jsvGetArrayLength return 1

Hi,
I would like to help Espruino enable to do more things, so I try to add other functions to it.
But when I coding, jsvGetArrayLength return 1 all the time.
Could anyone teach me for this, thanks.

Here is the test code(added in the "jswrap_crypto.c"):

JsVar *jswrap_crypto_test(JsVar* arr){
  printf("%d",jsvIsArray(arr)?1:0);
  //1

  printf("%d",jsvGetLength(arr));
  //1

  printf("%d",jsvGetArrayLength(arr));
  //1

  printf("%d",jsvGetChildren(arr));
  //1

  return NULL;
}

/*JSON{
  "type" : "staticmethod",
  "class" : "crypto",
  "name" : "test",
  "generate" : "jswrap_crypto_test",
  "params" : [
    ["arr","JsVarArray","An array"]
  ],
  "return" : ["JsVar","A string"]
}
  this is a test function
 */

And also copied from "jsvArrayJoin", and the while will run once.

JsVar *jswrap_crypto_test(JsVar* arr){
  JsVar *str = jsvNewFromEmptyString();
  if (!str) return 0; // out of memory

  JsvIterator it;
  jsvIteratorNew(&it, arr, JSIF_EVERY_ARRAY_ELEMENT);
  JsvStringIterator itdst;
  jsvStringIteratorNew(&itdst, str, 0);

  while (!jspIsInterrupted() && jsvIteratorHasElement(&it)) {
    JsVar *key = jsvIteratorGetKey(&it);
    if (jsvIsInt(key)) {
      // add the value
      //JsVar *value = jsvIteratorGetValue(&it);
      //if (value && !jsvIsNull(value)) {
        //JsVar *valueStr = jsvAsString(value);
        //if (valueStr) { // could be out of memory
          //jsvStringIteratorAppendString(&itdst, valueStr, 0, JSVAPPENDSTRINGVAR_MAXLENGTH);
          //jsvUnLock(valueStr);
        //}
      //}
      //jsvUnLock(value);
      printf("h\n");
    }
    jsvUnLock(key);
    jsvIteratorNext(&it);
  }
  jsvIteratorFree(&it);
  jsvStringIteratorFree(&itdst);
  return str;
}

/*JSON{
  "type" : "staticmethod",
  "class" : "crypto",
  "name" : "test",
  "generate" : "jswrap_crypto_test",
  "params" : [
    ["arr","JsVarArray","An array"]
  ],
  "return" : ["JsVar","A string"]
}
  this is a test function
 */

After make, directly run on the Ubuntu 18.04, the test code is:

require("crypto").test(new Array(1,2,3));

Or

require("crypto").test([1,2,3]);