Enable back testcases in CalciteWindowQueryTest (#15045)

Most of the testcases were disabled in CalciteWindowQueryTest during the Calcite-1.35 upgrade; there were some changes arising from the fact that the removal of DRUID_SUM had some unexpected sideffects:

SqlStdOperatorTable.SUM became the SUM operator
because of that SqlToRelConverter started rewriting windowed SUM -s into SUM0 -s
my opinion is that w.r.t to Druid this rewrite provides no real advantage - as SUM0 is serviced by SUM here
I believe that's not 100% correct in cases when it aggregates just null-s but that doesnt matter in this case
I propose to introduce back a local DRUID_SUM thing as an unchanged SUM and later when CALCITE-6020 is fixed ; we can drop that.

sql/src/main/java/org/apache/druid/sql/calcite/aggregation/builtin/SumSqlAggregator.java

@@ -19,9 +19,10 @@
 
 package org.apache.druid.sql.calcite.aggregation.builtin;
 
+import org.apache.calcite.linq4j.Nullness;
 import org.apache.calcite.rel.core.AggregateCall;
 import org.apache.calcite.sql.SqlAggFunction;
-import org.apache.calcite.sql.fun.SqlStdOperatorTable;
+import org.apache.calcite.sql.fun.SqlSumAggFunction;
 import org.apache.druid.math.expr.ExprMacroTable;
 import org.apache.druid.query.aggregation.AggregatorFactory;
 import org.apache.druid.query.aggregation.DoubleSumAggregatorFactory;
@@ -35,11 +36,17 @@ import javax.annotation.Nullable;
 
 public class SumSqlAggregator extends SimpleSqlAggregator
 {
+  /**
+   * We use this custom aggregation function instead of builtin SqlStdOperatorTable.SUM
+   * to avoid transformation to COUNT+SUM0. See CALCITE-6020 for more details.
+   * It can be handled differently after CALCITE-6020 is addressed.
+   */
+  private static final SqlAggFunction DRUID_SUM = new SqlSumAggFunction(Nullness.castNonNull(null)) {};
 
   @Override
   public SqlAggFunction calciteFunction()
   {
-    return SqlStdOperatorTable.SUM;
+    return DRUID_SUM;
   }
 
   @Override

sql/src/test/java/org/apache/druid/sql/calcite/CalciteWindowQueryTest.java

@@ -28,11 +28,15 @@ import org.apache.druid.common.config.NullHandling;
 import org.apache.druid.jackson.DefaultObjectMapper;
 import org.apache.druid.java.util.common.ISE;
 import org.apache.druid.java.util.common.RE;
+import org.apache.druid.query.Query;
+import org.apache.druid.query.QueryContexts;
 import org.apache.druid.query.operator.OperatorFactory;
 import org.apache.druid.query.operator.WindowOperatorQuery;
 import org.apache.druid.segment.column.ColumnType;
 import org.apache.druid.segment.column.RowSignature;
+import org.apache.druid.sql.calcite.CalciteWindowQueryTest.WindowQueryTestInputClass.TestType;
 import org.apache.druid.sql.calcite.planner.PlannerContext;
+import org.hamcrest.Matchers;
 import org.junit.Assert;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -47,6 +51,10 @@ import java.util.Locale;
 import java.util.Objects;
 import java.util.function.Function;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assume.assumeThat;
+
 /**
  * These tests are file-based, look in resources -> calcite/tests/window for the set of test specifications.
  */
@@ -116,15 +124,14 @@ public class CalciteWindowQueryTest extends BaseCalciteQueryTest
       }
     };
 
-    if ("failingTest".equals(input.type)) {
-      return;
-    }
+    assumeThat(input.type, Matchers.not(TestType.failingTest));
 
-    if ("operatorValidation".equals(input.type)) {
+    if (input.type == TestType.operatorValidation) {
       testBuilder()
           .skipVectorize(true)
           .sql(input.sql)
-          .queryContext(ImmutableMap.of(PlannerContext.CTX_ENABLE_WINDOW_FNS, true))
+          .queryContext(ImmutableMap.of(PlannerContext.CTX_ENABLE_WINDOW_FNS, true,
+              QueryContexts.ENABLE_DEBUG, true))
           .addCustomVerification(QueryVerification.ofResults(results -> {
             if (results.exception != null) {
               throw new RE(results.exception, "Failed to execute because of exception.");
@@ -140,7 +147,7 @@ public class CalciteWindowQueryTest extends BaseCalciteQueryTest
             // and aggregations=[CountAggregatorFactory{name='w0'}, LongSumAggregatorFactory{fieldName='a0', expression='null', name='w1'}]}}]}
             // These 2 tests are marked as failingTests to unblock testing at this moment
 
-            final WindowOperatorQuery query = (WindowOperatorQuery) results.recordedQueries.get(0);
+            final WindowOperatorQuery query = getWindowOperatorQuery(results.recordedQueries);
             for (int i = 0; i < input.expectedOperators.size(); ++i) {
               final OperatorFactory expectedOperator = input.expectedOperators.get(i);
               final OperatorFactory actualOperator = query.getOperators().get(i);
@@ -199,6 +206,14 @@ public class CalciteWindowQueryTest extends BaseCalciteQueryTest
     }
   }
 
+  private WindowOperatorQuery getWindowOperatorQuery(List<Query<?>> queries)
+  {
+    assertEquals(1, queries.size());
+    Object query = queries.get(0);
+    assertTrue(query instanceof WindowOperatorQuery);
+    return (WindowOperatorQuery) query;
+  }
+
   private void maybeDumpActualResults(
       Function<Object, String> toStrFn, List<Object[]> results
   )
@@ -212,8 +227,13 @@ public class CalciteWindowQueryTest extends BaseCalciteQueryTest
 
   public static class WindowQueryTestInputClass
   {
+    enum TestType
+    {
+      failingTest,
+      operatorValidation
+    }
     @JsonProperty
-    public String type;
+    public TestType type;
 
     @JsonProperty
     public String sql;

sql/src/test/resources/calcite/tests/window/simpleSum.sqlTest

@@ -1,4 +1,4 @@
-type: "failingTest"
+type: "operatorValidation"
 
 sql: |
   SELECT

sql/src/test/resources/calcite/tests/window/wikipediaAggregationsMultipleOrdering.sqlTest

@@ -1,4 +1,4 @@
-type: "failingTest"
+type: "operatorValidation"
 
 sql: |
     SELECT

sql/src/test/resources/calcite/tests/window/wikipediaCumulativeOrdered.sqlTest

@@ -1,4 +1,4 @@
-type: "failingTest"
+type: "operatorValidation"
 
 sql: |
   SELECT

sql/src/test/resources/calcite/tests/window/wikipediaFramedAggregations.sqlTest

@@ -1,4 +1,4 @@
-type: "failingTest"
+type: "operatorValidation"
 
 sql: |
     SELECT

sql/src/test/resources/calcite/tests/window/wikipediaSimplePartition.sqlTest

@@ -1,4 +1,4 @@
-type: "failingTest"
+type: "operatorValidation"
 
 sql: |
   SELECT

sql/src/test/resources/calcite/tests/window/wikipediaSimplePartitionInitialSort.sqlTest

@@ -1,4 +1,4 @@
-type: "failingTest"
+type: "operatorValidation"
 
 # Like wikipediaSimplePartition, but requires re-sorting the input data because the order of the GROUP BY
 # does not match the required order for window partitioning. ("t" and "countryIsoCode" are flipped.)