deltas.Group(GroupName("^[^:]*"))

ledger/deltas_test.go

@@ -3,6 +3,32 @@ package ledger
 import "testing"
 
 func TestDeltas(t *testing.T) {
+	t.Run("Groups", func(t *testing.T) {
+		deltas := Deltas{
+			{Name: "a1"},
+			{Name: "b1"},
+			{Name: "b2"},
+			{Name: "b3"},
+		}
+
+		deltas = deltas.Group(GroupName("^."))
+		if len(deltas) != 4 {
+			t.Error(len(deltas))
+		}
+		if deltas[0].Name != "a" {
+			t.Error(deltas[0].Name)
+		}
+		if deltas[1].Name != "b" {
+			t.Error(deltas[1].Name)
+		}
+		if deltas[2].Name != "b" {
+			t.Error(deltas[2].Name)
+		}
+		if deltas[3].Name != "b" {
+			t.Error(deltas[3].Name)
+		}
+	})
+
 	t.Run("balances", func(t *testing.T) {
 		deltas := Deltas{
 			{Name: "a", Value: 0},