Nuxt.js + TypescriptでVuex内をタイプセーフにする - Qiitatype State = { hoge: string; fuga: number; }; type ChangeHogePayload = { value: string }; type ChangeFugaPayload = { value: number }; export const state: () => State = (): State => ({ hoge: '', fuga: 0, }); type Mutations = { changeHoge: (state: State, payload: ChangeHogePayload) => void, changeFuga: (state: State, payload: ChangeFugaPayload) => void, incrementFuga: (state: State) => void, }; expo
TypeScript 2.8 の Conditional Types について - Qiita
