SERVER-67780 Incorrect $group rewrite for timeseries collection when the accumulator uses meta field

1 files changed, 43 insertions, 0 deletions

diff --git a/jstests/core/timeseries/timeseries_groupby_reorder.js b/jstests/core/timeseries/timeseries_groupby_reorder.js
new file mode 100644
index 00000000000..29d07f8b4fa
--- /dev/null
+++ b/jstests/core/timeseries/timeseries_groupby_reorder.js
@@ -0,0 +1,43 @@
+/**
+ * Test the behavior of $group on time-series collections.
+ *
+ * @tags: [
+ *   directly_against_shardsvrs_incompatible,
+ *   does_not_support_stepdowns,
+ *   does_not_support_transactions,
+ *   requires_fcv_61,
+ * ]
+ */
+(function() {
+"use strict";
+
+load("jstests/libs/fixture_helpers.js");
+load("jstests/core/timeseries/libs/timeseries.js");
+
+const coll = db.timeseries_groupby_reorder;
+coll.drop();
+
+assert.commandWorked(
+    db.createCollection(coll.getName(), {timeseries: {metaField: "meta", timeField: "t"}}));
+
+const t = new Date();
+assert.commandWorked(coll.insert({_id: 0, t: t, b: 1, c: 1}));
+assert.commandWorked(coll.insert({_id: 0, t: t, b: 2, c: 2}));
+assert.commandWorked(coll.insert({_id: 0, t: t, b: 3, c: 3}));
+
+// Test reordering the groupby and internal unpack buckets.
+if (!isMongos(db)) {
+    const res = coll.explain("queryPlanner").aggregate([
+        {$group: {_id: '$meta', accmin: {$min: '$b'}, accmax: {$max: '$c'}}}
+    ]);
+
+    assert.docEq(res.stages[1], {
+        "$group":
+            {_id: "$meta", accmin: {"$min": "$control.min.b"}, accmax: {"$max": "$control.max.c"}}
+    });
+}
+
+const res = coll.aggregate([{$group: {_id: '$meta', accmin: {$min: '$b'}, accmax: {$max: '$c'}}}])
+                .toArray();
+assert.docEq(res, [{"_id": null, "accmin": 1, "accmax": 3}]);
+})();