Validate references via API instead of locally

Validation rules can change at any time, and the SDK must adapt to the
API. Local checks could block valid paths if Firebase loosens a rule, so
they’ve been removed.

Developers can be trusted not to use invalid paths 😅.

Author: jeromegamez

CHANGELOG.md

@@ -5,6 +5,12 @@ If it saves you or your team time, please consider [sponsoring its development](
 
 ## [Unreleased]
 
+### Changed
+
+* Realtime Database references are now validated by the API instead of locally. Validation rules can change at any time,
+  and the SDK can only adapt to changes in the API. While local checks could prevent obviously invalid paths, they’d
+  also require an SDK update whenever Firebase loosens a rule. Developers can be trusted not to use invalid paths 😅.
+
 ## [7.23.0] - 2025-10-13
 
 * Require `cuyz/valinor:^2.2.1` for better mapping.

src/Firebase/Database/Reference.php

@@ -4,7 +4,6 @@
 
 namespace Kreait\Firebase\Database;
 
-use Kreait\Firebase\Database\Reference\Validator;
 use Kreait\Firebase\Exception\DatabaseException;
 use Kreait\Firebase\Exception\InvalidArgumentException;
 use Kreait\Firebase\Exception\OutOfRangeException;
@@ -27,21 +26,13 @@
  */
 class Reference implements Stringable
 {
-    private readonly UriInterface $uri;
-
     /**
      * @internal
-     *
-     * @throws InvalidArgumentException if the reference URI is invalid
      */
     public function __construct(
-        UriInterface $uri,
+        private readonly UriInterface $uri,
         private readonly ApiClient $apiClient,
-        private readonly Validator $validator = new Validator(),
     ) {
-        $this->validator->validateUri($uri);
-
-        $this->uri = $uri;
     }
 
     /**
@@ -89,19 +80,15 @@ public function getParent(): self
             throw new OutOfRangeException('Cannot get parent of root reference');
         }
 
-        return new self(
-            $this->uri->withPath('/'.ltrim($parentPath, '/')),
-            $this->apiClient,
-            $this->validator,
-        );
+        return new self($this->uri->withPath('/'.ltrim($parentPath, '/')), $this->apiClient);
     }
 
     /**
      * The root location of a Reference.
      */
     public function getRoot(): self
     {
-        return new self($this->uri->withPath('/'), $this->apiClient, $this->validator);
+        return new self($this->uri->withPath('/'), $this->apiClient);
     }
 
     /**
@@ -117,11 +104,7 @@ public function getChild(string $path): self
         $childPath = sprintf('/%s/%s', trim($this->uri->getPath(), '/'), trim($path, '/'));
 
         try {
-            return new self(
-                $this->uri->withPath($childPath),
-                $this->apiClient,
-                $this->validator,
-            );
+            return new self($this->uri->withPath($childPath), $this->apiClient);
         } catch (\InvalidArgumentException $e) {
             throw new InvalidArgumentException($e->getMessage(), $e->getCode(), $e);
         }
@@ -323,7 +306,7 @@ public function push($value = null): self
         $newKey = $this->apiClient->push($this->uri->getPath(), $value);
         $newPath = sprintf('%s/%s', $this->uri->getPath(), $newKey);
 
-        return new self($this->uri->withPath($newPath), $this->apiClient, $this->validator);
+        return new self($this->uri->withPath($newPath), $this->apiClient);
     }
 
     /**

src/Firebase/Database/Reference/Validator.php

@@ -7,7 +7,6 @@
 use GuzzleHttp\Psr7\Uri;
 use Kreait\Firebase\Database\ApiClient;
 use Kreait\Firebase\Database\Reference;
-use Kreait\Firebase\Exception\InvalidArgumentException;
 use Kreait\Firebase\Exception\OutOfRangeException;
 use Kreait\Firebase\Tests\UnitTestCase;
 use PHPUnit\Framework\Attributes\Test;
@@ -77,13 +76,6 @@ public function getChild(): void
         $this->assertSame('parent/key/child', $child->getPath());
     }
 
-    #[Test]
-    public function getInvalidChild(): void
-    {
-        $this->expectException(InvalidArgumentException::class);
-        $this->reference->getChild('#');
-    }
-
     #[Test]
     public function getChildKeys(): void
     {

tests/Unit/Database/Reference/ValidatorTest.php

@@ -44,13 +44,6 @@ public function getRootReference(): void
         $this->assertSame('/', $this->database->getReference()->getUri()->getPath());
     }
 
-    #[Test]
-    public function getReferenceWithInvalidPath(): void
-    {
-        $this->expectException(InvalidArgumentException::class);
-        $this->database->getReference('#');
-    }
-
     #[Test]
     public function getReferenceFromUrl(): void
     {