How do I get the javascript error trace?

[sleungcy]

Hi,

I am trying to debug this issue Object has no memeber 'assign'

How can I get the stacktrace when there is an error in the javascript?
I am using e.stack, but it's giving me an undefined value.

JS code:
result.error = "Render Error: " + e + "\n\t\tStackTrace: " + e.stack + "."

outcome:
Render Error: TypeError: Object has no member 'assign'
StackTrace: undefined.

[dop251]

Currently the only way to get the stack trace is by converting the returned error into *goja.Exception and calling its String() method, e.g.:

func TestStacktrace(t *testing.T) {
	const SCRIPT = `
	function f() {
		throw new Error("Test");
	}

	f();
	`

	vm := New()
	_, err := vm.RunString(SCRIPT)
	if ex, ok := err.(*Exception); ok {
		t.Log(ex.String())
	}
}

This will print

Error: Test
			at f (<eval>:3:9(4))
			at <eval>:6:3(7)

Error.stack property is not part of any specification, however it seems to be present in all major implementations, so I may add it in the future.

As for Object.assign, see #24

[sleungcy]

Thanks, I got the problem fixed.