metamask-extension/ui/app/components/ui/tooltip.js

const Component = require('react').Component
const h = require('react-hyperscript')
const inherits = require('util').inherits
const ReactTooltip = require('react-tooltip-component')

module.exports = Tooltip

inherits(Tooltip, Component)
function Tooltip () {
  Component.call(this)
}

Tooltip.prototype.render = function () {
  const props = this.props
  const { position, title, children } = props

  return h(ReactTooltip, {
    position: position || 'left',
    title,
    fixed: true,
  }, children)
}