How to try-catch errors with typescript

JavaScript errors are of type any but if we want to read the error message we can use err instanceof Error

try {
//somthing
} catch (error) {
if (error instanceof Error) console.error(error.message);
}

We can handle errors with:

type
ErrorWithMessage = {
    message: string
}

function isErrorWithMessage(error: unknown): error

is
ErrorWithMessage
{
    return (
        typeof error === 'object' &&
        error !== null &&
        'message' in error &&
        typeof (error
    as
    Record < string, unknown >
).
    message === 'string'
)
}

function toErrorWithMessage(maybeError: unknown): ErrorWithMessage {
    if (isErrorWithMessage(maybeError)) return maybeError

    try {
        return new Error(JSON.stringify(maybeError))
    } catch {
        // fallback in case there's an error stringifying the maybeError
        // like with circular references for example.
        return new Error(String(maybeError))
    }
}

function getErrorMessage(error: unknown) {
    return toErrorWithMessage(error).message
}

---

References:

• https://kentcdodds.com/blog/get-a-catch-block-error-message-with-typescript