altmetric · jbilbo · Jan 29, 2026 · Jan 29, 2026 · Jan 29, 2026 · Jan 29, 2026
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
@@ -0,0 +1,30 @@
+name: Tests
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        php: ['7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3']
+
+    name: PHP ${{ matrix.php }}
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php }}
+          coverage: none
+
+      - name: Install dependencies
+        run: composer install --prefer-dist --no-progress
+
+      - name: Run tests
+        run: vendor/bin/phpunit
diff --git a/.gitignore b/.gitignore
@@ -1,2 +1,3 @@
 composer.lock
 vendor
+.phpunit.result.cache
diff --git a/.travis.yml b/.travis.yml
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -2,6 +2,15 @@
 All notable changes to this project will be documented in this file. This
 project adheres to [Semantic Versioning](http://semver.org/).
 
+## [1.0.0] - 2026-01-29
+### Changed
+- Minimum PHP version is now 7.2 (previously 5.4)
+- Migrate CI from Travis to GitHub Actions
+- Add type hints to all `extract()` methods (`?string` parameter, `array` return)
+
+### Security
+- Upgrade PHPUnit to 8.5.52 to fix unsafe deserialization vulnerability
+
 ## [0.10.1] - 2018-04-09
 ### Fixed
 - Restored support for extracting hyphenated ISBN-10s with registration group
@@ -81,4 +90,5 @@ project adheres to [Semantic Versioning](http://semver.org/).
 [0.8.0]: https://github.com/altmetric/php-identifiers/releases/tag/v0.8.0
 [0.9.0]: https://github.com/altmetric/php-identifiers/releases/tag/v0.9.0
 [0.10.0]: https://github.com/altmetric/php-identifiers/releases/tag/v0.10.0
+[1.0.0]: https://github.com/altmetric/php-identifiers/releases/tag/v1.0.0
 [0.10.1]: https://github.com/altmetric/php-identifiers/releases/tag/v0.10.1
diff --git a/LICENSE b/LICENSE
@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2016-2017 Altmetric LLP
+Copyright (c) 2016-2026 Altmetric LLP
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

diff --git a/README.md b/README.md
@@ -1,10 +1,10 @@
-# Identifiers [![Build Status](https://travis-ci.org/altmetric/php-identifiers.svg?branch=master)](https://travis-ci.org/altmetric/php-identifiers)
+# Identifiers [![Tests](https://github.com/altmetric/php-identifiers/actions/workflows/tests.yml/badge.svg)](https://github.com/altmetric/php-identifiers/actions/workflows/tests.yml)
 
 Collection of utilities related to the extraction, validation and normalization
 of various scholarly identifiers.
 
-**Current version:** 0.10.1  
-**Supported PHP versions:** 5.4, 5.5, 5.6, 7
+**Current version:** 1.0.0
+**Supported PHP versions:** 7.2+
 
 ## Installation
 
@@ -161,6 +161,6 @@ We also maintain [a version of this library for Ruby](https://github.com/altmetr
 
 ## License
 
-Copyright © 2016-2017 Altmetric LLP
+Copyright © 2016-2026 Altmetric LLP
 
 Distributed under the [MIT License](http://opensource.org/licenses/MIT).
diff --git a/composer.json b/composer.json
@@ -15,10 +15,10 @@
         }
     ],
     "require": {
-        "php": ">= 5.4.0"
+        "php": ">= 7.2"
     },
     "require-dev": {
-        "phpunit/phpunit": "^4.8"
+        "phpunit/phpunit": "^8.5.52"
     },
     "suggest": {
         "ext-mbstring": "Needed for multibyte string support (alternatively, require symfony/polyfill-mbstring)"

diff --git a/phpunit.xml b/phpunit.xml
@@ -1,6 +1,6 @@
 <phpunit colors="true" bootstrap="vendor/autoload.php">
   <testsuites>
-    <testsuite>
+    <testsuite name="Identifiers">
       <directory>tests</directory>
     </testsuite>
   </testsuites>

diff --git a/src/AdsBibcode.php b/src/AdsBibcode.php
@@ -3,8 +3,9 @@
 
 class AdsBibcode
 {
-    public static function extract($str)
+    public static function extract(?string $str): array
     {
+        $str = $str ?? '';
         preg_match_all('/\b\d{4}[a-z][0-9a-z&.]{14}\b/ui', $str, $matches);
 
         return $matches[0];

diff --git a/src/ArxivId.php b/src/ArxivId.php
@@ -29,8 +29,10 @@ class ArxivId
 }xiu
 EOT;
 
