Strange behavior in raw embed versus running JS directly

interop
reasonreact
#1

I have two different results from running the following code, one is in JS and another the same code embedded using raw embed.

    let arrayMove : (array(int), int, int) => array(int) = [%raw
      (arr, previousIndex, newIndex) => 
      "{
        const array = arr.slice(0);
        if (newIndex >= array.length) {
          let k = newIndex - array.length;
          while (k-- + 1) {
            array.push(undefined);
          }
        }
        array.splice(newIndex, 0, array.splice(previousIndex, 1)[0]);
        return array;
      }"
    ];

If I run the JS snippet in the console, I get the correct output,

> arrayMove([1, 2, 3, 4], 0, 3)
[2, 3, 4, 1]

Now in Reason though I get a different output.

arrayMove([|1, 2, 3, 4|], 0, 3)

that gives me [| 1, 2, 3, 4 |].

What’s the reason behind this strange behavior? Initially I thought it had to do with immutability but array in Reason is mutable and it maps straightforwardly to JavaScript arrays.

#2

That’s strange, I’ve pasted your code into the playground and it works fine:

Are you doing any postprocessing on your JS output?