refactor: replace koa-router with @koajs alternative

closes #436

docs/configuration.md

@@ -648,7 +648,6 @@ expressApp.use(prefix, oidc.callback);
 ### to a koa application
 ```js
 // assumes koa ^2.0.0
-// assumes koa-router ^7.0.0
 const mount = require('koa-mount');
 const prefix = '/oidc';
 koaApp.use(mount(prefix, oidc.app));
@@ -1209,7 +1208,9 @@ This example will
       if (!allowed) {
         throw new InvalidResource('unauthorized "resource" requested');
       }
-      return transform(resourceParam, grantedResource); // => array of validated and transformed string audiences
+      // => array of validated and transformed string audiences or undefined if no audiences
+      //    are to be listed
+      return transform(resourceParam, grantedResource);
     }
   },
   formats: {

example/routes/koa.js

@@ -1,7 +1,7 @@
 const querystring = require('querystring');
 
 const bodyParser = require('koa-body');
-const Router = require('koa-router');
+const Router = require('koa-trie-router');
 
 const { renderError } = require('../../lib/helpers/defaults'); // make your own, you'll need it anyway
 const Account = require('../support/account');

example/standalone.js

@@ -56,7 +56,7 @@ let server;
     layout: '_layout',
     root: path.join(__dirname, 'views'),
   });
-  provider.use(routes(provider).routes());
+  provider.use(routes(provider).middleware());
   server = provider.listen(PORT, () => {
     console.log(`application is listening on port ${PORT}, check it's /.well-known/openid-configuration`);
   });

lib/helpers/initialize_app.js

@@ -1,6 +1,7 @@
 const assert = require('assert');
+const querystring = require('querystring');
 
-const Router = require('koa-router');
+const Router = require('koa-trie-router');
 const getCors = require('@koa/cors');
 
 const { homepage, version } = require('../../package.json');
@@ -13,12 +14,12 @@ const grants = require('../actions/grants');
 const responseModes = require('../response_modes');
 const error = require('../shared/error_handler');
 const getAuthError = require('../shared/authorization_error_handler');
-const invalidRoute = require('../shared/invalid_route');
 const contextEnsureOidc = require('../shared/context_ensure_oidc');
 
 const { InvalidRequest } = require('./errors');
 const instance = require('./weak_cache');
 const attention = require('./attention');
+const { ROUTER_URL_METHOD } = require('./symbols');
 
 const webfingerRoute = '/.well-known/webfinger';
 const discoveryRoute = '/.well-known/openid-configuration';
@@ -33,10 +34,12 @@ module.exports = function initializeApp() {
 
   const ensureOIDC = contextEnsureOidc(this);
 
+  const routeMap = new Map();
   function routerAssert(name, route, ...stack) {
     assert(typeof name === 'string' && name.charAt(0) !== '/', `invalid route name ${name}`);
     assert(typeof route === 'string' && route.charAt(0) === '/', `invalid route ${route}`);
     stack.forEach(middleware => assert.deepEqual(typeof middleware, 'function'), 'invalid middleware');
+    routeMap.set(name, route);
   }
   async function ensureSessionSave(ctx, next) {
     try {
@@ -47,25 +50,48 @@ module.exports = function initializeApp() {
       }
     }
   }
+  function namedRoute(name, ctx, next) {
+    ctx._matchedRouteName = name;
+    return next();
+  }
+
+  router[ROUTER_URL_METHOD] = function routeUrl(name, opts = {}) {
+    let path = routeMap.get(name);
+
+    if (!path) {
+      throw new Error(`No route found for name: ${name}`);
+    }
+
+    Object.entries(opts).forEach(([key, value]) => {
+      path = path.replace(`:${key}`, value);
+    });
+
+    if ('query' in opts) {
+      path = `${path}?${querystring.stringify(opts.query)}`;
+    }
+
+    return path;
+  };
+
   const get = (name, route, ...stack) => {
     routerAssert(name, route, ...stack);
-    router.get(name, route, ensureOIDC, ensureSessionSave, ...stack);
+    router.get(route, namedRoute.bind(undefined, name), ensureOIDC, ensureSessionSave, ...stack);
   };
   const post = (name, route, ...stack) => {
     routerAssert(name, route, ...stack);
-    router.post(name, route, ensureOIDC, ensureSessionSave, ...stack);
+    router.post(route, namedRoute.bind(undefined, name), ensureOIDC, ensureSessionSave, ...stack);
   };
   const del = (name, route, ...stack) => {
