package billingsync

import (
	"testing"
	"time"
)

// TestBillingYesterdayAt 验证 UTC 服务器按中国业务时区计算昨日。 // Logan.Li
func TestBillingYesterdayAt(t *testing.T) {
	now := time.Date(2026, 7, 28, 21, 30, 0, 0, time.UTC)
	if got := billingYesterdayAt(now); got != "2026-07-28" {
		t.Fatalf("昨日日期错误: got=%s want=2026-07-28", got)
	}
}