fn test_unescape()

in src/tokenizer.rs [3505:3558]
50 lines of code
1 McCabe index (conditional complexity)

    fn test_unescape() {
        check_unescape(r"\b", Some("\u{0008}"));
        check_unescape(r"\f", Some("\u{000C}"));
        check_unescape(r"\t", Some("\t"));
        check_unescape(r"\r\n", Some("\r\n"));
        check_unescape(r"\/", Some("/"));
        check_unescape(r"/", Some("/"));
        check_unescape(r"\\", Some("\\"));

        // 16 and 32-bit hexadecimal Unicode character value
        check_unescape(r"\u0001", Some("\u{0001}"));
        check_unescape(r"\u4c91", Some("\u{4c91}"));
        check_unescape(r"\u4c916", Some("\u{4c91}6"));
        check_unescape(r"\u4c", None);
        check_unescape(r"\u0000", None);
        check_unescape(r"\U0010FFFF", Some("\u{10FFFF}"));
        check_unescape(r"\U00110000", None);
        check_unescape(r"\U00000000", None);
        check_unescape(r"\u", None);
        check_unescape(r"\U", None);
        check_unescape(r"\U1010FFFF", None);

        // hexadecimal byte value
        check_unescape(r"\x4B", Some("\u{004b}"));
        check_unescape(r"\x4", Some("\u{0004}"));
        check_unescape(r"\x4L", Some("\u{0004}L"));
        check_unescape(r"\x", Some("x"));
        check_unescape(r"\xP", Some("xP"));
        check_unescape(r"\x0", None);
        check_unescape(r"\xCAD", None);
        check_unescape(r"\xA9", None);

        // octal byte value
        check_unescape(r"\1", Some("\u{0001}"));
        check_unescape(r"\12", Some("\u{000a}"));
        check_unescape(r"\123", Some("\u{0053}"));
        check_unescape(r"\1232", Some("\u{0053}2"));
        check_unescape(r"\4", Some("\u{0004}"));
        check_unescape(r"\45", Some("\u{0025}"));
        check_unescape(r"\450", Some("\u{0028}"));
        check_unescape(r"\603", None);
        check_unescape(r"\0", None);
        check_unescape(r"\080", None);

        // others
        check_unescape(r"\9", Some("9"));
        check_unescape(r"''", Some("'"));
        check_unescape(
            r"Hello\r\nRust/\u4c91 SQL Parser\U0010ABCD\1232",
            Some("Hello\r\nRust/\u{4c91} SQL Parser\u{10abcd}\u{0053}2"),
        );
        check_unescape(r"Hello\0", None);
        check_unescape(r"Hello\xCADRust", None);
    }