“承诺”仅指类型，但在此处用作值

Question

Error: [js] 'Promise' only refers to a type, but is being used as a value here.

I have set "checkJS": true and "jsx": "react" in jsconfig.json. This is not for ts.

async function readAsArrayBuffer(blob) {
return new Promise((resolve, reject) => {
         let reader = new FileReader();
         // @ts-ignore
        reader.addEventListener('load', e => resolve((e.target).result));
         // @ts-ignore
        reader.addEventListener('error', e => reject((e.target).error));
        reader.readAsArrayBuffer(blob);
    });
}

Script ofcourse working good.

How do I fix this unnecessary error?

Answer 1

I expect you need to target es6 or use a polyfill. I don't use VisualStudio but it looks like the following addition to your config might enable es6:

{
    "compilerOptions": { "target": "ES6" },
    //....
}