-    public static function extract($str)
+    public static function extract(?string $str): array
     {
+        $str = $str ?? '';
+
         return array_merge(self::extractPre2007ArxivIds($str), self::extractPost2007ArxivIds($str));
     }
 

diff --git a/src/Doi.php b/src/Doi.php
@@ -32,8 +32,9 @@ class Doi
 }xu
 EOT;
 
-    public static function extract($str)
+    public static function extract(?string $str): array
     {
+        $str = $str ?? '';
         preg_match_all(self::REGEXP, mb_strtolower($str, 'UTF-8'), $matches);
 
         return $matches[0];

diff --git a/src/Handle.php b/src/Handle.php
@@ -3,8 +3,9 @@
 
 class Handle
 {
-    public static function extract($str)
+    public static function extract(?string $str): array
     {
+        $str = $str ?? '';
         preg_match_all('#\b[\d.]+/\S+\b#u', $str, $matches);
 
         return $matches[0];

diff --git a/src/Isbn.php b/src/Isbn.php
@@ -48,8 +48,10 @@ class Isbn
 }xu
 EOT;
 
-    public static function extract($str)
+    public static function extract(?string $str): array
     {
+        $str = $str ?? '';
+
         return array_merge(self::extractIsbnAs($str), self::extractIsbn13s($str), self::extractIsbn10s($str));
     }
 
@@ -123,9 +125,9 @@ private static function stripHyphenation($match, $limit)
         return $isbn;
     }
 
-    private static function isValidIsbn13($str)
+    private static function isValidIsbn13(?string $str): bool
     {
-        if (strlen($str) !== 13) {
+        if ($str === null || strlen($str) !== 13) {
             return false;
         }
 
@@ -134,9 +136,9 @@ private static function isValidIsbn13($str)
         return $checkDigit === (int) $str[12];
     }
 
-    private static function isValidIsbn10($str)
+    private static function isValidIsbn10(?string $str): bool
     {
-        if (strlen($str) !== 10) {
+        if ($str === null || strlen($str) !== 10) {
             return false;
         }
 

diff --git a/src/NationalClinicalTrialId.php b/src/NationalClinicalTrialId.php
@@ -3,8 +3,9 @@
 
 class NationalClinicalTrialId
 {
-    public static function extract($str)
+    public static function extract(?string $str): array
     {
+        $str = $str ?? '';
         preg_match_all('/\bNCT\d+\b/ui', $str, $matches);
 
         return array_map('strtoupper', $matches[0]);

diff --git a/src/OrcidId.php b/src/OrcidId.php
@@ -4,8 +4,9 @@
 
 class OrcidId
 {
-    public static function extract($str)
+    public static function extract(?string $str): array
     {
+        $str = $str ?? '';
         preg_match_all('/\d{4}-\d{4}-\d{4}-\d{3}[\dX]/i', $str, $matches);
 
         return array_filter(array_map('strtoupper', $matches[0]), [__CLASS__, 'isValid']);

diff --git a/src/PubmedId.php b/src/PubmedId.php
@@ -38,8 +38,10 @@ class PubmedId
 }xu
 EOT;
 
-    public static function extract($str)
+    public static function extract(?string $str): array
     {
+        $str = $str ?? '';
+
         return array_merge(self::extractPubmedIds($str), self::extractPubmedUris($str));
     }
 

diff --git a/src/RepecId.php b/src/RepecId.php
@@ -3,8 +3,9 @@
 
 class RepecId
 {
-    public static function extract($str)
+    public static function extract(?string $str): array
     {
+        $str = $str ?? '';
         preg_match_all('/\brepec:\S+\b/ui', $str, $matches);
 
         return array_map(

diff --git a/src/Uri.php b/src/Uri.php
@@ -52,8 +52,9 @@ class Uri
 #x
 EOF;
 
-    public static function extract($str)
+    public static function extract(?string $str): array
     {
+        $str = $str ?? '';
         preg_match_all(self::REGEXP, $str, $matches);
 
         return $matches[0];

diff --git a/src/Urn.php b/src/Urn.php
@@ -3,8 +3,9 @@
 
 class Urn
 {
-    public static function extract($str)
+    public static function extract(?string $str): array
     {
+        $str = $str ?? '';
         preg_match_all(
             '/\burn:(?!urn:)[a-z0-9][a-z0-9\-]{1,31}:(?:[a-z0-9()+,-.:=@;$_!*\']|' .
             '%(?:2[1-9a-f]|[3-6][0-9a-f]|7[0-9a-e]))+/i',

diff --git a/tests/AdsBibcodeTest.php b/tests/AdsBibcodeTest.php
@@ -1,7 +1,7 @@
 <?php
 namespace Altmetric\Identifiers;
 
