* @param {Object} pr - the gitStream's pr context variable
 * @param {string} token - access token with repo:read scope, used to read the CODEOWNERS file
 * @param {string} pathToCodeOwners - path from repo root to CODEOWNERS file
 * @returns {Map} - Map from owner name to list of files they own
 * @example {{ files | byCodeowner(pr, env.CODEOWNERS_TOKEN, '.github/CODEOWNERS') }}
 **/

const { Octokit } = require("@octokit/rest");

/**
 * @module byPlatform
 * @description Groups the PR's files by platform based on the file's path.
 * @param {string[]} files - the gitStream's files context variable
 * @returns {Map} - Map from platform to list of files in this PR in it
 * @example {{ owners | byPlatform }}
 */
function byPlatform(files) {
    const result = new Map();
    files.forEach(file => {
        const platform = getPlatform(file);
        if (!result.has(platform)) {