[Node.js] Finds the pathname of the parent module's package descriptor file.

findParentPkgDesc.js

var fs = require('fs');
var path = require('path');

/**
 * Finds the pathname of the parent module's package descriptor file. If the
 * directory is undefined (the default case), then it is set to the directory
 * name of the parent module's filename. If no package.json file is found, then
 * the parent directories are recursively searched until the file is found or
 * the root directory is reached. Returns the pathname if found or null if not.
 */
function findParentPkgDesc(directory) {
    if (!directory) {
        directory = path.dirname(module.parent.filename);
    }
    var file = path.resolve(directory, 'package.json');
    if (fs.existsSync(file) && fs.statSync(file).isFile()) {
        return file;
    }
    var parent = path.resolve(directory, '..');
    if (parent === directory) {
        return null;
    }
    return findParentPkgDesc(parent);
}