javascript - 未处理的 promise 拒绝 TypeError

Question

我正在使用 async/await 查询数据库并获取结果，但我不知道为什么浏览器控制台会出现此错误:

Unhandled promise rejection TypeError: "games is undefined"

我有两个函数，异步的 getData 和调用 getGames:

getGames(){
    let query = HOMELF1_NEXT_GAMES;
    var data = {
        "query": query,
        "variables": null
    }
    fetch(URL_FEB_API, {
        method: "POST",
        headers: {
            "Accept"        :   "application/json",
            "content-type"  :   "application/json"
        },
        body: JSON.stringify(data)
    })
    .then(response => {
        return response.json()
    })
    .then(data => {
        console.log("End query");
        return data;
    })
    .catch(err => {
        console.log("Error: " + err)
    })
}

async getData(){
    console.log("Before getGames");
    let games = await this.getGames();
    console.log("After getGames");
    console.log("games: " + games.length)
}

componentDidMount(){
    this.getData();
};

在浏览器控制台中我得到了这个结果:

为什么不在这里工作 async/await？我做错了什么？

Answer 1

你刚刚忘记了return

getGames(){
    let query = HOMELF1_NEXT_GAMES;
    var data = {
        "query": query,
        "variables": null
    }
     \/ here
    return fetch(URL_FEB_API, {
        method: "POST",
        headers: {
            "Accept"        :   "application/json",
            "content-type"  :   "application/json"
        },
        body: JSON.stringify(data)
    })
    .then(response => {
        return response.json()
    })
    .then(data => {
        console.log("End query");
        return data;
    })
    .catch(err => {
        console.log("Error: " + err)
    })
}

async getData(){
    console.log("Before getGames");
    let games = await this.getGames();
    console.log("After getGames");
    console.log("games: " + games.length)
}

componentDidMount(){
    this.getData();
};