source: trip-planner-front/node_modules/enhanced-resolve/lib/util/path.js@ eed0bf8

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

"use strict";

const path = require("path");

const CHAR_HASH = "#".charCodeAt(0);
const CHAR_SLASH = "/".charCodeAt(0);
const CHAR_BACKSLASH = "\\".charCodeAt(0);
const CHAR_A = "A".charCodeAt(0);
const CHAR_Z = "Z".charCodeAt(0);
const CHAR_LOWER_A = "a".charCodeAt(0);
const CHAR_LOWER_Z = "z".charCodeAt(0);
const CHAR_DOT = ".".charCodeAt(0);
const CHAR_COLON = ":".charCodeAt(0);

const posixNormalize = path.posix.normalize;
const winNormalize = path.win32.normalize;

/**
 * @enum {number}
 */
const PathType = Object.freeze({
        Empty: 0,
        Normal: 1,
        Relative: 2,
        AbsoluteWin: 3,
        AbsolutePosix: 4,
        Internal: 5
});
exports.PathType = PathType;

/**
 * @param {string} p a path
 * @returns {PathType} type of path
 */
const getType = p => {
        switch (p.length) {
                case 0:
                        return PathType.Empty;
                case 1: {
                        const c0 = p.charCodeAt(0);
                        switch (c0) {
                                case CHAR_DOT:
                                        return PathType.Relative;
                                case CHAR_SLASH:
                                        return PathType.AbsolutePosix;
                                case CHAR_HASH:
                                        return PathType.Internal;
                        }
                        return PathType.Normal;
                }
                case 2: {
                        const c0 = p.charCodeAt(0);
                        switch (c0) {
                                case CHAR_DOT: {
                                        const c1 = p.charCodeAt(1);
                                        switch (c1) {
                                                case CHAR_DOT:
                                                case CHAR_SLASH:
                                                        return PathType.Relative;
                                        }
                                        return PathType.Normal;
                                }
                                case CHAR_SLASH:
                                        return PathType.AbsolutePosix;
                                case CHAR_HASH:
                                        return PathType.Internal;
                        }
                        const c1 = p.charCodeAt(1);
                        if (c1 === CHAR_COLON) {
                                if (
                                        (c0 >= CHAR_A && c0 <= CHAR_Z) ||
                                        (c0 >= CHAR_LOWER_A && c0 <= CHAR_LOWER_Z)
                                ) {
                                        return PathType.AbsoluteWin;
                                }
                        }
                        return PathType.Normal;
                }
        }
        const c0 = p.charCodeAt(0);
        switch (c0) {
                case CHAR_DOT: {
                        const c1 = p.charCodeAt(1);
                        switch (c1) {
                                case CHAR_SLASH:
                                        return PathType.Relative;
                                case CHAR_DOT: {
                                        const c2 = p.charCodeAt(2);
                                        if (c2 === CHAR_SLASH) return PathType.Relative;
                                        return PathType.Normal;
                                }
                        }
                        return PathType.Normal;
                }
                case CHAR_SLASH:
                        return PathType.AbsolutePosix;
                case CHAR_HASH:
                        return PathType.Internal;
        }
        const c1 = p.charCodeAt(1);
        if (c1 === CHAR_COLON) {
                const c2 = p.charCodeAt(2);
                if (
                        (c2 === CHAR_BACKSLASH || c2 === CHAR_SLASH) &&
                        ((c0 >= CHAR_A && c0 <= CHAR_Z) ||
                                (c0 >= CHAR_LOWER_A && c0 <= CHAR_LOWER_Z))
                ) {
                        return PathType.AbsoluteWin;
                }
        }
        return PathType.Normal;
};
exports.getType = getType;

/**
 * @param {string} p a path
 * @returns {string} the normalized path
 */
const normalize = p => {
        switch (getType(p)) {
                case PathType.Empty:
                        return p;
                case PathType.AbsoluteWin:
                        return winNormalize(p);
                case PathType.Relative: {
                        const r = posixNormalize(p);
                        return getType(r) === PathType.Relative ? r : `./${r}`;
                }
        }
        return posixNormalize(p);
};
exports.normalize = normalize;

/**
 * @param {string} rootPath the root path
 * @param {string | undefined} request the request path
 * @returns {string} the joined path
 */
const join = (rootPath, request) => {
        if (!request) return normalize(rootPath);
        const requestType = getType(request);
        switch (requestType) {
                case PathType.AbsolutePosix:
                        return posixNormalize(request);
                case PathType.AbsoluteWin:
                        return winNormalize(request);
        }
        switch (getType(rootPath)) {
                case PathType.Normal:
                case PathType.Relative:
                case PathType.AbsolutePosix:
                        return posixNormalize(`${rootPath}/${request}`);
                case PathType.AbsoluteWin:
                        return winNormalize(`${rootPath}\\${request}`);
        }
        switch (requestType) {
                case PathType.Empty:
                        return rootPath;
                case PathType.Relative: {
                        const r = posixNormalize(rootPath);
                        return getType(r) === PathType.Relative ? r : `./${r}`;
                }
        }
        return posixNormalize(rootPath);
};
exports.join = join;

const joinCache = new Map();

/**
 * @param {string} rootPath the root path
 * @param {string | undefined} request the request path
 * @returns {string} the joined path
 */
const cachedJoin = (rootPath, request) => {
        let cacheEntry;
        let cache = joinCache.get(rootPath);
        if (cache === undefined) {
                joinCache.set(rootPath, (cache = new Map()));
        } else {
                cacheEntry = cache.get(request);
                if (cacheEntry !== undefined) return cacheEntry;
        }
        cacheEntry = join(rootPath, request);
        cache.set(request, cacheEntry);
        return cacheEntry;
};
exports.cachedJoin = cachedJoin;

const checkExportsFieldTarget = relativePath => {
        let lastNonSlashIndex = 2;
        let slashIndex = relativePath.indexOf("/", 2);
        let cd = 0;

        while (slashIndex !== -1) {
                const folder = relativePath.slice(lastNonSlashIndex, slashIndex);

                switch (folder) {
                        case "..": {
                                cd--;
                                if (cd < 0)
                                        return new Error(
                                                `Trying to access out of package scope. Requesting ${relativePath}`
                                        );
                                break;
                        }
                        default:
                                cd++;
                                break;
                }

                lastNonSlashIndex = slashIndex + 1;
                slashIndex = relativePath.indexOf("/", lastNonSlashIndex);
        }
};
exports.checkExportsFieldTarget = checkExportsFieldTarget;