Cannot use tooltip's option placement with function ???

I use webpack 4 with two package: “popper.js”: “^1.14.3” “tooltip.js”: “^1.2.0”

I have config tooltip with option:

new Tooltip(document.getElementById('ttip'),{
  html: true,
  placement: 'left',
  title () {
    return this.dataset.ttipTitle
  }
})

It work fine. But i try change placement with function

new Tooltip(document.getElementById('ttip'),{
  html: true,
  placement () {
    return 'left'
  },
  title () {
    return this.dataset.ttipTitle
  }
})

It have error

Uncaught TypeError: placement.indexOf is not a function

I don’t know why. Please help me fix it !

Thank you !

[piglovesyou]

@FezVrasta So all the PlacementFunction in the source code are supposed to be deleted? I’ll take care of it.

[FezVrasta]

The documentation is wrong, I’m sorry. We need to update it.