1 files changed, 130 insertions, 0 deletions
diff --git a/src/zvalidation.js b/src/zvalidation.js
new file mode 100644
index 0000000..e8618e9
--- /dev/null
+++ b/src/zvalidation.js
@@ -0,0 +1,130 @@
+"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;
+    },
+};