     routerAssert(name, route, ...stack);
-    router.del(name, route, ensureOIDC, ...stack);
+    router.del(route, namedRoute.bind(undefined, name), ensureOIDC, ...stack);
   };
   const put = (name, route, ...stack) => {
     routerAssert(name, route, ...stack);
-    router.put(name, route, ensureOIDC, ...stack);
+    router.put(route, namedRoute.bind(undefined, name), ensureOIDC, ...stack);
   };
   const options = (name, route, ...stack) => {
     routerAssert(name, route, ...stack);
-    router.options(name, route, ensureOIDC, ...stack);
+    router.options(route, namedRoute.bind(undefined, name), ensureOIDC, ...stack);
   };
 
   const { routes } = configuration;
@@ -188,7 +214,7 @@ module.exports = function initializeApp() {
     post('code_verification', routes.code_verification, error(this, 'code_verification.error'), ...codeVerification.post, ...postCodeVerification);
 
     const deviceResume = getAuthorization(this, 'device_resume');
-    get('device_resume', `${routes.code_verification}/:user_code/:grant/`, error(this, 'device_resume.error'), ...deviceResume);
+    get('device_resume', `${routes.code_verification}/:user_code/:grant`, error(this, 'device_resume.error'), ...deviceResume);
   }
 
   if (configuration.features.devInteractions) {
@@ -215,23 +241,20 @@ module.exports = function initializeApp() {
   proxyWarning.firstInternal = true;
 
   app.use(proxyWarning);
-  app.use(router.routes());
   app.use(error(this));
-  app.use(invalidRoute);
-
-  const allowedMethodsMiddleware = router.allowedMethods({
-    throw: true,
-    methodNotAllowed: () => new InvalidRequest('method not allowed', 405),
-    notImplemented: () => new InvalidRequest('not implemented', 501),
-  });
   app.use(async (ctx, next) => {
-    try {
-      await allowedMethodsMiddleware(ctx, next);
-    } catch (err) {
-      if (err.statusCode === 405) {
-        err.error_description = `method ${ctx.method} not allowed on ${ctx.path}`;
-      }
-      throw err;
+    await next();
+    if (!router.isImplementedMethod(ctx.method)) {
+      throw new InvalidRequest('not implemented', 501);
+    }
+
+    if (ctx.status === 404 && ctx.message === 'Not Found') {
+      throw new InvalidRequest('unrecognized route', 404);
+    }
+
+    if (ctx.status === 405) {
+      throw new InvalidRequest(`method ${ctx.method} not allowed on ${ctx.path}`, 405);
     }
   });
+  app.use(router.middleware());
 };

lib/helpers/symbols.js

@@ -0,0 +1,3 @@
+module.exports = {
+  ROUTER_URL_METHOD: Symbol('ROUTER_URL_METHOD'),
+};

lib/provider.js

@@ -22,6 +22,7 @@ if (HTTP2_STABLE) {
 const { DEFAULT_HTTP_OPTIONS } = require('./consts');
 const attention = require('./helpers/attention');
 const getConfiguration = require('./helpers/configuration');
+const { ROUTER_URL_METHOD } = require('./helpers/symbols');
 const instance = require('./helpers/weak_cache');
 const initializeKeystore = require('./helpers/initialize_keystore');
 const initializeAdapter = require('./helpers/initialize_adapter');
@@ -201,8 +202,7 @@ class Provider extends events.EventEmitter {
     checkInit(this);
     const { router } = instance(this);
 
-    const routerUrl = router.url(name, opts);
-    if (routerUrl instanceof Error) throw routerUrl; // specific to koa-router
+    const routerUrl = router[ROUTER_URL_METHOD](name, opts);
 
     return [mountPath, routerUrl].join('');
   }

package.json

@@ -46,7 +46,7 @@
     "got": "^9.3.2",
     "jsesc": "^2.5.2",
     "koa": "^2.6.2",
-    "koa-router": "^7.4.0",
+    "koa-trie-router": "^2.1.6",
     "lodash": "^4.17.11",
     "lru-cache": "^5.1.1",
     "nanoid": "^2.0.0",
@@ -58,22 +58,22 @@
     "uuid": "^3.3.2"
   },
   "devDependencies": {
-    "@commitlint/cli": "^7.2.1",
+    "@commitlint/cli": "^7.5.2",
     "@commitlint/config-conventional": "^7.1.2",
     "chai": "^4.2.0",
     "clear-module": "^3.0.0",
     "eslint": "^5.9.0",
     "eslint-config-airbnb-base": "^13.1.0",
     "eslint-plugin-import": "^2.14.0",
     "husky": "^1.2.0",
-    "koa-body": "^4.0.4",
+    "koa-body": "^4.0.8",
     "koa-ejs": "^4.1.2",
     "koa-helmet": "^4.0.0",
     "koa-mount": "^4.0.0",
     "mocha": "^5.2.0",
     "moment": "^2.22.2",
     "nock": "^10.0.2",
-    "nyc": "^13.1.0",
+    "nyc": "^13.3.0",
     "sinon": "^7.1.1",
     "supertest": "^3.3.0",
     "timekeeper": "^2.1.2"