[Vuejs]-Rendering component on runtime after Http request in VueJS

There is no need to have currentTabComponent computed method.

You can just make your HTTP call and update currentTab when it is done.

Something like this:

mounted() {
  fetch('someHttpUrl')
  .then(response => response.json())
  .then(data => {
    this.currentTab = 'Comp1'
  });
  .catch(err => {
    this.currentTab = 'Comp2'
   })
}

I also removed the method named check as it seemed redundant.