* @description Returns the specified value if non-null, otherwise an empty array.
 * @param {Object} input - The object to investigate
 * @returns Object - The specified value if non-null, otherwise an empty array
 * @example {{ readField('jvm', 'files') | nullToEmpty }}
 */
function nullToEmpty(input) {
    let output;
    if (input) {
        output = input;
    } else {
        output = [];
    }

 * @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)) {

 * @param {String} objectName - The name of the particular object to find
 * @param {String} fieldName - The name of the field for the group to return
 * @returns String - The specified value
 * @example {{ files | byPlatform | categorize(branch.diff.files_metadata) | readField('jvm', 'name') }}
 */

function readField(objects, objectName, fieldName) {
    let group = Object.values(objects).find(s => s.name === objectName);

        /(?!\\)\?/g,
        () => '[^/]'
    ],

    // leading slash
    [

        // > A leading slash matches the beginning of the pathname.
        // > For example, "/*.c" matches "cat-file.c" but not "mozilla-sha1/sha1.c".
        // A leading slash matches the beginning of the pathname
        /^\//,
        () => '^'
    ],

 * @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");
const ignore = require('./ignore/index.js');

 * @param {string} Input - The GitHub username to check.
 * @returns {boolean} Returns true if the user is specified in any of the lists of Gradle BT team members above, otherwise false.
 * @example {{ pr.author | isEnabledUser }}
 */
function isEnabledUser(username) {

 * @returns {[Object]} Returns a list of objects for each platform containing info about the changes to files in that platform
 * @example {{ owners | categorize(branch.diff.files_metadata) }}
 */

function categorize(fileOwners, fileMetadatas) {
    const result = new Map();
    [...fileOwners.keys()].forEach(platform => {
        result.set(platform, {

 * @param {[FileMetadata]} fileMetadatas - gitStream's list of metadata about file changes in the PR including path
 * @returns {[Object]} Returns list of computed summary statistic objects for each platform in the input groupedFiles
 * @example {{ fileOwners | categorize(branch.diff.files_metadata) | changeStatistics(branch.diff.files_metadata) }}
 */
function computeStatistics(groupedFiles, fileMetadatas) {
    let totalAdditions = 0;
    let totalDeletions = 0

 * @param {Map} pr - The gitStream PR instance to check (includes metadata related to the pull request).
 * @returns {boolean} Returns true if the outlined conditions are met, otherwise false.
 * @example {{ 'platform_labels' | isEnabledAutomation(pr) }}
 */
function isEnabledAutomation(automationName, pr) {
    let result;
    const automationActivations = enabled.get(automationName) || [];

 *
 * @param {[Object]} statistics - list of summary data objects from computeStatistics
 * @param {String} title - description of how data is grouped
 * @returns {String} Returns the formatted HTMl table string.
 * @example {{ owners | categorize(branch.diff.files_metadata) | computeStatistics(branch.diff.files_metadata) | summaryTable('Platform') }}
 */
function summaryTable(statistics, title) {