From 8fa223b1afb12e808ad1bc2a9cb1f94c3a07500c Mon Sep 17 00:00:00 2001
From: Chris Smith <chris.smith@widerplan.com>
Date: Mon, 9 Aug 2021 10:42:17 +0100
Subject: [PATCH 1/2] Fix soft BC break of Uuid::fromString()

Uses an assertion to indicate the `$uuid` variable cannot be an empty
string, satisfying docblock on `LazyUuidFromString`.
---
 src/Uuid.php | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/Uuid.php b/src/Uuid.php
index dd690e1..d80fd57 100644
--- a/src/Uuid.php
+++ b/src/Uuid.php
@@ -24,6 +24,7 @@ use Ramsey\Uuid\Rfc4122\FieldsInterface as Rfc4122FieldsInterface;
 use Ramsey\Uuid\Type\Hexadecimal;
 use Ramsey\Uuid\Type\Integer as IntegerObject;
 
+use function assert;
 use function bin2hex;
 use function preg_match;
 use function str_replace;
@@ -436,7 +437,7 @@ class Uuid implements UuidInterface
     /**
      * Creates a UUID from the string standard representation
      *
-     * @param non-empty-string $uuid A hexadecimal string
+     * @param string $uuid A hexadecimal string
      *
      * @return UuidInterface A UuidInterface instance created from a hexadecimal
      *     string representation
@@ -452,6 +453,8 @@ class Uuid implements UuidInterface
     public static function fromString(string $uuid): UuidInterface
     {
         if (! self::$factoryReplaced && preg_match(LazyUuidFromString::VALID_REGEX, $uuid) === 1) {
+            assert($uuid !== '');
+
             return new LazyUuidFromString(strtolower($uuid));
         }
 

From ef1eb74c82a4acbccce9e45b3795c94ff7e122c5 Mon Sep 17 00:00:00 2001
From: Chris Smith <chris.smith@widerplan.com>
Date: Mon, 9 Aug 2021 12:55:31 +0100
Subject: [PATCH 2/2] Add test covering `Uuid::fromString()` being called with
 empty string

---
 tests/UuidTest.php | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tests/UuidTest.php b/tests/UuidTest.php
index 034189b..29f1761 100644
--- a/tests/UuidTest.php
+++ b/tests/UuidTest.php
@@ -124,6 +124,14 @@ class UuidTest extends TestCase
         $this->assertSame('ff6f8cb0-c57d-11e1-9b21-0800200c9a66', $uuid->toString());
     }
 
+    public function testFromStringWithEmptyString(): void
+    {
+        $this->expectException(InvalidUuidStringException::class);
+        $this->expectExceptionMessage('Invalid UUID string: ');
+
+        Uuid::fromString('');
+    }
+
     public function testGetBytes(): void
     {
         $uuid = Uuid::fromString('ff6f8cb0-c57d-11e1-9b21-0800200c9a66');