source: trip-planner-front/node_modules/enhanced-resolve/lib/DescriptionFileUtils.js

/*
        MIT License http://www.opensource.org/licenses/mit-license.php
        Author Tobias Koppers @sokra
*/

"use strict";

const forEachBail = require("./forEachBail");

/** @typedef {import("./Resolver")} Resolver */
/** @typedef {import("./Resolver").ResolveContext} ResolveContext */

/**
 * @typedef {Object} DescriptionFileInfo
 * @property {any=} content
 * @property {string} path
 * @property {string} directory
 */

/**
 * @callback ErrorFirstCallback
 * @param {Error|null=} error
 * @param {DescriptionFileInfo=} result
 */

/**
 * @param {Resolver} resolver resolver
 * @param {string} directory directory
 * @param {string[]} filenames filenames
 * @param {DescriptionFileInfo|undefined} oldInfo oldInfo
 * @param {ResolveContext} resolveContext resolveContext
 * @param {ErrorFirstCallback} callback callback
 */
function loadDescriptionFile(
        resolver,
        directory,
        filenames,
        oldInfo,
        resolveContext,
        callback
) {
        (function findDescriptionFile() {
                if (oldInfo && oldInfo.directory === directory) {
                        // We already have info for this directory and can reuse it
                        return callback(null, oldInfo);
                }
                forEachBail(
                        filenames,
                        (filename, callback) => {
                                const descriptionFilePath = resolver.join(directory, filename);
                                if (resolver.fileSystem.readJson) {
                                        resolver.fileSystem.readJson(descriptionFilePath, (err, content) => {
                                                if (err) {
                                                        if (typeof err.code !== "undefined") {
                                                                if (resolveContext.missingDependencies) {
                                                                        resolveContext.missingDependencies.add(descriptionFilePath);
                                                                }
                                                                return callback();
                                                        }
                                                        if (resolveContext.fileDependencies) {
                                                                resolveContext.fileDependencies.add(descriptionFilePath);
                                                        }
                                                        return onJson(err);
                                                }
                                                if (resolveContext.fileDependencies) {
                                                        resolveContext.fileDependencies.add(descriptionFilePath);
                                                }
                                                onJson(null, content);
                                        });
                                } else {
                                        resolver.fileSystem.readFile(descriptionFilePath, (err, content) => {
                                                if (err) {
                                                        if (resolveContext.missingDependencies) {
                                                                resolveContext.missingDependencies.add(descriptionFilePath);
                                                        }
                                                        return callback();
                                                }
                                                if (resolveContext.fileDependencies) {
                                                        resolveContext.fileDependencies.add(descriptionFilePath);
                                                }
                                                let json;

                                                if (content) {
                                                        try {
                                                                json = JSON.parse(content.toString());
                                                        } catch (e) {
                                                                return onJson(e);
                                                        }
                                                } else {
                                                        return onJson(new Error("No content in file"));
                                                }

                                                onJson(null, json);
                                        });
                                }

                                function onJson(err, content) {
                                        if (err) {
                                                if (resolveContext.log)
                                                        resolveContext.log(
                                                                descriptionFilePath + " (directory description file): " + err
                                                        );
                                                else
                                                        err.message =
                                                                descriptionFilePath + " (directory description file): " + err;
                                                return callback(err);
                                        }
                                        callback(null, {
                                                content,
                                                directory,
                                                path: descriptionFilePath
                                        });
                                }
                        },
                        (err, result) => {
                                if (err) return callback(err);
                                if (result) {
                                        return callback(null, result);
                                } else {
                                        const dir = cdUp(directory);
                                        if (!dir) {
                                                return callback();
                                        } else {
                                                directory = dir;
                                                return findDescriptionFile();
                                        }
                                }
                        }
                );
        })();
}

/**
 * @param {any} content content
 * @param {string|string[]} field field
 * @returns {object|string|number|boolean|undefined} field data
 */
function getField(content, field) {
        if (!content) return undefined;
        if (Array.isArray(field)) {
                let current = content;
                for (let j = 0; j < field.length; j++) {
                        if (current === null || typeof current !== "object") {
                                current = null;
                                break;
                        }
                        current = current[field[j]];
                }
                return current;
        } else {
                return content[field];
        }
}

/**
 * @param {string} directory directory
 * @returns {string|null} parent directory or null
 */
function cdUp(directory) {
        if (directory === "/") return null;
        const i = directory.lastIndexOf("/"),
                j = directory.lastIndexOf("\\");
        const p = i < 0 ? j : j < 0 ? i : i < j ? j : i;
        if (p < 0) return null;
        return directory.substr(0, p || 1);
}

exports.loadDescriptionFile = loadDescriptionFile;
exports.getField = getField;
exports.cdUp = cdUp;