Vue component type safety

When defining Vue components with TypeScript, use appropriate component definition patterns to ensure proper type inference and avoid breaking type changes.

For proper typing of component props:

1. Use the correct helper for your component definition needs. For example, DeclareComponent may be more appropriate than defineComponent when you need to expose prop types in a specific way.

2. When providing default values for function props, remember they’re handled differently than object/array defaults:

// Correct way to define function props with defaults
props: {
  handler: {
    type: Function,
    // Function props don't need to be wrapped in factory functions
    default() {
      return (value) => console.log(value)
    }
  },
  // While object defaults need factory functions
  objProp: {
    type: Object,
    default: () => ({ key: 'value' })
  }
}

1. Be cautious when modifying type definitions or signatures of public APIs, as these can introduce breaking changes for consumers. Maintain the expected type argument order for exported types like DefineComponent.

By following these practices, you’ll ensure your Vue components have proper TypeScript support while maintaining compatibility with Vue’s type system.