index.js

/*
 * Wayne - Server Worker Routing library (v. 0.16.5)
 *
 * Copyright (c) 2022-2024 Jakub T. Jankiewicz <https://jcubic.pl/me>
 * Released under MIT license
 */

const root_url = get_root_path();
const root_url_re = new RegExp('^' + escape_re(root_url));

function same_origin(origin) {
    return origin === self.location.origin;
}

function get_root_path() {
    if (self.registration) {
        const url = new URL(registration.scope);
        return url.pathname.replace(/\/$/, '');
    }
    return location.pathname.replace(/\/[^\/]+$/, '');
}

function normalize_url(url) {
    return url.replace(root_url_re, '');
}

function escape_re(str) {
    if (typeof str == 'string') {
        var special = /([\^\$\[\]\(\)\{\}\+\*\.\|\?])/g;
        return str.replace(special, '\\$1');
    }
}

function is_function(arg) {
    return typeof arg === 'function';
}

function is_promise(arg) {
    return arg && typeof arg === 'object' && is_function(arg.then);
}

// taken from Isomorphic-git MIT license
function isPromiseFs(fs) {
    const test = targetFs => {
        try {
            // If readFile returns a promise then we can probably assume the other
            // commands do as well
            return targetFs.readFile().catch(e => e)
        } catch (e) {
            return e
        }
    }
    return is_promise(test(fs));
}
// List of commands all filesystems are expected to provide
const commands = [
    'stat',
    'readdir',
    'readFile'
];

function bind_fs(fs) {
    const result = {};
    if (isPromiseFs(fs)) {
        for (const command of commands) {
            result[command] = fs[command].bind(fs);
        }
    } else {
        for (const command of commands) {
            result[command] = function(...args) {
                return new Promise((resolve, reject) => {
                    fs[command](...args, function(err, data) {
                        if (err) {
                            reject(err);
                        } else {
                            resolve(data);
                        }
                    });
                });
            };
        }
    }
    return result;
}

// -----------------------------------------------------------------------------
// :: Wayne Route Response Class
// -----------------------------------------------------------------------------

export class HTTPResponse {
    constructor(resolve, reject) {
        this._resolve = resolve;
        this._reject = reject;
    }
    html(data, init) {
        this.send(data, { type: 'text/html', ...init });
    }
    text(data, init) {
        this.send(data, init);
    }
    json(data, init) {
        this.send(JSON.stringify(data), { type: 'application/json', ...init });
    }
    blob(blob, init = {}) {
        this._resolve(new Response(blob, init));
    }
    send(data, { type = 'text/plain', ...init } = {}) {
        if (![undefined, null].includes(data)) {
            data = new Blob([data], {
                type
            });
        }
        this.blob(data, init);
    }
    async fetch(arg) {
        if (typeof arg === 'string') {
            const _res = await fetch(arg);
            const type = _res.headers.get('Content-Type') ?? 'application/octet-stream';
            this.send(await _res.arrayBuffer(), { type });
        } else if (arg instanceof Request) {
            return fetch(arg).then(this._resolve).catch(this._reject);
        }
    }
    download(content, { filename = 'download', type = 'text/plain', ...init } = {}) {
        const headers = {
            'Content-Disposition': `attachment; filename="${filename}"`
        };
        this.send(content, { type, headers, ...init });
    }
    redirect(code, url) {
        if (url === undefined) {
            url = code;
            code = 302;
        }
        if (!url.match(/https?:\/\//)) {
            url = root_url + url;
        }
        this._resolve(Response.redirect(url, code));
    }
    sse({ onClose } = {}) {
        let send, close, stream, defunct;
        stream = new ReadableStream({
            cancel() {
                defunct = true;
                trigger(onClose);
            },
            start: controller => {
                send = function(event) {
                    if (!defunct) {
                        const chunk = createChunk(event);
                        const payload = new TextEncoder().encode(chunk);
                        controller.enqueue(payload);
                    }
                };
                close = function close() {
                    controller.close();
                    stream = null;
                    trigger(onClose);
                };
            }
        });
        this._resolve(new Response(stream, {
            headers: {
                'Content-Type': 'text/event-stream; charset=utf-8',
                'Transfer-Encoding': 'chunked',
                'Connection': 'keep-alive'
            }
        }));
        return {
            send,
            close
        };
    }
}


