build: Enable comet tests with spark-4.0 profile

.github/workflows/pr_build.yml

@@ -109,10 +109,8 @@ jobs:
       - name: Java test steps
         uses: ./.github/actions/java-test
         with:
-          # TODO: remove -DskipTests after fixing tests
-          maven_opts: "-Pspark-${{ matrix.spark-version }} -DskipTests"
-          # TODO: upload test reports after enabling tests
-          upload-test-reports: false
+          maven_opts: -Pspark-${{ matrix.spark-version }}
+          upload-test-reports: true
 
   linux-test-with-old-spark:
     strategy:
@@ -237,10 +235,8 @@ jobs:
       - name: Java test steps
         uses: ./.github/actions/java-test
         with:
-          # TODO: remove -DskipTests after fixing tests
-          maven_opts: "-Pspark-${{ matrix.spark-version }} -DskipTests"
-          # TODO: upload test reports after enabling tests
-          upload-test-reports: false
+          maven_opts: -Pspark-${{ matrix.spark-version }}
+          upload-test-reports: true
 
   macos-aarch64-test-with-spark4_0:
     strategy:
@@ -277,10 +273,8 @@ jobs:
       - name: Java test steps
         uses: ./.github/actions/java-test
         with:
-          # TODO: remove -DskipTests after fixing tests
-          maven_opts: "-Pspark-${{ matrix.spark-version }} -DskipTests"
-          # TODO: upload test reports after enabling tests
-          upload-test-reports: false
+          maven_opts: -Pspark-${{ matrix.spark-version }}
+          upload-test-reports: true
 
   macos-aarch64-test-with-old-spark:
     strategy:

common/src/main/scala/org/apache/comet/CometConf.scala

@@ -29,6 +29,8 @@ import org.apache.spark.network.util.JavaUtils
 import org.apache.spark.sql.comet.util.Utils
 import org.apache.spark.sql.internal.SQLConf
 
+import org.apache.comet.shims.ShimCometConf
+
 /**
  * Configurations for a Comet application. Mostly inspired by [[SQLConf]] in Spark.
  *
@@ -41,7 +43,7 @@ import org.apache.spark.sql.internal.SQLConf
  * which retrieves the config value from the thread-local [[SQLConf]] object. Alternatively, you
  * can also explicitly pass a [[SQLConf]] object to the `get` method.
  */
-object CometConf {
+object CometConf extends ShimCometConf {
 
   /** List of all configs that is used for generating documentation */
   val allConfs = new ListBuffer[ConfigEntry[_]]
@@ -361,7 +363,7 @@ object CometConf {
         "column to a long column, a float column to a double column, etc. This is automatically" +
         "enabled when reading from Iceberg tables.")
     .booleanConf
-    .createWithDefault(false)
+    .createWithDefault(COMET_SCHEMA_EVOLUTION_ENABLED_DEFAULT)
 
   val COMET_ROW_TO_COLUMNAR_ENABLED: ConfigEntry[Boolean] =
     conf("spark.comet.rowToColumnar.enabled")
@@ -382,12 +384,13 @@ object CometConf {
       .createWithDefault(Seq("Range,InMemoryTableScan"))
 
   val COMET_ANSI_MODE_ENABLED: ConfigEntry[Boolean] = conf("spark.comet.ansi.enabled")
+    .internal()
     .doc(
       "Comet does not respect ANSI mode in most cases and by default will not accelerate " +
         "queries when ansi mode is enabled. Enable this setting to test Comet's experimental " +
         "support for ANSI mode. This should not be used in production.")
     .booleanConf
-    .createWithDefault(false)
+    .createWithDefault(COMET_ANSI_MODE_ENABLED_DEFAULT)
 
   val COMET_CAST_ALLOW_INCOMPATIBLE: ConfigEntry[Boolean] =
     conf("spark.comet.cast.allowIncompatible")

common/src/main/spark-3.x/org/apache/comet/shims/ShimCometConf.scala

@@ -0,0 +1,25 @@
+/*
+ * 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.
+ */
+
+package org.apache.comet.shims
+
+trait ShimCometConf {
+  protected val COMET_SCHEMA_EVOLUTION_ENABLED_DEFAULT = false
+  protected val COMET_ANSI_MODE_ENABLED_DEFAULT = false
+}

