javascript - ESlint 错误，类型 '() => Promise' 缺少类型 'Promise' 中的以下属性 : then, 捕获，[Symbol.toStringTag]，最后

Question

我遇到了一个错误，我只能通过添加 any 来修复它作为返回值。

export const dbConnections: any = {};

export const connectDb: Promise<void> = async () => {
    if (dbConnections.isConnected) {
        return;
    }

    try {
        const db = await mongoose.connect(config.get('mongoURI'), {
            useNewUrlParser: true,
            useUnifiedTopology: true,
            useFindAndModify: false,
            useCreateIndex: true,
        });

        dbConnections.isConnected = db.connections[0].readyState;
    } catch (err) {
        createError('Error caught connecting to db!', err);
    }
};

这会引发错误，

export const connectDb: Promise<void> = async () => {
                                        ^^^^^^^^^^^^^
Type '() => Promise<void>' is missing the following properties
  from type 'Promise<void>': then, catch, [Symbol.toStringTag], finally

如果我这样做 any而不是 Promise<void> ，然后错误消失，但这显然不是我试图解决这个问题的方式。如何解决此 lint 错误？

Answer 1

问题在于函数声明。您需要将返回类型指定为 Promise<void> .

export const connectDb = async (): Promise<void> => {
    if (dbConnections.isConnected) {
        return;
    }

    try {
        const db = await mongoose.connect(config.get('mongoURI'), {
            useNewUrlParser: true,
            useUnifiedTopology: true,
            useFindAndModify: false,
            useCreateIndex: true,
        });

        dbConnections.isConnected = db.connections[0].readyState;
    } catch (err) {
        createError('Error caught connecting to db!', err);
    }
};