}{
	{0xd800, 0xdc00, 0x10000},
	{0xd800, 0xdc01, 0x10001},
	{0xd808, 0xdf45, 0x12345},
	{0xdbff, 0xdfff, 0x10ffff},
	{0xd800, 'a', 0xfffd}, // illegal, replacement rune substituted
}

func TestDecodeRune(t *testing.T) {
	for i, tt := range decodeRuneTests {
		got := DecodeRune(tt.r1, tt.r2)
		if got != tt.want {
			t.Errorf("%d: DecodeRune(%q, %q) = %v; want %v", i, tt.r1, tt.r2, got, tt.want)
		}
	}
}