertRewrite(new LessThanEqual(nullableCast, decimalMax),
+                    ExpressionUtils.trueOrNull(nullableCast));
+            assertRewrite(new GreaterThanEqual(nullableCast, decimalMin),
+                    ExpressionUtils.trueOrNull(nullableCast));
+            assertRewrite(new GreaterThan(nullableCast, decimalMax),
+                    ExpressionUtils.falseOrNull(nullableCast));
+            assertRewrite(new LessThan(nullableCast, decimalMin),
+                    ExpressionUtils.falseOrNull(nullableCast));
+        }
+
         SlotReference nonNullableTinyInt = new SlotReference("tinyint_slot", TinyIntType.INSTANCE, false);
         List<Cast> safeCasts = ImmutableList.of(
                 new Cast(nonNullableTinyInt, SmallIntType.INSTANCE),
@@ -1099,6 +1117,15 @@ void testTypeRangeLimitPreservesCastNullability() {
             assertRewrite(new GreaterThan(safeCast, new SmallIntLiteral((short) 127)),
                     BooleanLiteral.FALSE);
         }
+
+        DecimalV3Type widerDecimal = DecimalV3Type.createDecimalV3Type(3, 0);
+        List<Cast> safeDecimalCasts = ImmutableList.of(
+                new Cast(nonNullableTinyInt, widerDecimal),
+                new TryCast(nonNullableTinyInt, widerDecimal));
+        for (Cast safeCast : safeDecimalCasts) {
+            assertRewrite(new GreaterThan(safeCast, new DecimalV3Literal(new BigDecimal("127"))),
+                    BooleanLiteral.FALSE);
+        }
     }
 
     @Test

regression-test/data/nereids_rules_p0/expression/test_narrow_decimal_cast_nullability.out

@@ -0,0 +1,54 @@
+-- This file is automatically generated. You should know what you did if you want to edit this
+-- !projection_enabled --
+-100	\N	\N	\N	\N	\N	\N	\N	\N
+-99	true	true	false	false	true	true	false	false
+0	true	true	false	false	true	true	false	false
+100	\N	\N	\N	\N	\N	\N	\N	\N
+99	true	true	false	false	true	true	false	false
+
+-- !where_cast_upper_enabled --
+-99
+0
+99
+
+-- !where_cast_lower_enabled --
+-99
+0
+99
+
+-- !where_try_cast_upper_enabled --
+-99
+0
+99
+
+-- !where_try_cast_lower_enabled --
+-99
+0
+99
+
+-- !projection_disabled --
+-100	\N	\N	\N	\N	\N	\N	\N	\N
+-99	true	true	false	false	true	true	false	false
+0	true	true	false	false	true	true	false	false
+100	\N	\N	\N	\N	\N	\N	\N	\N
+99	true	true	false	false	true	true	false	false
+
+-- !where_cast_upper_disabled --
+-99
+0
+99
+
+-- !where_cast_lower_disabled --
+-99
+0
+99
+
+-- !where_try_cast_upper_disabled --
+-99
+0
+99
+
+-- !where_try_cast_lower_disabled --
+-99
+0
+99

regression-test/suites/nereids_rules_p0/expression/test_narrow_decimal_cast_nullability.groovy

@@ -0,0 +1,114 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+suite("test_narrow_decimal_cast_nullability") {
+    sql "drop table if exists narrow_decimal_cast_nullability"
+    sql """
+        create table narrow_decimal_cast_nullability (
+            id int not null
+        ) duplicate key(id)
+        distributed by hash(id) buckets 1
+        properties("replication_num" = "1")
+    """
+    sql "insert into narrow_decimal_cast_nullability values (-100), (-99), (0), (99), (100)"
+
+    sql "set enable_strict_cast = false"
+    sql "set detail_shape_nodes = 'PhysicalProject'"
+    try {
+        explain {
+            sql """
+                shape plan
+                select cast(id as decimalv3(2, 0)) <= 99,
+                       try_cast(id as decimalv3(2, 0)) > 99
+                from narrow_decimal_cast_nullability
+            """
+            contains "OR[( not cast(narrow_decimal_cast_nullability.id as DECIMALV3(2, 0)) IS NULL),NULL]"
+            contains "AND[tryCast(narrow_decimal_cast_nullability.id as DECIMALV3(2, 0)) IS NULL,NULL]"
+        }
+
+        order_qt_projection_enabled """
+            select id,
+                   cast(id as decimalv3(2, 0)) <= 99,
+                   cast(id as decimalv3(2, 0)) >= -99,
+                   cast(id as decimalv3(2, 0)) > 99,
+                   cast(id as decimalv3(2, 0)) < -99,
+                   try_cast(id as decimalv3(2, 0)) <= 99,
+                   try_cast(id as decimalv3(2, 0)) >= -99,
+                   try_cast(id as decimalv3(2, 0)) > 99,
+                   try_cast(id as decimalv3(2, 0)) < -99
+            from narrow_decimal_cast_nullability
+            order by id
+        """
+        order_qt_where_cast_upper_enabled """
+            select id from narrow_decimal_cast_nullability
+            where cast(id as decimalv3(2, 0)) <= 99
+            order by id
+        """
+        order_qt_where_cast_lower_enabled """
+            select id from narrow_decimal_cast_nullability
+            where cast(id as decimalv3(2, 0)) >= -99
+            order by id
+        """
+        order_qt_where_try_cast_upper_enabled """
+            select id from narrow_decimal_cast_nullability
+            where try_cast(id as decimalv3(2, 0)) <= 99
+            order by id
+        """
+        order_qt_where_try_cast_lower_enabled """
+            select id from narrow_decimal_cast_nullability
+            where try_cast(id as decimalv3(2, 0)) >= -99
+            order by id
+        """
+
+        sql "set disable_nereids_expression_rules = 'SIMPLIFY_COMPARISON_PREDICATE'"
+        order_qt_projection_disabled """
+            select id,
+                   cast(id as decimalv3(2, 0)) <= 99,
+                   cast(id as decimalv3(2, 0)) >= -99,
+                   cast(id as decimalv3(2, 0)) > 99,
+                   cast(id as decimalv3(2, 0)) < -99,
+                   try_cast(id as decimalv3(2, 0)) <= 99,
+                   try_cast(id as decimalv3(2, 0)) >= -99,
+                   try_cast(id as decimalv3(2, 0)) > 99,
+                   try_cast(id as decimalv3(2, 0)) < -99
+            from narrow_decimal_cast_nullability
+            order by id
+        """
+        order_qt_where_cast_upper_disabled """
+            select id from narrow_decimal_cast_nullability
+            where cast(id as decimalv3(2, 0)) <= 99
+            order by id
+        """
+        order_qt_where_cast_lower_disabled """
+            select id from narrow_decimal_cast_nullability
+            where cast(id as decimalv3(2, 0)) >= -99
+            order by id
+        """
+        order_qt_where_try_cast_upper_disabled """
+            select id from narrow_decimal_cast_nullability
+            where try_cast(id as decimalv3(2, 0)) <= 99
+            order by id
+        """
+        order_qt_where_try_cast_lower_disabled """
+            select id from narrow_decimal_cast_nullability
+            where try_cast(id as decimalv3(2, 0)) >= -99
+            order by id
+        """
+    } finally {
+        sql "set disable_nereids_expression_rules = ''"
+    }
+}