package repo

import "testing"

func TestPreviewTruncatesOnUTF8Boundary(t *testing.T) {
	// 「巡」是 3 字节；在 max=4 处切会切进第 2 个字符中间
	s := "巡检报告"
	got := preview(s, 4)
	if got != "巡..." {
		t.Fatalf("按 UTF-8 边界截断失败：%q", got)
	}
	for i, r := range got {
		if r == 0xFFFD {
			t.Fatalf("位置 %d 出现替换符，说明切在了字符中间", i)
		}
	}
}

func TestPreviewKeepsShortBodyIntact(t *testing.T) {
	if got := preview("短正文", 240); got != "短正文" {
		t.Fatalf("未超长却被改动：%q", got)
	}
}