common/src/main/spark-4.0/org/apache/comet/shims/ShimCometConf.scala

@@ -0,0 +1,25 @@
+/*
+ * 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.
+ */
+
+package org.apache.comet.shims
+
+trait ShimCometConf {
+  protected val COMET_SCHEMA_EVOLUTION_ENABLED_DEFAULT = true
+  protected val COMET_ANSI_MODE_ENABLED_DEFAULT = true
+}

docs/source/contributor-guide/development.md

@@ -92,23 +92,27 @@ The plan stability testing framework is located in the `spark` module and can be
 
 ```sh
 ./mvnw -pl spark -Dsuites="org.apache.spark.sql.comet.CometTPCDSV1_4_PlanStabilitySuite" test
+./mvnw -pl spark -Dsuites="org.apache.spark.sql.comet.CometTPCDSV1_4_PlanStabilitySuite" -Pspark-4.0 -nsu test
 ```
 
 and
 ```sh
 ./mvnw -pl spark -Dsuites="org.apache.spark.sql.comet.CometTPCDSV2_7_PlanStabilitySuite" test
+./mvnw -pl spark -Dsuites="org.apache.spark.sql.comet.CometTPCDSV2_7_PlanStabilitySuite" -Pspark-4.0 -nsu test
 ```
 
 If your pull request changes the query plans generated by Comet, you should regenerate the golden files.
 To regenerate the golden files, you can run the following command:
 
 ```sh
 SPARK_GENERATE_GOLDEN_FILES=1 ./mvnw -pl spark -Dsuites="org.apache.spark.sql.comet.CometTPCDSV1_4_PlanStabilitySuite" test
+SPARK_GENERATE_GOLDEN_FILES=1 ./mvnw -pl spark -Dsuites="org.apache.spark.sql.comet.CometTPCDSV1_4_PlanStabilitySuite" -Pspark-4.0 -nsu test
 ```
 
 and
 ```sh
 SPARK_GENERATE_GOLDEN_FILES=1 ./mvnw -pl spark -Dsuites="org.apache.spark.sql.comet.CometTPCDSV2_7_PlanStabilitySuite" test
+SPARK_GENERATE_GOLDEN_FILES=1 ./mvnw -pl spark -Dsuites="org.apache.spark.sql.comet.CometTPCDSV2_7_PlanStabilitySuite" -Pspark-4.0 -nsu test
 ```
 
 ## Benchmark

docs/source/user-guide/configs.md

@@ -23,7 +23,6 @@ Comet provides the following configuration settings.
 
 | Config | Description | Default Value |
 |--------|-------------|---------------|
-| spark.comet.ansi.enabled | Comet does not respect ANSI mode in most cases and by default will not accelerate queries when ansi mode is enabled. Enable this setting to test Comet's experimental support for ANSI mode. This should not be used in production. | false |
 | spark.comet.batchSize | The columnar batch size, i.e., the maximum number of rows that a batch can contain. | 8192 |
 | spark.comet.cast.allowIncompatible | Comet is not currently fully compatible with Spark for all cast operations. Set this config to true to allow them anyway. See compatibility guide for more information. | false |
 | spark.comet.columnar.shuffle.async.enabled | Whether to enable asynchronous shuffle for Arrow-based shuffle. By default, this config is false. | false |

spark/src/main/scala/org/apache/comet/CometSparkSessionExtensions.scala

@@ -1030,6 +1030,10 @@ object CometSparkSessionExtensions extends Logging {
     org.apache.spark.SPARK_VERSION >= "3.4"
   }
 
+  def isSpark40Plus: Boolean = {
+    org.apache.spark.SPARK_VERSION >= "4.0"
+  }
+
   /** Calculates required memory overhead in MB per executor process for Comet. */
   def getCometMemoryOverheadInMiB(sparkConf: SparkConf): Long = {
     // `spark.executor.memory` default value is 1g

spark/src/main/scala/org/apache/comet/serde/QueryPlanSerde.scala

@@ -2201,7 +2201,8 @@ object QueryPlanSerde extends Logging with ShimQueryPlanSerde with CometExprShim
   }
 
   def nullIfWhenPrimitive(expression: Expression): Expression = if (isPrimitive(expression)) {
-    new NullIf(expression, Literal.default(expression.dataType)).child
+    val zero = Literal.default(expression.dataType)
+    If(EqualTo(expression, zero), Literal.create(null, expression.dataType), expression)
   } else {
     expression
   }