Data Option breaking

    • BREAKING: component option declaration no longer accepts a plain JavaScript object and expects a function declaration.

    For example:

    In 3.x, the data option has been standardized to only accept a that returns an object.

    1.   import { createApp } from 'vue'
    3.   createApp({
    4.     data() {
    6.       }
    7.     }
    8.   }).mount('#app')
    9. </script>

    For users relying on the object declaration, we recommend:

    • Extracting the shared data into an external object and using it as a property in data