string-utils.ts

export const firstLetter = (str: string): string => str[0];
export const toUppercase = (str: string): string => str.toUpperCase();
export const toLowercase = (str: string): string => str.toLowerCase();
export const trim = (str: string) => str.trim();

// https://stackoverflow.com/a/5717133/11351782
export function isValidUrl(str: string): boolean {
    const pattern = new RegExp('^(https?:\\/\\/)?'+ // protocol
            '((([a-z\\d]([a-z\\d-]*[a-z\\d])*)\\.)+[a-z]{2,}|'+ // domain name
            '((\\d{1,3}\\.){3}\\d{1,3}))'+ // OR ip (v4) address
            '(\\:\\d+)?(\\/[-a-z\\d%_.~+]*)*'+ // port and path
            '(\\?[;&a-z\\d%_.~+=-]*)?'+ // query string
            '(\\#[-a-z\\d_]*)?$','i'); // fragment locator

    return pattern.test(str);
}

export const capitalize = (str: string): string => str[0].toUpperCase() + str.slice(1, str.length).toLowerCase()


export const abbreviateUrl = (urlStr: string): string => {
    try {
        const {protocol, hostname, port, pathname, searchParams} = new URL(urlStr);

        if (urlStr.length > 40) {
            const portStr = port ? `:${port}` : '';
            const lastPartOfPath = last(pathname.split('/'));
            const searchParamsStr = searchParams.toString().length > 0 ? `?${searchParams.toString()}` : '';

            return `${protocol}//${hostname}${portStr}/.../${lastPartOfPath}${searchParamsStr}`;
        } else {
            return urlStr;
        }
    } catch (e) {
        return urlStr;
    }
}