[JS backend] Interaction between if-expressions and addr leads to undefined

[dawkot]

Example

var
  x = @["test"]
  y = if true: x.addr else: x.addr

{.emit: "console.log(`y`)".}

Current Output

undefined

$ nim -v
Nim Compiler Version 1.6.2

[hamidb80]

I don't understand what to expect exactly.

[dawkot]

Pointers seem to be supported on JS, if that's what you're asking.

[bung87]

you can't simply pass ptr seq[string] into js function, but here's another problem , even echo repr y doesn't work, it prints ref 101 --> @[]

[dawkot]

From what I recall if you remove the if expression and simply leave y = x.addr, it did print something other than undefined (I guess the implementation detail of how ptr is handled in JS backend).

I think the issue with repr y you mentioned is a side effect of y being undefined, like my output suggested. So there is something wrong going on with the assignment itself.