Vue Guideline: Emits — Define emits with defineEmits. Description: Type-safe event emissions. Do: defineEmits with types. Don't: Emit without definition. Good Example: defineEmits<{ change: [id: number] }>(). Bad Example: emit('change', id) without define. Severity: Medium. Docs: https://vuejs.org/guide/typescript/composition-api.html#typing-component-emits.