JS.VUE.PREFER.PROP.TYPE.BOOLEAN.FIRST

Prefer property type boolean first

Some problems reported by this rule are manually fixable by editor suggestions (https://eslint.org/docs/developer-guide/working-with-rules#providing-suggestions).

Rule Details

When declaring types of a property in component, we can use array style to accept multiple types.

When using components in template, we can use shorthand-style property if its value is true.

However, if a property allows Boolean or String and we use it with shorthand form in somewhere else, different types order can introduce different behaviors: If Boolean comes first, it will be true; if String comes first, it will be "" (empty string).

See this demo (https://sfc.vuejs.org/#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).

{'vue/prefer-prop-type-boolean-first': ['error']}

Copy

<script>
export default {
  props: {
    // GOOD
    a: Boolean,
    b: String,
    c: [Boolean, String],
    d: {
      type: [Boolean, String]
    },

    // BAD
    e: [String, Boolean],
    f: {
      type: [String, Boolean]
    }
  }
}
</script>