Handle null same way as undefined (#51)

- Handle `null` same way as `undefined`
- Return `null` instead of `undefined` to signal no match (BREAKING CHANGE)

CHANGELOG.md

@@ -6,6 +6,11 @@ All notable changes to this project will be documented in this file.
 
 - Add `context.redirect(path)` method to be used from inside route actions (PLANNED)
 
+### [v1.3.0] - [unreleased]
+
+- Handle `null` same way as `undefined`
+- Return `null` instead of `undefined` to signal no match. (BREAKING CHANGE)
+
 ### [v1.2.2] - 2016-05-31
 
 - Update UMD build to include missing dependencies ([#33](/~https://github.com/kriasoft/universal-router/pull/33))

docs/api.md

@@ -8,7 +8,7 @@ title: API ∙ Universal Router
 ### `resolve(routes, { path, ...context })` ⇒ `any`
 
 Traverses the list of routes in the order they are defined until it finds the first route that
-matches provided URL path string and whose action method returns anything other than `undefined`.
+matches provided URL path string and whose action method returns anything other than `null` or `undefined`.
 
 ```js
 import { resolve } from 'universal-router';

docs/getting-started.md

@@ -17,7 +17,7 @@ $ npm install universal-router --save
 
 This module contains a `resolve` function that responsible for traversing the list of routes, until it
 finds the first route matching the provided URL path string and whose action method returns anything
-other than `undefined`. Each route is just a plain JavaScript object having `path`, `action`, and
+other than `null` or `undefined`. Each route is just a plain JavaScript object having `path`, `action`, and
 `children` (optional) properties.
 
 ```js

package.json

@@ -1,7 +1,7 @@
 {
   "private": true,
   "name": "universal-router",
-  "version": "1.2.2",
+  "version": "1.3.0",
   "description": "Isomorphic router for JavaScript web applications",
   "homepage": "https://www.kriasoft.com/universal-router/",
   "repository": "kriasoft/universal-router",

src/resolve.js

@@ -14,7 +14,7 @@ async function resolve(routes, pathOrContext) {
     ? { path: pathOrContext }
     : pathOrContext;
   const root = Array.isArray(routes) ? { path: '/', children: routes } : routes;
-  let result;
+  let result = null;
   let value;
   let done = false;
 
@@ -42,7 +42,7 @@ async function resolve(routes, pathOrContext) {
       }
     }
 
-    return undefined;
+    return null;
   }
 
   context.next = next;
@@ -51,12 +51,12 @@ async function resolve(routes, pathOrContext) {
   while (!done) {
     result = await next();
 
-    if (result !== undefined) {
+    if (result !== null && result !== undefined) {
       break;
     }
   }
 
-  if (result === undefined && errorRoute) {
+  if ((result === null || result === undefined) && errorRoute) {
     context.error = new Error('Not found');
     context.error.status = 404;
     return await errorRoute.action(context, {});

test/resolve.spec.js

@@ -13,10 +13,10 @@ import { resolve } from '../src/main';
 
 describe('resolve(routes, { path, ...context })', () => {
 
-  it('should return [undefined] if a route wasn\'t not found', async () => {
+  it('should return null if a route wasn\'t not found', async () => {
     const routes = [];
     const result = await resolve(routes, '/');
-    expect(result).to.be.undefined;
+    expect(result).to.be.null;
   });
 
   it('should execute the matching route\'s action method and return its result', async () => {
@@ -30,20 +30,23 @@ describe('resolve(routes, { path, ...context })', () => {
     expect(result).to.be.equal('b');
   });
 
-  it('should find the first route whose action method !== [undefined]', async () => {
+  it('should find the first route whose action method !== undefined or null', async () => {
     const action1 = sinon.spy(() => undefined);
-    const action2 = sinon.spy(() => 'b');
-    const action3 = sinon.spy(() => 'b');
+    const action2 = sinon.spy(() => null);
+    const action3 = sinon.spy(() => 'c');
+    const action4 = sinon.spy(() => 'd');
     const routes = [
       { path: '/a', action: action1 },
       { path: '/a', action: action2 },
-      { path: '/a', action: action2 },
+      { path: '/a', action: action3 },
+      { path: '/a', action: action4 },
     ];
     const result = await resolve(routes, '/a');
-    expect(result).to.be.equal('b');
-    expect(action1.calledOnce).to.be.true;
+    expect(result).to.be.equal('c');
     expect(action1.calledOnce).to.be.true;
-    expect(action3.called).to.be.false;
+    expect(action2.calledOnce).to.be.true;
+    expect(action3.calledOnce).to.be.true;
+    expect(action4.called).to.be.false;
   });
 
   it('should be able to pass context variables to action methods', async () => {