From af309f2ec5e4d4dd00ded77377f1b11c4caa28d8 Mon Sep 17 00:00:00 2001
From: easing <nmailster@gmail.com>
Date: Tue, 9 Apr 2024 05:06:32 +0700
Subject: [PATCH] Fix regular expression for optional params

---
 README.md           |  2 +-
 index.js            |  6 ++++--
 package.json        |  4 ++--
 test/router.test.ts | 12 ++++++++++++
 4 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index e18fe18..d0528ee 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@
 A tiny URL router for [Nano Stores](https://github.com/nanostores/nanostores)
 state manager.
 
-* **Small.** 685 bytes (minified and brotlied). Zero dependencies.
+* **Small.** 696 bytes (minified and brotlied). Zero dependencies.
 * Good **TypeScript** support.
 * Framework agnostic. Can be used with **React**, **Preact**, **Vue**,
   **Svelte**, **Angular**, **Solid.js**, and vanilla JS.
diff --git a/index.js b/index.js
index 5a6b809..cbf9084 100644
--- a/index.js
+++ b/index.js
@@ -9,14 +9,16 @@ export function createRouter(routes, opts = {}) {
       let names = value.match(/(?<=\/:)\w+/g) || []
       let pattern = value
         .replace(/[\s!#$()+,.:<=?[\\\]^{|}]/g, '\\$&')
-        .replace(/\/\\:\w+\\\?/g, '/?([^/]*)')
+        .replace(/\/\\:\w+\\\?/g, '(?:/((?<=/)[^/]+))?')
         .replace(/\/\\:\w+/g, '/([^/]+)')
       return [
         name,
         RegExp('^' + pattern + '$', 'i'),
         (...matches) =>
           matches.reduce((params, match, index) => {
-            params[names[index]] = decodeURIComponent(match)
+            // match === undefined when nothing captured in regexp group
+            // and we swap it with empty string for backward compatibility
+            params[names[index]] = match ? decodeURIComponent(match) : ''
             return params
           }, {}),
         value
diff --git a/package.json b/package.json
index a6c9565..389f05a 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@nanostores/router",
   "version": "0.14.1",
-  "description": "A tiny (685 bytes) router for Nano Stores state manager",
+  "description": "A tiny (696 bytes) router for Nano Stores state manager",
   "keywords": [
     "nano",
     "router",
@@ -103,7 +103,7 @@
       "import": {
         "./index.js": "{ createRouter }"
       },
-      "limit": "685 B"
+      "limit": "696 B"
     }
   ],
   "clean-publish": {
diff --git a/test/router.test.ts b/test/router.test.ts
index bb8e471..b01472b 100644
--- a/test/router.test.ts
+++ b/test/router.test.ts
@@ -185,6 +185,18 @@ test('parameters can be optional', () => {
     route: 'optional',
     search: {}
   })
+
+  changePath('/profile//')
+  deepStrictEqual(router.get(), undefined)
+
+  changePath('/profile///')
+  deepStrictEqual(router.get(), undefined)
+
+  changePath('/profile-missed-route')
+  deepStrictEqual(router.get(), undefined)
+
+  changePath('/profile/10/contacts/20')
+  deepStrictEqual(router.get(), undefined)
 })
 
 test('detects URL changes', () => {