Update Router API

[frenzzy]

Changes:

• Update Router API (BREAKING CHANGE)

  import Router from 'universal-router';
  const router = new Router(routes, options);
  router.resolve({ path, ...context }); // => Promise<any>
  
  // previously
  import { resolve } from 'universal-router';
  resolve(routes, { path, ...context }); // => Promise<any>

• context.next() now iterates only child routes by default (BREAKING CHANGE)
  use context.next(true) to iterate through all remaining routes
• Remove babel-runtime dependency to decrease library size (BREAKING CHANGE)
  Now you need to care about these polyfills yourself:
  • Object.assign
  • Promise
  • Map
• Rewrite matchRoute function without usage of generators to decrease amount of necessary polyfills
• Remove usage of String.prototype.startsWith(), close Fix for compatibility #81
• Add support for URL Generation, close Generate paths by name #74

  import generateUrls from 'universal-router/generateUrls';
  const url = generateUrls(router);
  url(routeName, params); // => String

• Add support for Dynamic Breadcrumbs, use context.route.parent to iterate, ref Example of breadcrumbs? #36
• Add support for Declarative Routes, close Add support for declarative routes #67

  const router = new Router(routes, { resolveRoute: customResolveRouteFn });

• Add support for Base URL option

  const router = new Router(routes, { baseUrl: '/base' });

• Add ability to specify custom context property once

  const router = new Router(routes, { context: { store: createStore(), ... } });

• Add context.url with the original url passed to resolve method, close context.path gets overwritten by route.path while resolving #69
• Add context property to Route not found error, close On 404 error stack trace is not showing 404 urls. #45

Examples:

import Router from 'universal-router';


import generateUrls from 'universal-router/generateUrls';

 // optional

// route example
const route = {

  path: '/post/:title',           // string, required

  name: 'post',                   // unique string, optional

  parent: null,                   // route or null, optional (filled by router)

  children: [],                   // array of routes or null, optional

  action(context, params) {       // function, optional

    // action method should return anything except `null` or `undefined`
    // to be resolved by router, otherwise router will throw an error
    // if all matched routes returned nothing
    return null;
  }

};


// just array of routes
const routes = [
  { path: '/' },
  { path: '/hello', name: 'hello' },
  { path: '/example', action() {
    return 'Page';
  } },
];

// context object which router supplements and transmits to each route
const context = {
  // your params here

  // plus params filled by the router
  router,                         // current router instance
  route,                          // matched route object
  next,                           // middleware function which can continue resolving
  url: '/base/post/welcome',      // url which was transmitted via router.resolve()
  baseUrl: '/base',               // base url relative to current route
  path: '/post/welcome',          // matched path
  params: { title: 'welcome' },   // matched params
  keys: [{ name: 'title', ... }], // an array of keys found in the path
};

// default router options

const options = {

  // you can add anything to the context object
  // right when you create a router instance
  // for example `context: { store: createStore() }`

  context,


  // you may define Base URL if your site lives in subfolder
  // like `https://kriasoft.github.io/universal-router/*`
  // baseUrl: '/universal-router'
  baseUrl: '',

  // you can redefine `resolveRoute` function to be able to work with your
  // routes in declarative manner or for any custom route handling logic
  // by default router calls `action` method of matched routes if any
  resolveRoute(context, params) {

    if (typeof context.route.action === 'function') {

      context.route.action(context, params);
    }
    return null;
  },
};



// new constructor based router api
const router = new Router(routes, options);
// or just new Router(route);



// url generation
const url = generateUrls(router);
const routeName = 'post';


const params = { title: 'welcome' };

url(routeName, params);              // => '/post/welcome'

url('world');                        // => '/hello/world'



// resolving routes
const path = '/base/post/welcome';

router.resolve({ path, ...context }) // => Promise<Any>
router.resolve('/example')           // => Promise => 'Page'
router.resolve('/random')            // => Promise
 => Error('Page not found')

[coveralls]

Coverage remained the same at 100.0% when pulling 814f670 on frenzzy:next into ee588b2 on kriasoft:master.