// -----------------------------------------------------------------------------
// :: Route Parser
// :: code based on https://github.com/jcubic/route.js
// :: Copyright (C) 2014-2017 Jakub T. Jankiewicz <https://jcubic.pl/me>
// -----------------------------------------------------------------------------
export function RouteParser() {
    const name_re = '[a-zA-Z_][a-zA-Z_0-9]*';
    const self = this;
    const open_tag = '{';
    const close_tag = '}';
    const glob = '*';
    const number = '\\d';
    const optional = '?';
    const open_group = '(';
    const close_group = ')';
    const plus = '+';
    const dot = '.';
    self.route_parser = function(open, close) {

        const routes = {};
        const tag_re = new RegExp('(' + escape_re(open) + name_re + escape_re(close) + ')', 'g');
        const tokenizer_re = new RegExp(['(', escape_re(open), name_re, escape_re(close), '|',
                                         escape_re(glob), '|', escape_re(number), '|', escape_re(dot), '|',
                                         escape_re(optional), '|', escape_re(open_group), '|',
                                         escape_re(close_group), '|', escape_re(plus), ')'].join(''), 'g');
        const clear_re = new RegExp(escape_re(open) + '(' + name_re + ')' +
                                    escape_re(close), 'g');
        return function(str) {
            const result = [];
            let index = 0;
            let parentheses = 0;
            str = str.split(tokenizer_re).map(function(chunk, i, chunks) {
                if (chunk === open_group) {
                    parentheses++;
                } else if (chunk === close_group) {
                    parentheses--;
                }
                if ([open_group, plus, close_group, optional, dot, number].includes(chunk)) {
                    return chunk;
                } else if (chunk === glob) {
                    result.push(index++);
                    return '(.*?)';
                } else if (chunk.match(tag_re)) {
                    result.push(chunk.replace(clear_re, '$1'));
                    return '([^\\/]+)';
                } else {
                    return chunk;
                }
            }).join('');
            if (parentheses !== 0) {
                throw new Error(`Wayne: Unbalanced parentheses in an expression: ${str}`);
            }
            return {re: str, names: result};
        };
    };
    const parse = self.route_parser(open_tag, close_tag);
    self.parse = parse;
    self.pick = function(routes, url, origin) {
        let input;
        let keys;
        if (routes instanceof Array) {
            input = {};
            keys = routes;
            routes.map(function(route) {
                input[route] = route;
            });
        } else {
            keys = Object.keys(routes);
            input = routes;
        }
        const results = [];
        for (let i=keys.length; i--;) {
            const key = keys[i];
            let pattern;
            // check if origin match for full URL
            if (key.match(/:\/\//)) {
                const url = new URL(key);
                if (url.origin !== origin) {
                    continue;
                }
                pattern = key.replace(url.origin, '');
            } else if (!same_origin(origin)) {
                // skip different origin
                continue;
            } else {
                pattern = key;
            }
            const parts = parse(pattern);
            const m = url.match(new RegExp('^' + parts.re + '$'));
            if (m) {
                const matched = m.slice(1);
                const data = {};
                if (matched.length) {
                    parts.names.forEach((name, i) => {
                        data[name] = matched[i];
                    });
                }
                results.push({
                    pattern: key,
                    data
                });
            }
        }
        return results;
    };
}

function html(content) {
    return [
        '<!DOCTYPE html>',
        '<html>',
        '<head>',
        '<meta charset="UTF-8">',
        '<title>Wayne Service Worker</title>',
        '</head>',
        '<body>',
        ...content,
        '</body>',
        '</html>'
    ].join('\n');
}

