v1.1.1

Author: lpil

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## v1.1.1 - 2025-04-06
+
+- Fixed a bug where JavaScript regexp's internal mutable state would not get
+  reset, resulting in incorrect results for certain sequences of operations.
+
 ## v1.1.0 - 2025-02-05
 
 - Added the `match_map` function.

gleam.toml

@@ -1,5 +1,5 @@
 name = "gleam_regexp"
-version = "1.1.0"
+version = "1.1.1"
 gleam = ">= 1.0.0"
 licences = ["Apache-2.0"]
 description = "Regular expressions in Gleam!"

src/gleam_regexp_ffi.mjs

@@ -29,6 +29,7 @@ export function split(regex, string) {
 }
 
 export function scan(regex, string) {
+  regex.lastIndex = 0;
   const matches = Array.from(string.matchAll(regex)).map((match) => {
     const content = match[0];
     return new RegexMatch(content, submatches(match.slice(1)));
@@ -37,10 +38,12 @@ export function scan(regex, string) {
 }
 
 export function replace(regex, original_string, replacement) {
+  regex.lastIndex = 0;
   return original_string.replaceAll(regex, replacement);
 }
 
 export function match_map(regex, original_string, replacement) {
+  regex.lastIndex = 0;
   let replace = (match, ...args) => {
     const hasNamedGroups = typeof args.at(-1) === "object";
     const groups = args.slice(0, hasNamedGroups ? -3 : -2);

test/gleam_regexp_test.gleam

@@ -218,3 +218,11 @@ pub fn match_map_1_test() {
   regexp.match_map(re, "'1', '2', '3', '4'", replace)
   |> should.equal("one, two, three, '4'")
 }
+
+// https://github.com/gleam-lang/regexp/issues/4
+pub fn last_index_bug_test() {
+  let assert Ok(re) = regexp.from_string("(b)")
+  let assert [Match("b", [Some("b")])] = regexp.scan(re, "b")
+  let assert True = regexp.check(re, "b")
+  let assert [Match("b", [Some("b")])] = regexp.scan(re, "b")
+}