当一个函数从另一个函数调用时，如何正确检查？

function add(a, b) {
    if (typeof a !== 'number' || typeof b !== 'number') {
        throw new Error('Both arguments must be numbers');
    }
    return a + b;
}

function divide(a, b) {
    if (b === 0) {
        throw new Error('Cannot divide by zero');
    }
    return a / b;
}

async function fetchData(url) {
    try {
        const response = await fetch(url);
        if (!response.ok) {
            throw new Error('Network response was not ok');
        }
        const data = await response.json();
        return data;
    } catch (error) {
        console.error('Fetch error:', error);
    }
}