function error500(error) {
    var output = html([
        '<h1>Wayne: 500 Server Error</h1>',
        '<p>Service worker give 500 error</p>',
        `<p>${error.message || error}</p>`,
        `<pre>${error.stack || ''}</pre>`
    ]);
    return [output, {
        status: 500,
        statusText: '500 Server Error'
    }];
}

function dir(prefix, path, list) {
    var output = html([
        '<h1>Wayne</h1>',
        `<p>Content of ${path}</p>`,
        '<ul>',
        ...list.map(name => {
            return `<li><a href="${root_url}${prefix}${path}${name}">${name}</a></li>`;
        }),
        '</ul>'
    ]);
    return [output, {
        status: 404,
        statusText: '404 Page Not Found'
    }];
}

function error404(path) {
    var output = html([
        '<h1>Wayne: 404 File Not Found</h1>',
        `<p>File ${path} not found`
    ]);
    return [output, {
        status: 404,
        statusText: '404 Page Not Found'
    }];
}

function createChunk({ data, event, retry, id }) {
    return Object.entries({ event, id, data, retry })
        .filter(([, value]) => value)
        .map(([key, value]) => `${key}: ${value}`)
        .join('\n') + '\n\n';
}

function trigger(maybeFn, ...args) {
    if (typeof maybeFn === 'function') {
        maybeFn(...args);
    }
}

function chain_handlers(handlers, callback) {
    if (handlers.length) {
        return new Promise((resolve, reject) => {
            let i = 0;
            (async function recur() {
                const handler = handlers[i];
                if (!handler) {
                    return resolve();
                }
                try {
                    await callback(handler, function next() {
                        i++
                        recur();
                    });
                } catch(error) {
                    reject(error);
                }
            })();
        });
    }
}

async function list_dir({ fs, path }, path_name) {
    const names = await fs.readdir(path_name);
    return Promise.all(names.map(async name => {
        const fullname = path.join(path_name, name);
        const stat = await fs.stat(fullname);
        if (stat.isDirectory()) {
            return `${name}/`;
        }
        return name;
    }));
}

// -----------------------------------------------------------------------------
// :: File System
// -----------------------------------------------------------------------------

export function FileSystem(options) {
    let {
        path,
        prefix = '',
        test,
        dir = () => '/',
        fs,
        mime,
        default_file = 'index.html'
    } = options;

    fs = bind_fs(fs);
    const parser = new RouteParser();
    if (prefix && !prefix.startsWith('/')) {
        prefix = `/${prefix}`;
    }
    if (!test) {
        test = url => url.pathname.startsWith(prefix);
    }
    async function serve(res, path_name) {
        const ext = path.extname(path_name);
        const type = mime.getType(ext);
        const data = await fs.readFile(path_name);
        res.send(data, { type });
    }
    return async function(req, res, next) {
        const method = req.method;
        const url = new URL(req.url);
        let path_name = normalize_url(decodeURIComponent(url.pathname));
        url.pathname = path_name;
        if (!(same_origin(url.origin) && await test(url))) {
            return next();
        }
        if (req.method !== 'GET') {
            return res.send('Method Not Allowed', { status: 405 });
        }
        if (prefix) {
            path_name = path_name.substring(prefix.length);
        }
        if (!path_name) {
            path_name = '/';
        }
        path_name = path.join(await dir(), path_name);
        try {
            const stat = await fs.stat(path_name);

            if (stat.isFile()) {
                await serve(res, path_name);
            } else if (stat.isDirectory()) {
                const default_path = path.join(path_name, default_file)
                const stat = await fs.stat(default_path);
                if (stat.isFile()) {
                    await serve(res, default_path);
                } else {
                    res.html(...dir(
                        prefix,
                        path_name,
                        await list_dir({ fs, path }, path_name)
                    ));
                }
            }
        } catch(e) {
            console.log(e.stack);
            if (typeof stat === 'undefined') {
                res.html(...error404(path_name));
            } else {
                res.html(...error500(error));
            }
        }
    };
}

