Assertion '!throws' failed in iotjs_jhelper_call_ok

[renatahodovan]

IoT.js version:

Checked revision: dbd52a7
Build command: tools/build.py --buildtype=debug

OS:

Ubuntu 17.10

Test case:

process.on('exit', function() {});       
setTimeout(function() { Array.prototype.slice += 'B' }, 500);       

Backtrace:

iotjs/src/iotjs_binding.c:330: Assertion '!throws' failed.

[Backtrace]:

(gdb) bt
#0  iotjs_jhelper_call_ok (jfunc=2155, jthis=72, jargs=0x555555841020 <jargs_empty>) at iotjs/src/iotjs_binding.c:330
#1  0x0000555555571d05 in iotjs_process_next_tick () at iotjs/src/iotjs_binding_helper.c:89
#2  0x0000555555571e11 in iotjs_make_callback_with_result (jfunction=15859, jthis=14835, jargs=0x555555841020 <jargs_empty>)
    at iotjs/src/iotjs_binding_helper.c:125
#3  0x0000555555571dac in iotjs_make_callback (jfunction=15859, jthis=14835, jargs=0x555555841020 <jargs_empty>)
    at iotjs/src/iotjs_binding_helper.c:108
#4  0x0000555555581b1c in iotjs_timerwrap_on_timeout (timerwrap=0x555555883790)
    at iotjs/src/modules/iotjs_module_timer.c:92
#5  0x0000555555581796 in TimeoutHandler (handle=0x5555558837e0) at iotjs/src/modules/iotjs_module_timer.c:59
#6  0x00005555555fc78e in uv__run_timers (loop=0x555555841640 <default_loop_struct>)
    at iotjs/deps/libtuv/src/unix/timer.c:203
#7  0x00005555555f22f3 in uv_run (loop=0x555555841640 <default_loop_struct>, mode=UV_RUN_ONCE)
    at iotjs/deps/libtuv/src/unix/core.c:318
#8  0x000055555556f57b in iotjs_start (env=0x555555841440 <current_env>) at iotjs/src/iotjs.c:147
#9  0x000055555556f8f5 in iotjs_entry (argc=2, argv=0x7fffffffdec8) at iotjs/src/iotjs.c:218
#10 0x000055555556f0da in main (argc=2, argv=0x7fffffffdec8) at iotjs/iotjs_linux.c:19

^{Found by Fuzzinator with grammarinator}

[glistening]

I wonder why Array.prototype.slice += 'B' throws error.
iotjs throws TypeError for assigning non-function to function while others (jerry, node, jsc, etc.) don't.

$ cat t.js
Array.prototype.slice = null

$ iotjs t.js 
uncaughtException: TypeError: Expected a function.
$ jerry t.js  // no error
$ node t.js // no error

It is another bug that we must resolve before fixing the originally intended type of bug.

[DanielBallaSZTE]

@glistening I think it is the normal behaviour since:
Array.prototype.slice is set to null, that doesn't throw an error.
Evaluating Array.prototype.slice equals null.
However, in iotjs.js:95 there's a var callbacks = nextTickQueue.slice(0); which as slice expects a function.
I've checked in v8, and it has the same behaviour with the below code:

Array.prototype.slice = null;
var a = [3, 4, 5, 6];
a.slice(0);
TypeError: a.slice is not a function

[DanielBallaSZTE]

The issue is resolved, and can be closed.