Define emits with TypeScript

Use the type-based declaration syntax instead of runtime declaration. This provides better type safety and IDE support for emitted events. The type-based syntax allows TypeScript to infer correct types for the emit function and validate event payloads at compile time.

Type-based syntax: const emit = defineEmits<{ eventName: [payload: Type] }>() Runtime syntax: const emit = defineEmits(['eventName']) (avoid in TypeScript)

Rule for AI agents

- ALWAYS use type-based syntax for defineEmits in TypeScript instead of runtime array syntax

Eslint rule

• https://eslint.vuejs.org/rules/define-emits-declaration.html (not in presets, requires config)

Source

• https://vuejs.org/api/sfc-script-setup.html#type-only-props-emit-declarations