// -----------------------------------------------------------------------------
// :: Main Wayne Constructor
// -----------------------------------------------------------------------------

export class Wayne {
    constructor({ filter = () => true } = {}) {
        this._er_handlers = [];
        this._middlewares = [];
        this._routes = {};
        this._timeout = 5 * 60 * 1000; // 5 minutes
        this._parser = new RouteParser();
        self.addEventListener('fetch', (event) => {
            if (filter(event.request) === false) {
                return;
            }
            const promise = new Promise(async (resolve, reject) => {
                const req = event.request;
                try {
                    const res = new HTTPResponse(resolve, reject);
                    await chain_handlers(this._middlewares, function(fn, next) {
                        return fn(req, res, next);
                    });
                    const method = req.method;
                    const url = new URL(req.url);
                    const path = normalize_url(url.pathname);
                    const origin = url.origin;
                    const routes = this._routes[method];
                    if (routes) {
                        const match = this._parser.pick(routes, path, origin);
                        const have_wildcard = match.length > 1 && match.find(route => {
                            return !!route.pattern.match(/\*/);
                        });
                        if (match.length) {
                            let selected_route;
                            if (have_wildcard) {
                                selected_route = match.find(route => {
                                    return !route.pattern.match(/\*/);
                                });
                            }
                            if (!(have_wildcard && selected_route)) {
                                selected_route = match[0];
                            }
                            const fns = [...this._middlewares, ...routes[selected_route.pattern]];
                            req.params = selected_route.data;
                            setTimeout(function() {
                                reject('Timeout Error');
                            }, this._timeout);
                            await chain_handlers(fns, (fn, next) => {
                                return fn(req, res, next);
                            });
                            return;
                        }
                    }
                    if (event.request.cache === 'only-if-cached' && event.request.mode !== 'same-origin') {
                        return;
                    }
                    fetch(event.request).then(resolve).catch(reject);
                } catch(error) {
                    this._handle_error(resolve, req, error);
                }
            });
            event.respondWith(promise.catch(() => {}));
        });
        ['GET', 'POST', 'DELETE', 'PATCH', 'PUT'].forEach(method => {
            this[method.toLowerCase()] = this.method(method);
        });
    }
    _handle_error(resolve, req, error) {
        const res = new HTTPResponse(resolve);
        if (this._er_handlers.length) {
            chain_handlers(this._er_handlers, function(handler, next) {
                handler(error, req, res, next);
            }, function(error) {
                res.html(...error500(error));
            });
        } else {
            res.html(...error500(error));
        }
    }
    use(...fns) {
        fns.forEach(fn => {
            if (typeof fn === 'function') {
                if (fn.length === 4) {
                    this._er_handlers.push(fn);
                } else if (fn.length === 3) {
                    this._middlewares.push(fn);
                }
            }
        });
    }
    method(method) {
        return function(url, fn) {
            if (!this._routes[method]) {
                this._routes[method] = {};
            }
            const routes = this._routes[method];
            if (!routes[url]) {
                routes[url] = [];
            }
            routes[url].push(fn);
            return this;
        };
    }
}

// -----------------------------------------------------------------------------
// :: RPC
// -----------------------------------------------------------------------------

export function rpc(channel, methods) {
    channel.addEventListener('message', async function handler(message) {
        if (Object.keys(message.data).includes('method', 'id', 'args')) {
            const { method, id, args } = message.data;
            try {
                const result = await methods[method](...args);
                channel.postMessage({id, result});
            } catch(error) {
                channel.postMessage({id, error});
            }
        }
    });
};

let rpc_id = 0;

export function send(channel, method, args) {
    return new Promise((resolve, reject) => {
        const id = ++rpc_id;
        const payload = { id, method, args };
        channel.addEventListener('message', function handler(message) {
            if (id == message.data.id) {
                const data = message.data;
                channel.removeEventListener('message', handler);
                if (data.error) {
                    reject(data.error);
                } else {
                    resolve(message.data);
                }
            }
        });
        channel.postMessage(payload);
    });
};