From c7474e04798d42eb2e5a59f97fd7696be7a01c60 Mon Sep 17 00:00:00 2001
From: Artem Zakharchenko <kettanaito@gmail.com>
Date: Fri, 10 Apr 2026 23:39:15 +0200
Subject: [PATCH] fix: support ipv6 addresses

---
 src/index.ts       | 26 +++++++++++++--
 tests/ipv6.test.ts | 82 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 106 insertions(+), 2 deletions(-)
 create mode 100644 tests/ipv6.test.ts

diff --git a/src/index.ts b/src/index.ts
index bb628ee..5876d41 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -13,6 +13,8 @@ const QUESTION_MARK = 63
 const PLUS = 43
 const BACKSLASH = 92
 const UNDERSCORE = 95
+const OPEN_BRACKET = 91
+const CLOSE_BRACKET = 93
 
 const enum TokenType {
   Literal,
@@ -95,6 +97,12 @@ function parsePattern(pattern: string): Array<Token> {
   const tokens: Array<Token> = []
   let i = 0
   const length = pattern.length
+  // Tracks whether the cursor is inside a `[...]` group, used for IPv6
+  // host literals like `http://[2001:db8::1]/path`. Inside brackets,
+  // `:` and `*` are treated as literal characters so that hextets
+  // beginning with hex letters (e.g. `:db8`) are not mis-parsed as
+  // path parameters.
+  let inBrackets = false
 
   while (i < length) {
     const code = pattern.charCodeAt(i)
@@ -103,7 +111,7 @@ function parsePattern(pattern: string): Array<Token> {
       // Escaped character — consume the backslash and the next character
       // as a literal. Fall through to the literal branch below by not
       // advancing `i` here (the literal branch handles it).
-    } else if (code === ASTERISK) {
+    } else if (code === ASTERISK && !inBrackets) {
       tokens.push({
         type: TokenType.Wildcard,
         nextLiteral: undefined,
@@ -112,6 +120,7 @@ function parsePattern(pattern: string): Array<Token> {
       continue
     } else if (
       code === COLON &&
+      !inBrackets &&
       i + 1 < length &&
       isIdentStartCode(pattern.charCodeAt(i + 1))
     ) {
@@ -157,12 +166,25 @@ function parsePattern(pattern: string): Array<Token> {
         continue
       }
 
-      if (charCode === ASTERISK) {
+      if (charCode === OPEN_BRACKET) {
+        inBrackets = true
+        i++
+        continue
+      }
+
+      if (charCode === CLOSE_BRACKET) {
+        inBrackets = false
+        i++
+        continue
+      }
+
+      if (charCode === ASTERISK && !inBrackets) {
         break
       }
 
       if (
         charCode === COLON &&
+        !inBrackets &&
         i + 1 < length &&
         isIdentStartCode(pattern.charCodeAt(i + 1))
       ) {
diff --git a/tests/ipv6.test.ts b/tests/ipv6.test.ts
new file mode 100644
index 0000000..abc9352
--- /dev/null
+++ b/tests/ipv6.test.ts
@@ -0,0 +1,82 @@
+import { matchPattern, MatchResult } from '#src/index.js'
+import {
+  NO_MATCH,
+  MATCHES_WITH_PARAMS,
+  MATCHES_WITHOUT_PARAMS,
+} from '#tests/utils.js'
+
+it.each<
+  [
+    Parameters<typeof matchPattern>[0],
+    Parameters<typeof matchPattern>[1],
+    MatchResult,
+  ]
+>([
+  /* Literal IPv6 addresses */
+  ['http://[::1]/', 'http://[::1]/', MATCHES_WITHOUT_PARAMS],
+  ['http://[::1]/', new URL('http://[::1]/'), MATCHES_WITHOUT_PARAMS],
+  ['http://[::1]', new URL('http://[::1]'), MATCHES_WITHOUT_PARAMS],
+  [
+    'http://[2001:db8::1]/path',
+    'http://[2001:db8::1]/path',
+    MATCHES_WITHOUT_PARAMS,
+  ],
+  [
+    'http://[2001:db8::a1]/x',
+    'http://[2001:db8::a1]/x',
+    MATCHES_WITHOUT_PARAMS,
+  ],
+  ['http://[fe80::abcd]/', 'http://[fe80::abcd]/', MATCHES_WITHOUT_PARAMS],
+  [
+    'http://[2001:db8:85a3::8a2e:370:7334]/',
+    'http://[2001:db8:85a3::8a2e:370:7334]/',
+    MATCHES_WITHOUT_PARAMS,
+  ],
+
+  /* IPv6 with port */
+  ['http://[::1]:8080/path', 'http://[::1]:8080/path', MATCHES_WITHOUT_PARAMS],
+  [
+    'http://[::1]:*/path',
+    'http://[::1]:8080/path',
+    MATCHES_WITH_PARAMS({ '0': '8080' }),
+  ],
+
+  /* IPv6 zone identifier (URL-encoded `%`) */
+  [
+    'http://[fe80::1%25eth0]/',
+    'http://[fe80::1%25eth0]/',
+    MATCHES_WITHOUT_PARAMS,
+  ],
+
+  /* Path parameters after an IPv6 host */
+  [
+    'http://[::1]/user/:id',
+    new URL('http://[::1]/user/123'),
+    MATCHES_WITH_PARAMS({ id: '123' }),
+  ],
+  [
+    'http://[::1]/:resource/:id',
+    'http://[::1]/user/123',
+    MATCHES_WITH_PARAMS({ resource: 'user', id: '123' }),
+  ],
+  [
+    'http://[2001:db8::1]/user/:id',
+    'http://[2001:db8::1]/user/456',
+    MATCHES_WITH_PARAMS({ id: '456' }),
+  ],
+
+  /* Wildcards alongside an IPv6 host */
+  [
+    'http://[::1]/*',
+    new URL('http://[::1]/foo/bar'),
+    MATCHES_WITH_PARAMS({ '0': 'foo/bar' }),
+  ],
+  ['*://[::1]/path', 'http://[::1]/path', MATCHES_WITH_PARAMS({ '0': 'http' })],
+  ['http://*/path', 'http://[::1]/path', MATCHES_WITH_PARAMS({ '0': '[::1]' })],
+
+  /* Mismatches */
+  ['http://[::1]/path', 'http://[::2]/path', NO_MATCH],
+  ['http://[::1]/path', 'http://[::1]/other', NO_MATCH],
+])('matches %j against %j', (pattern, input, expectedResult) => {
+  expect(matchPattern(pattern, input)).toEqual(expectedResult)
+})