-class AdsBibcodeTest extends \PHPUnit_Framework_TestCase
+class AdsBibcodeTest extends \PHPUnit\Framework\TestCase
 {
     public function testExtractsBibcodes()
     {

diff --git a/tests/ArxivIdTest.php b/tests/ArxivIdTest.php
@@ -1,7 +1,7 @@
 <?php
 namespace Altmetric\Identifiers;
 
-class ArxivIdTest extends \PHPUnit_Framework_TestCase
+class ArxivIdTest extends \PHPUnit\Framework\TestCase
 {
     public function testExtractsPre2007ArxivIds()
     {

diff --git a/tests/DoiTest.php b/tests/DoiTest.php
@@ -1,7 +1,7 @@
 <?php
 namespace Altmetric\Identifiers;
 
-class DoiTest extends \PHPUnit_Framework_TestCase
+class DoiTest extends \PHPUnit\Framework\TestCase
 {
     public function testExtractsDois()
     {

diff --git a/tests/HandleTest.php b/tests/HandleTest.php
@@ -1,7 +1,7 @@
 <?php
 namespace Altmetric\Identifiers;
 
-class HandleTest extends \PHPUnit_Framework_TestCase
+class HandleTest extends \PHPUnit\Framework\TestCase
 {
     public function testExtractsHandles()
     {

diff --git a/tests/IsbnTest.php b/tests/IsbnTest.php
@@ -1,7 +1,7 @@
 <?php
 namespace Altmetric\Identifiers;
 
-class IsbnTest extends \PHPUnit_Framework_TestCase
+class IsbnTest extends \PHPUnit\Framework\TestCase
 {
     public function testExtractsIsbn13s()
     {

diff --git a/tests/NationalClinicalTrialIdTest.php b/tests/NationalClinicalTrialIdTest.php
@@ -1,7 +1,7 @@
 <?php
 namespace Altmetric\Identifiers;
 
-class NationalClinicalTrialIdTest extends \PHPUnit_Framework_TestCase
+class NationalClinicalTrialIdTest extends \PHPUnit\Framework\TestCase
 {
     public function testExtractsNctIds()
     {

diff --git a/tests/OrcidIdTest.php b/tests/OrcidIdTest.php
@@ -1,7 +1,7 @@
 <?php
 namespace Altmetric\Identifiers;
 
-class OrcidIdTest extends \PHPUnit_Framework_TestCase
+class OrcidIdTest extends \PHPUnit\Framework\TestCase
 {
     public function testExtractsOrcids()
     {

diff --git a/tests/PubmedIdTest.php b/tests/PubmedIdTest.php
@@ -1,7 +1,7 @@
 <?php
 namespace Altmetric\Identifiers;
 
-class PubmedIdTest extends \PHPUnit_Framework_TestCase
+class PubmedIdTest extends \PHPUnit\Framework\TestCase
 {
     public function testExtractsPubmedIDs()
     {

diff --git a/tests/RepecIdTest.php b/tests/RepecIdTest.php
@@ -1,7 +1,7 @@
 <?php
 namespace Altmetric\Identifiers;
 
-class RepecIdTest extends \PHPUnit_Framework_TestCase
+class RepecIdTest extends \PHPUnit\Framework\TestCase
 {
     public function testExtractsRepecIds()
     {

diff --git a/tests/UriTest.php b/tests/UriTest.php
@@ -1,7 +1,7 @@
 <?php
 namespace Altmetric\Identifiers;
 
-class UriTest extends \PHPUnit_Framework_TestCase
+class UriTest extends \PHPUnit\Framework\TestCase
 {
     public function testExtractsValidUris()
     {

diff --git a/tests/UrnTest.php b/tests/UrnTest.php
@@ -1,7 +1,7 @@
 <?php
 namespace Altmetric\Identifiers;
 
-class UrnTest extends \PHPUnit_Framework_TestCase
+class UrnTest extends \PHPUnit\Framework\TestCase
 {
     public function testExtractsValidUrns()
     {