Errors in TypeScript vs. Try/Catch-CodePudding

How should I use Try/Catch in TypeScript? I don't want it to check for any errors in a given block because I already check for them (the error is expected and the state is controlled by the catch).

I have the code wrapped in Try/Catch (just example):

try {
    let data = localStorage.getItem('something');
    // Err. TS2345; I know, that's why you're in the try block
    data = JSON.parse(data);
    // Err. TS2531; I know, that's why you're in the try block
    data.exp = new Date(data.exp * 1000);
    return data;
} catch {
    return null;
}

TypeScript refuses to compile it. Is there any way I can tell TypeScript that I know about the error and I'm okay with it? I don't want to use //@ts-ignore on every line (assuming I can have a longer code) and I don't want to turn off strict mode. Is there any better solution?

CodePudding user response：

TypeScript's purpose is to help you with coding errors caused by type issues. It's giving you TS2345 because you're passing string | null into JSON.parse (which expects just string), and it's giving you TS2531 and TS2339 because your code is using data as though it won't be null (but it may well be) and as though it has an exp property (which as far as TypeScript knows, it doesn't).

If you want to disable type checking for data, use the any type:

try {
    let data: any = localStorage.getItem('something');
//          ^^^^^−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− here
    data = JSON.parse(data);
    data.exp = new Date(data.exp * 1000);
    return data;
} catch {
    return null;
}

From the linked documentation:

any

TypeScript also has a special type, any, that you can use whenever you don’t want a particular value to cause typechecking errors.