merge-headers/dist/index.js

Easily merge HTTP headers

function isObject(value) {
    return value !== null && typeof value === 'object';
}
function merge(...sources) {
    const result = {};
    for (const source of sources) {
        if (!isObject(source)) {
            throw new TypeError('All arguments must be of type object');
        }
        const headers = new Headers(source);
        for (const [key, value] of headers.entries()) {
            if ((value === undefined || value === 'undefined')) {
                delete result[key];
            }
            else {
                result[key] = value;
            }
        }
    }
    return new Headers(result);
}
module.exports = merge;