add CsvTests

Author: fang-xing-esql

x-pack/plugin/esql/qa/testFixtures/src/main/resources/bucket.csv-spec

@@ -850,3 +850,37 @@ c:long | b:date
 11     | 1984-05-01T00:00:00.000Z
 11     | 1991-01-01T00:00:00.000Z
 ;
+
+resolveGroupingsBeforeResolvingImplicitReferencesToGroupings
+required_capability: resolve_groupings_before_resolving_references_to_groupings_in_aggregations
+
+FROM employees
+| STATS c = count(emp_no), b = BUCKET(hire_date, "1 year") + 1 year BY yr = BUCKET(hire_date, "1 year")
+| SORT yr
+| LIMIT 5
+;
+
+c:long | b:datetime               | yr:datetime
+11     | 1986-01-01T00:00:00.000Z | 1985-01-01T00:00:00.000Z
+11     | 1987-01-01T00:00:00.000Z | 1986-01-01T00:00:00.000Z
+15     | 1988-01-01T00:00:00.000Z | 1987-01-01T00:00:00.000Z
+9      | 1989-01-01T00:00:00.000Z | 1988-01-01T00:00:00.000Z
+13     | 1990-01-01T00:00:00.000Z | 1989-01-01T00:00:00.000Z
+;
+
+resolveGroupingsBeforeResolvingExplicitReferencesToGroupings
+required_capability: resolve_groupings_before_resolving_references_to_groupings_in_aggregations
+
+FROM employees
+| STATS c = count(emp_no), b = yr + 1 year BY yr = BUCKET(hire_date, "1 year")
+| SORT yr
+| LIMIT 5
+;
+
+c:long | b:datetime               | yr:datetime
+11     | 1986-01-01T00:00:00.000Z | 1985-01-01T00:00:00.000Z
+11     | 1987-01-01T00:00:00.000Z | 1986-01-01T00:00:00.000Z
+15     | 1988-01-01T00:00:00.000Z | 1987-01-01T00:00:00.000Z
+9      | 1989-01-01T00:00:00.000Z | 1988-01-01T00:00:00.000Z
+13     | 1990-01-01T00:00:00.000Z | 1989-01-01T00:00:00.000Z
+;

x-pack/plugin/esql/qa/testFixtures/src/main/resources/stats.csv-spec

@@ -3097,3 +3097,27 @@ ROW a = [1,2,3], b = 5
 STD_DEV(a):double | STD_DEV(b):double
 0.816496580927726 | 0.0
 ;
+
+resolveGroupingsBeforeResolvingImplicitReferencesToGroupings
+required_capability: resolve_groupings_before_resolving_references_to_groupings_in_aggregations
+
+FROM employees
+| EVAL date = "2025-01-01"::datetime
+| stats m = MAX(hire_date) BY d = (date == "2025-01-01")
+;
+
+m:datetime               | d:boolean
+1999-04-30T00:00:00.000Z | true
+;
+
+resolveGroupingsBeforeResolvingExplicitReferencesToGroupings
+required_capability: resolve_groupings_before_resolving_references_to_groupings_in_aggregations
+
+FROM employees
+| EVAL date = "2025-01-01"::datetime
+| stats m = MAX(hire_date), x = d::int + 1 BY d = (date == "2025-01-01")
+;
+
+m:datetime               | x:integer | d:boolean
+1999-04-30T00:00:00.000Z | 2         | true
+;

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/action/EsqlCapabilities.java

@@ -1049,7 +1049,12 @@ public enum Cap {
         /**
          * The {@code _query} API now gives a cast recommendation if multiple types are found in certain instances.
          */
-        SUGGESTED_CAST;
+        SUGGESTED_CAST,
+
+        /**
+         * Resolve groupings before resolving references to groupings in the aggregations.
+         */
+        RESOLVE_GROUPINGS_BEFORE_RESOLVING_REFERENCES_TO_GROUPINGS_IN_AGGREGATIONS;
 
         private final boolean enabled;
 

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/analysis/Analyzer.java

@@ -591,9 +591,9 @@ private Aggregate resolveAggregate(Aggregate aggregate, List<Attribute> children
                 boolean groupingResolved = Resolvables.resolved(groupings);
                 int size = groupingResolved ? aggregates.size() : aggregates.size() - groupings.size();
                 for (int i = 0; i < aggregates.size(); i++) {
-                    NamedExpression agg = aggregates.get(i);
+                    NamedExpression maybeResolvedAgg = aggregates.get(i);
                     if (i < size) { // Skip resolving references to groupings in the aggregations if the groupings are not resolved yet.
-                        agg = (NamedExpression) agg.transformUp(UnresolvedAttribute.class, ua -> {
+                        maybeResolvedAgg = (NamedExpression) maybeResolvedAgg.transformUp(UnresolvedAttribute.class, ua -> {
                             Expression ne = ua;
                             Attribute maybeResolved = maybeResolveAttribute(ua, resolvedList);
                             // An item in aggregations can reference to groupings explicitly, if groupings are not resolved yet and
@@ -607,7 +607,7 @@ private Aggregate resolveAggregate(Aggregate aggregate, List<Attribute> children
                             return ne;
                         });
                     }
-                    newAggregates.add(agg);
+                    newAggregates.add(maybeResolvedAgg);
                 }
 
                 // TODO: remove this when Stats interface is removed