Add shortcut for tag reference #333

src/CompositeContainer.php

@@ -8,7 +8,7 @@
 use Psr\Container\ContainerInterface;
 use RuntimeException;
 use Throwable;
-use Yiisoft\Di\Helpers\TagHelper;
+use Yiisoft\Di\Reference\TagReference;
 
 use function is_string;
 
@@ -54,7 +54,7 @@ public function get($id)
             return $stateResetter;
         }
 
-        if (TagHelper::isTagAlias($id)) {
+        if (TagReference::isTagAlias($id)) {
             $tags = [];
             foreach ($this->containers as $container) {
                 if (!$container instanceof Container) {

src/Container.php

@@ -17,7 +17,7 @@
 use Yiisoft\Definitions\Helpers\DefinitionValidator;
 use Yiisoft\Di\Helpers\DefinitionNormalizer;
 use Yiisoft\Di\Helpers\DefinitionParser;
-use Yiisoft\Di\Helpers\TagHelper;
+use Yiisoft\Di\Reference\TagReference;
 
 use function array_key_exists;
 use function array_keys;
@@ -101,8 +101,8 @@ public function __construct(ContainerConfigInterface $config)
      */
     public function has(string $id): bool
     {
-        if (TagHelper::isTagAlias($id)) {
-            $tag = TagHelper::extractTagFromAlias($id);
+        if (TagReference::isTagAlias($id)) {
+            $tag = TagReference::extractTagFromAlias($id);
             return isset($this->tags[$tag]);
         }
 
@@ -472,7 +472,7 @@ private function addDefinitionToStorage(string $id, $definition): void
      */
     private function build(string $id)
     {
-        if (TagHelper::isTagAlias($id)) {
+        if (TagReference::isTagAlias($id)) {
             return $this->getTaggedServices($id);
         }
 
@@ -502,7 +502,7 @@ private function build(string $id)
 
     private function getTaggedServices(string $tagAlias): array
     {
-        $tag = TagHelper::extractTagFromAlias($tagAlias);
+        $tag = TagReference::extractTagFromAlias($tagAlias);
         $services = [];
         if (isset($this->tags[$tag])) {
             foreach ($this->tags[$tag] as $service) {

src/Reference/TagReference.php

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Yiisoft\Di\Reference;
+
+use Yiisoft\Definitions\Reference;
+
+/**
+ * TagReference is a helper class that is used to specify a reference to a tag.
+ * For example, `TagReference::to('my-tag')` specifies a reference to all services that are tagged with `tag@my-tag`.
+ */
+final class TagReference
+{
+    private const PREFIX = 'tag@';
+
+    private function __construct()
+    {
+    }
+
+    public static function to(string $tag): Reference
+    {
+        return Reference::to(self::PREFIX . $tag);
+    }
+
+    public static function extractTagFromAlias(string $alias): string
+    {
+        if (!str_starts_with($alias, self::PREFIX)) {
+            throw new \InvalidArgumentException(sprintf('Alias "%s" is not a tag alias.', $alias));
+        }
+        return substr($alias, 4);
+    }
+
+    public static function isTagAlias(string $id): bool
+    {
+        return str_starts_with($id, self::PREFIX);
+    }
+}

tests/Unit/Reference/TagReferenceTest.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Yiisoft\Di\Tests\Unit\Reference;
+
+use InvalidArgumentException;
+use PHPUnit\Framework\TestCase;
+use Psr\Container\ContainerInterface;
+use Yiisoft\Di\Reference\TagReference;
+
+final class TagReferenceTest extends TestCase
+{
+    public function testAliases(): void
+    {
+        $this->assertFalse(TagReference::isTagAlias('test'));
+        $this->assertFalse(TagReference::isTagAlias('tag#test'));
+        $this->assertTrue(TagReference::isTagAlias('tag@test'));
+    }
+
+    public function testExtractTag(): void
+    {
+        $this->assertEquals('test', TagReference::extractTagFromAlias('tag@test'));
+    }
+
+    public function testExtractWrongTag(): void
+    {
+        $this->expectException(InvalidArgumentException::class);
+        TagReference::extractTagFromAlias('test');
+
+        $this->expectException(InvalidArgumentException::class);
+        TagReference::extractTagFromAlias('tag#test');
+    }
+
+    public function testReference(): void
+    {
+        $reference = TagReference::to('test');
+        $spyContainer = new class implements ContainerInterface {
+            public function get($id)
+            {
+                return $id;
+            }
+
+            public function has($id): bool
+            {
+                return true;
+            }
+        };
+
+        $result = $reference->resolve($spyContainer);
+
+        $this->assertEquals('tag@test', $result);
+    }
+}