* @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 = [];
    }
    console.log("nullToEmpty: " + output);
    return output;
}

}

function codeownersMapping(data) {
    return data
        .toString()
        .split('\n')
        .filter(x => x && !x.startsWith('#'))
        .map(x => x.split("#")[0])
        .map(x => {
            const line = x.trim();
            const [path, ...owners] = line.split(/\s+/);
            return {path, owners};
        });
}

function resolveCodeowners(mapping, file) {

 * @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)) {
            result.set(platform, []);
        }