require-valid-default-prop.md

pageClass	sidebarDepth	title	description	since
rule-details	0	vue/require-valid-default-prop	enforce props default values to be valid	v3.13.0

vue/require-valid-default-prop

enforce props default values to be valid

• ⚙️ This rule is included in all of "plugin:vue/vue3-essential", *.configs["flat/essential"], "plugin:vue/essential", *.configs["flat/vue2-essential"], "plugin:vue/vue3-strongly-recommended", *.configs["flat/strongly-recommended"], "plugin:vue/strongly-recommended", *.configs["flat/vue2-strongly-recommended"], "plugin:vue/vue3-recommended", *.configs["flat/recommended"], "plugin:vue/recommended" and *.configs["flat/vue2-recommended"].

📖 Rule Details

This rule checks whether the default value of each prop is valid for the given type. It should report an error when default value for type Array or Object is not returned using function.

<script>
export default {
  props: {
    /* ✓ GOOD */
    // basic type check (`null` means accept any type)
    propA: Number,
    // multiple possible types
    propB: [String, Number],
    // a number with default value
    propD: {
      type: Number,
      default: 100
    },
    // object/array defaults should be returned from a factory function
    propE: {
      type: Object,
      default() {
        return { message: 'hello' }
      }
    },
    propF: {
      type: Array,
      default() {
        return []
      }
    },
    /* ✗ BAD */
    propA: {
      type: String,
      default: {}
    },
    propB: {
      type: String,
      default: []
    },
    propC: {
      type: Object,
      default: []
    },
    propD: {
      type: Array,
      default: []
    },
    propE: {
      type: Object,
      default: { message: 'hello' }
    }
  }
}
</script>

🔧 Options

Nothing.

📚 Further Reading

• Guide - Prop Validation

🚀 Version

This rule was introduced in eslint-plugin-vue v3.13.0

🔍 Implementation

• Rule source
• Test source