Bug updating global arrays

[Andrei]

@blechdom

It only fails after I have copied a current_array to the last_array. Almost always immediately after I have done so. It's as if, updating the current_array also updates last_array,

HI, indeed, this unwanted behavior will happen when you try to copy an array to another array using the assignment operator (or using the flow.set like you did). In JavaScript assigning current_array to last_array will make last_array to point to the same elements of current_array, i.e, changing current_array will affect last_array and vice_versa.

var current_array = flow.get("current_array");
flow.set("last_array", current_array);
msg.payload = "set last array to current array";
return msg;

Try to use this statement to copy current_array to last_array:

last_array = [...current_array];

Only then you save last_array to the flow context

flow.set("last_array", last_array);

edit:

Therefore this is how your last function will looks like:

var current_array = flow.get("current_array");
last_array = [...current_array];
flow.set("last_array", last_array);
msg.payload = "set last array to current array";
return msg;