@masx200/zmodem.js/src/zvalidation.js

ZMODEM file transfers in JavaScript

"use strict";

var Zmodem = module.exports;

Object.assign(
    Zmodem,
    require("./zerror"),
);

const LOOKS_LIKE_ZMODEM_HEADER = /\*\x18[AC]|\*\*\x18B/;

function _validate_number(key, value) {
    if (value < 0) {
        throw new Zmodem.Error(
            "validation",
            "“" + key + "” (" + value + ") must be nonnegative.",
        );
    }

    if (value !== Math.floor(value)) {
        throw new Zmodem.Error(
            "validation",
            "“" + key + "” (" + value + ") must be an integer.",
        );
    }
}

/** Validation logic for zmodem.js
 *
 * @exports Validation
 */
Zmodem.Validation = {
    /**
     * Validates and normalizes a set of parameters for an offer to send.
     * NOTE: This returns “mtime” as epoch seconds, not a Date. This is
     * inconsistent with the get_details() method in Session, but it’s
     * more useful for sending over the wire.
     *
     * @param {FileDetails} params - The file details. Some fairly trivial
     * variances from the specification are allowed.
     *
     * @return {FileDetails} The parameters that should be sent. `mtime`
     * will be a Date rather than a number.
     */
    offer_parameters: function offer_parameters(params) {
        if (!params.name) {
            throw new Zmodem.Error("validation", "Need “name”!");
        }

        if (typeof params.name !== "string") {
            throw new Zmodem.Error(
                "validation",
                "“name” (" + params.name + ") must be a string!",
            );
        }

        //So that we can override values as is useful
        //without affecting the passed-in object.
        params = Object.assign({}, params);

        if (LOOKS_LIKE_ZMODEM_HEADER.test(params.name)) {
            console.warn(
                "The filename " + JSON.stringify(name) +
                    " contains characters that look like a ZMODEM header. This could corrupt the ZMODEM session; consider renaming it so that the filename doesn’t contain control characters.",
            );
        }

        if (params.serial !== null && params.serial !== undefined) {
            throw new Zmodem.Error("validation", "“serial” is meaningless.");
        }

        params.serial = null;

        ["size", "mode", "files_remaining", "bytes_remaining"].forEach(
            function (k) {
                var ok;
                switch (typeof params[k]) {
                    case "object":
                        ok = params[k] === null;
                        break;
                    case "undefined":
                        params[k] = null;
                        ok = true;
                        break;
                    case "number":
                        _validate_number(k, params[k]);

                        ok = true;
                        break;
                }

                if (!ok) {
                    throw new Zmodem.Error(
                        "validation",
                        "“" + k + "” (" + params[k] +
                            ") must be null, undefined, or a number.",
                    );
                }
            },
        );

        if (typeof params.mode === "number") {
            params.mode |= 0x8000;
        }

        if (params.files_remaining === 0) {
            throw new Zmodem.Error(
                "validation",
                "“files_remaining”, if given, must be positive.",
            );
        }

        var mtime_ok;
        switch (typeof params.mtime) {
            case "object":
                mtime_ok = true;

                if (params.mtime instanceof Date) {
                    var date_obj = params.mtime;
                    params.mtime = Math.floor(date_obj.getTime() / 1000);
                    if (params.mtime < 0) {
                        throw new Zmodem.Error(
                            "validation",
                            "“mtime” (" + date_obj +
                                ") must not be earlier than 1970.",
                        );
                    }
                } else if (params.mtime !== null) {
                    mtime_ok = false;
                }

                break;

            case "undefined":
                params.mtime = null;
                mtime_ok = true;
                break;
            case "number":
                _validate_number("mtime", params.mtime);
                mtime_ok = true;
                break;
        }

        if (!mtime_ok) {
            throw new Zmodem.Error(
                "validation",
                "“mtime” (" + params.mtime +
                    ") must be null, undefined, a Date, or a number.",
            );
        }

        return params;
    },
};