In committed code, prop definitions should always be as detailed as possible, specifying at least type(s).

Detailed prop definitions have two advantages:

• They document the API of the component, so that it's easy to see how the component is meant to be used.

• In development, Vue will warn you if a component is ever provided incorrectly formatted props, helping you catch potential sources of error.

Bad Practice

<script>

Vue.component('bar', {
  props: ['foo']
})

Vue.component('baz', {
  props: {
    foo: {},
  }
})
</script>

Recommended

<script>
Vue.component('foo', {
  props: {
    // Without options, just type reference
    foo: String,
    // With options with type field
    bar: {
      type: String,
      required: true,
    },
    // With options without type field but with validator field
    baz: {
      required: true,
      validator: function (value) {
        return (
          value === null ||
          Array.isArray(value) && value.length > 0
        )
      }
    }
  }
})
</script>