Easy way to calculate all commits count from one user

get_all_commits_count_from_user.js

const base_url = 'https://api.github.com';

function httpGet(theUrl, return_headers) {
    var xmlHttp = new XMLHttpRequest();
    xmlHttp.open("GET", theUrl, false); // false for synchronous request
    xmlHttp.send(null);
    if (return_headers) {
        return xmlHttp
    }
    return xmlHttp.responseText;
}

function get_all_commits_count(owner, repo, sha) {
    let first_commit = get_first_commit(owner, repo);
    let compare_url = base_url + '/repos/' + owner + '/' + repo + '/compare/' + first_commit + '...' + sha;
    let commit_req = httpGet(compare_url);
    let commit_count = JSON.parse(commit_req)['total_commits'] + 1;
    return commit_count
}

function get_first_commit(owner, repo) {
    let url = base_url + '/repos/' + owner + '/' + repo + '/commits';
    let req = httpGet(url, true);
    let first_commit_hash = '';
    if (req.getResponseHeader('Link')) {
        let page_url = req.getResponseHeader('Link').split(',')[1].split(';')[0].split('<')[1].split('>')[0];
        let req_last_commit = httpGet(page_url);
        let first_commit = JSON.parse(req_last_commit);
        first_commit_hash = first_commit[first_commit.length - 1]['sha']
    } else {
        let first_commit = JSON.parse(req.responseText);
        first_commit_hash = first_commit[first_commit.length - 1]['sha'];
    }
    return first_commit_hash;
}

function get_all_commits_count_from_all_repos(owner) {

    let url = base_url + '/users/' + owner + '/repos';
    let repos = httpGet(url);
    let count = 0;

    if(isInvalidJsonString(repos)){
        return 0;
    }

    repos = JSON.parse(repos);
    for (let repo of repos) {
        count = count + get_all_commits_count(owner, repo.name, repo.default_branch);
    }

    return count;
}

function isInvalidJsonString(tester) {
    if (/^\s*$|undefined/.test(tester) || !(/number|object|array|string|boolean/.test(typeof tester))) {
        return true;
    }
    return false;
}

get_all_commits_count_from_all_repos('medeirosinacio');

ref: https://gist.github.com/yershalom/a7c08f9441d1aadb13777bce4c7cdc3b