From 773d661b684777610961ea0cb628804c69bb947d Mon Sep 17 00:00:00 2001
From: Yuce Tekol <yucetekol@gmail.com>
Date: Mon, 21 Jan 2019 18:02:51 +0300
Subject: [PATCH] GroupBy legacy Rows

---
 executor.go      | 13 ++++++++++---
 executor_test.go | 14 ++++++++++++++
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/executor.go b/executor.go
index f390f41af..fdc19b7a7 100644
--- a/executor.go
+++ b/executor.go
@@ -1090,7 +1090,8 @@ func (e *executor) executeGroupByShard(ctx context.Context, index string, c *pql
 
 func (e *executor) executeRows(ctx context.Context, index string, c *pql.Call, shards []uint64, opt *execOptions) (RowIDs, error) {
 	// Fetch field name from argument.
-	// Check "field" first for backwards compatibility
+	// Check "field" first for backwards compatibility.
+	// TODO: remove at Pilosa 2.0
 	var fieldName string
 	var ok bool
 	if fieldName, ok = c.Args["field"].(string); ok {
@@ -2763,10 +2764,16 @@ func newGroupByIterator(rowIDs []RowIDs, children []*pql.Call, filter *Row, inde
 		fields: make([]FieldRow, len(children)),
 	}
 
+	var fieldName string
+	var ok bool
 	ignorePrev := false
 	for i, call := range children {
-		fieldName, ok := call.Args["_field"].(string)
-		if !ok {
+		// Check "field" first for backwards compatibility.
+		// TODO: remove at Pilosa 2.0
+		if fieldName, ok = call.Args["field"].(string); ok {
+			call.Args["_field"] = fieldName
+		}
+		if fieldName, ok = call.Args["_field"].(string); !ok {
 			return nil, errors.Errorf("%s call must have field with valid (string) field name. Got %v of type %[2]T", call.Name, call.Args["_field"])
 		}
 		if holder.Field(index, fieldName) == nil {
diff --git a/executor_test.go b/executor_test.go
index 4c2bbedd7..110717971 100644
--- a/executor_test.go
+++ b/executor_test.go
@@ -3300,6 +3300,20 @@ func TestExecutor_Execute_GroupBy(t *testing.T) {
 			}
 		})
 
+		// backwards compatibility
+		// TODO: remove at Pilosa 2.0
+		t.Run("BasicLegacy", func(t *testing.T) {
+			expected := []pilosa.GroupCount{
+				{Group: []pilosa.FieldRow{{Field: "general", RowID: 10}, {Field: "sub", RowID: 100}}, Count: 3},
+				{Group: []pilosa.FieldRow{{Field: "general", RowID: 10}, {Field: "sub", RowID: 110}}, Count: 1},
+				{Group: []pilosa.FieldRow{{Field: "general", RowID: 11}, {Field: "sub", RowID: 110}}, Count: 1},
+				{Group: []pilosa.FieldRow{{Field: "general", RowID: 12}, {Field: "sub", RowID: 110}}, Count: 1},
+			}
+
+			results := c.Query(t, "i", `GroupBy(Rows(field=general), Rows(sub))`).Results[0].([]pilosa.GroupCount)
+			test.CheckGroupBy(t, expected, results)
+		})
+
 		t.Run("Basic", func(t *testing.T) {
 			expected := []pilosa.GroupCount{
 				{Group: []pilosa.FieldRow{{Field: "general", RowID: 10}, {Field: "sub", RowID: 100}}, Count: 3},